Metaplastic breast carcinomas: are they of myoepithelial differentiation?: immunohistochemical profile of the sarcomatoid subtype using novel myoepithelial markers

We investigated 20 spindle cell (sarcomatoid) metaplastic carcinomas (MCs) without squamous differentiation. In addition, five high-grade phyllodes tumors were assessed for comparison. Our immunohistochemical antibody panel included pan-cytokeratin (CK), low molecular weight CK (CK8/18), four basal cell type CKs (34betaE12, CK5/6, CK14, and CK17), vimentin antibodies, as well as antibodies to established (SMA, CD10, p63, S-100, maspin, calponin, GFAP, SM-myosin), and novel (CD29, 14-3-3sigma) myoepithelial markers. Sixteen of the 20 tumors (80%) expressed at least two markers of the combination CD10/p63/SMA. S-100 detected 1 case negative for CD10/p63/SMA and 3 cases that only expressed one marker of this combination. While 18 MCs (90%) were positive for CD29, 14-3-3sigma (11 cases) and maspin (9 cases) were observed in 55% and 45%, respectively. Antibodies to pan-CK and the basal cell type CKs were strongly reactive in 12 tumors (60%), but in 6 cases (30%) positivity for these markers was weak and only focal; 2 MCs showed no positivity for CK. The stromal component of all phyllodes tumors was positive for vimentin, whereas all other investigated markers were absent except for focal p63 and CD10 expression in 1 case each. Our findings convincingly show a myoepithelial immunophenotype in sarcomatoid MCs, which is demonstrated by the presence of basal cell type CKs and the combination of the established myoepithelial markers CD10, p63, SMA, and S-100. We conclude that tumors with weak or even absent CK expression should only be diagnosed as primary sarcomas of the breast after exclusion of a myoepithelial immunophenotype. CD29 and 14-3-3sigma represent valuable novel myoepithelial markers in these diagnostically difficult cases.     

Detection of residual tumor cells in bladder biopsy specimens: pitfalls in the interpretation of cytokeratin stains

Some patients who have had prior bladder biopsies or transurethral resections undergo a repeat resection within several months for various reasons. The detection of a few residual tumor cells in bladder specimens with prior biopsy site changes can be challenging based on histology alone. Immunohistochemistry for cytokeratins may be used as an adjunct in this situation. We have noted several cases in which keratin stains were performed and positive cells were noted, raising the issue as to whether the cytokeratin positive cells were residual tumor cells or stromal cells. Immunohistochemistry for a panel of antibodies [AE1/AE3, CAM 5.2, high molecular weight cytokeratin, smooth muscle actin (SMA), desmin, and anaplastic lymphoma kinase (ALK)] was performed on 29 cases of bladder biopsies with prior biopsy site changes. Of 29 patients, 25 had a prior history of bladder tumor: 17 had invasive high-grade urothelial carcinoma (T1, 5 cases; T2, 11 cases; T3,1 case); 7 had noninvasive high-grade papillary urothelial carcinoma; 1 had noninvasive low-grade papillary urothelial carcinoma). One of the patients with noninvasive high-grade papillary urothelial carcinoma and one of the patents with invasive high-grade urothelial carcinoma had associated carcinoma in-situ. Four patients had prior benign bladder diagnoses: cystitis cystica et glandularis; polypoid cystitis; follicular cystitis; and neurogenic bladder with benign prostate hyperplasia. Of the 29 cases, 6 (21%) had cells with staining for at least 2 of the cytokeratin markers. Cytokeratin (CK) AE1/ AE3 was positive for cells in 8/29 cases (28%). In 6 of these cases, cells displayed a spindle cell and 2 cases a more epithelioid morphology. CAM 5.2 was positive in cells in 5/29 cases (17%); 3 of the cases had spindle cell and 2 cases epithelioid morphology. High molecular weight cytokeratin was expressed in cells in 2/29 cases (7%) with 1 case having spindle cell and 1 epithelioid morphology. SMA was positive in cells with a spindle cell morphology and negative in the more epitheloid cytokeratin positive cells. Desmin was positive in 3/6 keratin positive spindle cells and negative in keratin positive epithelioid cells. ALK was negative in all the cases. Three cases with spindle cell morphology and positivity for at least 1 of the keratins and SMA stains were interpreted as aberrant keratin expression in myofibroblastic cells based on the staining and the morphology of the spindle cells. Another 3 cases with concurrent staining for at least 1 of the keratins, SMA and desmin were consistent with smooth muscle cells on the basis of their cellular morphology. Another 2 cases had cells, which expressed at least 2 CK markers but did not express SMA, desmin, or ALK and a more epithelioid morphology. These cells were interpreted as residual tumors cells. When interpreting CK stains for the detection of residual tumor cells, one should pay attention to the nature of the cells and not assume all CK staining cells are residual tumor cells.     

Mammary NOS-type sarcoma with CD10 expression: a rare entity with features of myoepithelial differentiation

We present an extensive immunohistochemical analysis of 7 mammary sarcomas that did not fit into any specific soft tissue sarcoma category. Histologically, they were composed of spindle cells with highly pleomorphic nuclei and abundant mitoses. Our immunohistochemical antibody panel included pan-cytokeratin (CK), basal cell type CKs (34betaE12, CK5/6, CK14, CK17) and vimentin antibodies, antibodies to established (SMA, CD10, p63, S-100, maspin, calponin, GFAP, SM-myosin), and novel (CD29, 14-3-3sigma) myoepithelial markers, as well as antibodies to CD34, desmin, h-caldesmon, steroid receptors (estrogen, progesterone, androgen), and EGFR (Her-1). Whereas CKs, CD34, desmin, and h-caldesmon were not expressed, all tumors were positive for CD10 and vimentin. CD29 and SMA were observed in 3 cases each (43%), and p63 and calponin in 2 cases each (29%). Other myoepithelial markers and steroid receptors were absent, except androgen receptors, which were expressed in one sarcoma. Five sarcomas showed positivity for EGFR. The distinction of specific, histogenetically defined sarcoma entities (such as leiomyosarcoma, angiosarcoma, liposarcoma) from NOS-type sarcoma with CD10 expression is usually clear-cut because the former exhibit a characteristic histomorphology and immunoprofile. Phyllodes tumors with stromal overgrowth or recurrent phyllodes tumors lacking epithelial structures as well as periductal stromal sarcomas can be ruled out by their frequent expression of CD34 and negativity for myoepithelial markers. The most important differential diagnosis is sarcomatoid metaplastic carcinoma because its treatment includes axillary lymphadenectomy. Since some NOS-type sarcomas with CD10 expression and most metaplastic carcinomas show positivity for CD29, SMA, and p63, differential diagnosis can be extremely difficult and requires extensive immunohistochemical evaluation for CKs and additional myoepithelial markers such as S-100, 14-3-3sigma, and maspin. The immunophenotype of NOS-type sarcomas with CD10 expression suggests that these neoplasms represent a mammary sarcoma variant with myoepithelial features.     

Inflammatory myofibroblastic tumors of the urinary tract: a clinicopathologic study of 46 cases, including a malignant example inflammatory fibrosarcoma and a subset associated with high-grade urothelial carcinoma

Inflammatory myofibroblastic tumor (IMT) of the urinary tract, also termed postoperative spindle cell nodule, inflammatory pseudotumor, and pseudosarcomatous fibromyxoid tumor, is rare and in the past was believed to reflect diverse entities. We reviewed a series of 46 IMTs arising in the ureter, bladder, and prostate, derived primarily from a large consultation practice. There were 30 male and 16 females aged 3 to 89 years (mean 53.6). Lesions were 1.2 to 12 cm (mean 4.2). There was a history of recent prior instrumentation in 8 cases. Morphology was similar to that previously described for IMT occurring in this region, with the exception of 1 case that focally appeared sarcomatous. Polypoid cystitis coexisted in 5 patients (11%). Mitoses were typically scant (0 to 20/10 hpf, mean 1). Necrosis was seen in 14 (30%) cases. Invasion of the muscularis propria was documented in 19 (41%). By immunohistochemistry (IHC), lesions at least focally expressed anaplastic lymphoma kinase (ALK) (20/35, 57%), AE1/3 (25/34, 73%), CAM5.2 (10/15, 67%), CK18 (6/6, 100%), actin (23/25, 92%), desmin (15/19, 79%), calponin (6/7, 86%), caldesmon (4/7, 57%, rare cells), p53 (10/13, 77%), and most lacked S100 (0/14), CD34 (0/13), CD117 (2/13, 15%), CD21 (0/5), and CD23 (0/3). ALK gene alterations were detected by fluorescence in situ hybridization (FISH) in 13/18 (72%) tested cases, including 2 with prior instrumentation; 13/18 (72%) showed agreement between FISH ALK results and ALK protein results by IHC. Most bladder IMTs were managed locally, but partial cystectomy was performed as the initial management in 7 cases and cystectomy in 1 (1 IMT was initially misinterpreted as carcinoma, 1 IMT was found incidentally as a separate lesion in a cystectomy specimen performed for urothelial carcinoma). Follow-up was available in 32 cases (range 3 to 120 mo; mean 33; median 24). There were 10 patients with recurrences (2 with 2 recurrences). Recurrences were unassociated with muscle invasion or with ALK alterations. In 2 cases, tumors of the urinary tract (TURs) showing IMT preceded (1 and 2 mo, respectively) TURs showing sarcomatoid carcinoma with high-grade invasive urothelial carcinoma accompanied with separate fragments of IMT. Even on re-review the IMT in these 2 cases were morphologically indistinguishable from other cases of IMT, with FISH demonstrating ALK alterations in the IMT areas in one of them. Both these patients died of their carcinomas. Lastly, there was 1 tumor with many morphological features of IMT and an ALK rearrangement, yet overtly sarcomatous. This case arose postirradiation for prostate cancer 4 years before the development of the lesion, with tumor recurrence at 4 months and death from intra-abdominal metastatic disease at 9 months. In summary, urinary tract IMTs are rare and share many features with counterparts in other sites, displaying similar morphology and immunogenotypic features whether de novo or postinstrumentation. Typical IMTs can be locally aggressive, sometimes requiring radical surgical resection, but none of our typical cases metastasized, although they can rarely arise contemporaneously with sarcomatoid urothelial carcinomas. For these reasons, close follow-up is warranted.     

Sarcomatoid carcinoma of the penis: a clinicopathologic study of 15 cases

Sarcomatoid carcinomas are uncommon, high-grade tumors, predominantly composed of spindle cells. Only a few cases arising in the penis have been reported. The aim of this study is to better define the clinicopathologic features of this neoplasm. A total of 400 cases of squamous cell carcinoma of the penis were reviewed from which 15 sarcomatoid carcinomas (4%) were identified. Clinical and pathologic features were evaluated in all cases. Immunohistochemical studies for expression of AE1/AE3, Cam 5.2, 34betaE12, EMA, vimentin, muscle specific actin, smooth muscle actin, desmin, S-100, p63, and p53 and in situ hybridization studies for HPV were performed in 5 cases. Information about lymph node status was available in 9 cases, and follow-up in 5 cases. The mean age was 59 years, and mean tumor size was 5 cm. Grossly, most tumors were large, polypoid, and ulcerated masses frequently affecting the glans (93%) and deeply invading corpora cavernosa (80%) and skin. Microscopically, the lesions were predominantly composed of atypical spindle cells disposed in interlacing fascicles, resembling fibrosarcoma or leiomyosarcoma, sometimes admixed with pleomorphic giant cells mimicking malignant fibrous histiocytoma. One case was predominantly composed of myxoid areas. Less frequent and focal patterns were pseudoangiomatous and epithelioid. Mitotic figures were numerous, and necrosis was prominent. Foci of heterologous differentiation toward bone (osteosarcomatous component) were present in 1 case. Four cases showed a minor mixed component of usual, papillary, verrucous, and basaloid carcinoma. Intrapenile metastasis ("satellitosis") was present in 4 tumors. One of the cases was multicentric with a separate independent focus of well-differentiated carcinoma with pseudohyperplastic features. Associated low- and high-grade squamous intraepithelial lesions were noted in 73% of the cases. Immunohistochemical studies and HPV in situ hybridization were done in 5 cases. The spindle cells were diffusely positive for vimentin and p53 and showed at least intermediate expression of 34betaE12 and p63 in all cases. EMA and AE1/AE3 were focally positive in 60% of the cases, and Cam 5.2 was focally positive in 1 case. Tumor cells failed to express muscle specific actin, smooth muscle actin, desmin, and S-100. HPV in situ hybridization was negative in all cases. Inguinal metastases were present in 89% of the cases. Two of five patients with adequate follow-up died of disease within 8 months of the diagnoses. In conclusion, penile sarcomatoid carcinomas are unusual, large, and aggressive tumors usually associated with lymph node metastasis and poor outcome. Differential diagnoses include sarcoma and melanoma. Cytokeratin 34betaE12 and p63 appear to be the more specific and sensitive markers to categorize these tumors as epithelial. Diffuse immunoreactivity for p53, compared with a more basal and focal reactivity in differentiated squamous cell carcinoma, may be indicative of a late mutation in the natural progression of the disease.     

Basal cell cocktail (34betaE12 + p63) improves the detection of prostate basal cells

Antibodies against high molecular weight cytokeratin (34betaE12) and p63 are frequently used basal cell markers to aid in the diagnosis of prostate cancer (Pca). Absence of a basal cell marker in an atypical lesion histologically suspicious for cancer supports a diagnosis of Pca. However, absence of basal cells demonstrable by basal cell immunohistochemistry (IHC) is not always conclusive for PCa. Some benign prostatic lesions may have inconspicuous or even lack basal cell lining focally. Technical factors such as tissue fixation and antigen retrieval techniques may also make the detection of basal cells difficult. Improving the sensitivity of current basal cell markers is critical if these tests are being used to help make diagnostic decisions in conjunction with standard histology. In this study, we test the hypothesis that that inclusion of both 34betaE12 and p63 in the same IHC reaction (basal cell cocktail) is advantageous over either marker used alone. One thousand three hundred fifty glands from 9 trans-urethral resectioned of prostate specimens with benign prostatic hypertrophy were used to study the immunostaining intensity and pattern for 34betaE12, p63, and the basal cell cocktail. Basal cell marker expression was scored as strong, moderate, weak, or negative. Basal cell staining was considered complete if 75% of the gland's circumference was positive for the basal cell marker and partial if <25% of the circumference was stained. The mean staining intensity and variance were calculated for 34betaE12, p63, and the basal cell cocktail. A paired test was used to evaluate whether the overall basal cell staining was significantly different between 34betaE12, p63, and the basal cell cocktail. F-test was used to assess the variances for 34betaE12, p63, and the basal cell cocktail. A high-density tissue microarray (TMA) comprising prostate tissue from 103 tumors from men with clinically localized Pca and a separate TMA comprising metastatic hormone-refractory Pca samples from 23 rapid autopsy cases were used to study the aberrant expression of 34betaE12 and p63 in clinically localized and poorly differentiated Pca. The prostate glands in transition zone have variable basal cell staining intensity and pattern with 34betaE12, p63, or the cocktail. Histologically, benign glands lack basal cell lining in 2%, 6%, and 2% of glands with cocktail, 34betaE12, and p63 staining, respectively. The staining variance for the cocktail is significantly smaller than that for 34betaE12 (0.0100 vs 0.1559, p = 0.0008). It is also smaller than that for p63, although a statistical significance has not been reached (0.0100 vs 0.0345, p = 0.099). The basal cell cocktail stains the basal cell layers more intensely than either 34betaE12 or p63 alone, with complete and partial strong basal cell staining in 93% and 1% of benign glands, compared with 55% and 4% with 34betaE12 and 81% and 1% with p63. Complete and partial weak staining is seen in 0% and 0% of benign glands with basal cell cocktail, compared with 8% and 7% with 34betaE12 and 4% and 1% with p63 (p = 0.007 and 0.014 for cocktail vs 34betaE12 and cocktail vs p63, respectively). A total of 2.8% clinically localized Pca had positive 34betaE12 staining and 0.3% had positive p63 staining. Five (22%) of the metastatic Pca is positive for 34betaE12. However, none had p63 expression. The basal cell cocktail had a staining pattern identical to that of 34betaE12. IHC of the prostatic glands from the transition zone is subjected to staining variability that results in frequent variable and occasional negative basal cell staining in histologically benign glands; 34betaE12 is most susceptible, and basal cell cocktail is least susceptible to such variability. Basal cell cocktail not only increases the sensitivity of the basal cell detection, but also reduces the staining variability and therefore renders the basal cell immunostaining more consistent. We recommend this basal cell cocktail for routine Pca diagnostic work-up.     

Middle Ear Adenomas Stain for Two Cell Populations and Lack Myoepithelial Cell Differentiation

Middle ear adenomas (MEAs) are benign neoplasms along a spectrum with neuroendocrine neoplasms (carcinoid tumors). Immunohistochemical (IHC) staining for myoepithelial markers has not been reported in these tumors. The archives of the Cleveland Clinic, University of Virginia and Armed Forces Institute of Pathology were retrospectively searched for tumors arising within the middle ear with material available for IHC staining. Twelve cases of MEAs, four cases of jugulotympanic paragangliomas (JPGs), 10 cases of ceruminous adenomas (CAs) and four cases of ceruminous adenocarcinomas (CACs) were obtained. IHC staining was performed for smooth muscle actin (SMA), p63, S-100 protein, cytokeratin 5/6 (CK5/6), and cytokeratin 7 (CK7). The MEAs were positive for: CK7 (92 %, luminal), CK5/6 (92 %, abluminal), p63 (83 %, abluminal), and negative for SMA and S-100 protein. The JPGs were negative for CK7, CK5/6, p63 and SMA; S-100 protein highlighted sustentacular cells. The CAs were positive for: CK7 (100 %, luminal), CK5/6 (100 %, abluminal), S-100 protein (80 %, abluminal), p63 (100 %, abluminal), and SMA (90 %, abluminal). CACs demonstrated two patterns, (1) adenoid cystic carcinoma-type: positive for CK7 (100 %, luminal), CK5/6, S-100 protein, p63, and SMA (all 100 %, abluminal); and (2) conventional-type: CK7 (50 % luminal), and no CK5/6, SMA, S-100 protein, or p63 expression. The IHC profile of MEAs suggests that these tumors harbor at least two cell populations, including luminal and basal cells. However, unlike ceruminous adenomas, MEAs lack true myoepithelial differentiation given the absence of S-100 protein and SMA staining in all cases.     

Comparison of the basal cell-specific markers, 34betaE12 and p63, in the diagnosis of prostate cancer

The basal cell-specific cytokeratin antibody (34betaE12) is widely used to aid in the diagnosis of cancer in challenging prostate needle biopsies (NBX) and transurethral resections of the prostate (TURP). Because prostate carcinoma (PCa) lacks basal cells, the absence of basal cell as determined by 34betaE12 can aid in the confirmation of a histologically suspicious lesion. However, false-negative staining occurs because of patchy cytoplasmic staining, making a definitive diagnosis difficult. A recently identified basal cell marker p63, a p53 homologue, stains basal cell nuclei but not secretory cells. The aim of this study is to determine if the p63 antibody offers any clinically useful advantage over 34betaE12 in the diagnosis of challenging atypical prostate lesions. Ninety-four cases, comprised of 25 consecutive prostate NBX and 2 TURP with an atypical suspicious focus, 55 NBX cases of histologically unequivocal PCa and 12 TURP specimen removed for benign prostate hyperplasia, were stained with the monoclonal antibodies 34betaE12 and 4A4 anti-p63. Basal cell staining intensity, percentage basal cell-positive glands in benign, malignant, and atypical foci, and number of benign glands not staining were evaluated for 34betaE12 and p63 stains. A total of 67 prostate NBX cases, including one TURP, were diagnosed with PCa, 1 atypical small acinar proliferation, 10 benign, and 4 cases excluded because of lost tissue on step sections. None of the 67 PCa NBX cases demonstrated 34betaE12 or p63 immunoreactivity (100% specific). Whereas 57 of 108 (53%) prostate NBX cores from 78 cases demonstrated a similar percentage of basal cell staining for both antibodies, 45 of 108 (41%) NBX cores demonstrated a higher percentage of p63 basal cell staining in benign glands. Only 6 of 108 NBX (6%) cores had a higher percentage of basal cell staining with 34betaE12 (Wilcoxon signed rank test, p <0.0001). Lack of basal cell staining in more than two benign glands occurred in 25 of 108 (23%) and 10 of 108 (9%) prostate NBX cores stained with 34betaE12 and p63, respectively. In the vast majority of atypical cases, both 34betaE12 and p63 staining differences were not clinically significant, except in 2 of 27 (7%) cases p63 offered diagnostic utility beyond the 34betaE12 immunostain. p63 in these cases demonstrated discontinuous but strong staining in atypical glands and adjacent benign glands, whereas 34betaE12 failed to stain optimally in this critical area. For 12 TURP cases the mean percentage basal cell positivity in benign glands was 75% and 95% for 34betaE12 and p63, respectively (p = 0.006). Lack of basal cell staining in more than two glands occurred in 12 of 12 (100%) and 2 of 12 (17%) TURP specimens stained with 34betaE12 and p63, respectively (p <0.0001). In summary, 34betaE12 and p63 are highly specific for basal cells and therefore are negative in areas of PCa. p63 is more sensitive than 34betaE12 in staining benign basal cells, particularly for TURP specimens, offering slight advantage over 34betaE12 in diagnostically challenging cases. p63 may be used as an alternative to 34betaE12 stain for difficult prostate lesions.     

Cytokeratins in papillary lesions of the breast: is there a role in distinguishing intraductal papilloma from papillary ductal carcinoma in situ?

We studied 50 papillary lesions (25 papillomas and 25 papillary ductal carcinomas in situ, DCIS) diagnosed at Singapore General Hospital, for immunohistochemical expression of cytokeratin (CK) 5/6, CK14, and 34betaE12. The immunoscore (proportion of stained cells multiplied by staining intensity) was compared between the two groups. Cytokeratin expression was corroborated by confocal microscopy. Results were applied to a separate series of 43 papillary tumors from Hong Kong (HK). CK5/CK6, CK14, and 34betaE12 showed higher immunoscores in papillomas (mean values, 107.6, 186.6, and 113.1, respectively) than papillary DCIS (mean values, 12, 29.6, and 34.5, respectively; P<0.0001, P<0.001, and P<0.02, respectively). A cutoff immunoscore threshold of 50 appeared discriminatory between papilloma and papillary DCIS, and this value was applied to the HK cases, with CK5/CK6, CK14, and 34betaE12 correctly predicting 25 (89.3%), 26 (92.9%), and 27 (96.4%), respectively, of 28 HK lesions labeled as papillomas; while they corroborated 13 (86.7%), 13 (86.7%), and 5 (33.3%), respectively, of 15 HK cases diagnosed as papillary DCIS. Review of discordant cases showed that lesions were small, derived from core biopsies, or disclosed accompanying invasive carcinoma. When both SGH and HK cases were combined as a group, the sensitivity of an immunoscore of 50 or less in the diagnosis of papillary DCIS was 95%, 85%, and 62.5% for CK5/CK6, CK14, and 34betaE12, respectively, while the specificity was 86.8%, 94.3%, and 86.8%, respectively. CK immunohistochemistry can aid in evaluating papillary breast lesions. 34betaE12 does not appear as useful in identifying papillary DCIS.     

Ependymomas of the central nervous system and adult extra-axial ependymomas are morphologically and immunohistochemically distinct--a comparative study with assessment of ovarian carcinomas for expression of glial fibrillary acidic protein

Extra-axial ependymomas are very rare but have been reported in the ovary, broad ligament, sacrococcygeal region, lung, and mediastinum. The histogenesis is obscure, and a thorough immunohistochemical analysis is lacking. We reviewed the morphologic and immunohistochemical features of 5 extra-axial ependymomas occurring in adults, 1 arising in an infantile sacrococcygeal teratoma, and a control group of 10 central nervous system (CNS) ependymomas in adults. All cases were evaluated for expression of epithelial membrane antigen, estrogen receptor (ER), progesterone receptor (PR), WT1, CD99, CK18, AE1:3, CAM 5.2, 34betaE12, CK7, CK20, synaptophysin, chromogranin, and glial fibrillary acidic protein (GFAP) using formalin-fixed, paraffin-embedded tissue. One hundred twelve ovarian carcinomas in 3 tissue microarrays were also studied with GFAP. The adult extra-axial cases demonstrated more architectural variability than the CNS cases. We observed that both the CNS and adult extra-axial ependymomas expressed GFAP diffusely, whereas only 9 stage III, high-grade ovarian serous papillary carcinomas stained with GFAP (2 strongly and diffusely and 7 exhibiting focally weak expression). There were significant immunophenotypic differences between adult extra-axial and CNS ependymomas, with extra-axial cases preferentially expressing 34betaE12 (60% vs. 0%), CK18 (100% vs. 20%), CAM 5.2 (60% vs. 10%), CK7 (80% vs. 10%), ER (100% vs. 10%), and PR (80% vs. 20%). Two spinal cord ependymomas expressed CK18, 1 expressed CK7, and 1 expressed CAM 5.2. CNS ependymomas more frequently expressed CD99 (100% vs. 20%). The following stains were not differentially expressed: epithelial membrane antigen (expressed in 2 of 15 cases, including both extra-axial and CNS ependymomas), synaptophysin (1/15), chromogranin (0/15), WT1 (8/15), AE1:3 (10/15), and CK20 (0/15). The ependymal elements of the sacrococcygeal tumor failed to express 34betaE12, CK18, CAM 5.2, and CK7, like most CNS ependymomas. The morphologic and immunophenotypic differences between extra-axial and CNS ependymomas suggest that they derive from distinct precursors and/or differentiate along distinct pathways. The differential diagnosis of extra-axial ependymomas is extensive, and GFAP expression in primary ovarian serous carcinomas, although rare, could theoretically contribute to diagnostic difficulties. ER and PR expression in extra-axial ependymomas may provide targets for hormonal therapy.     

Prostatic basal cells in the peripheral and transitional zones: zonal variation in morphology and in immunophenotype

BACKGROUND: Benign prostatic hyperplasia and prostatic adenocarcinoma exhibit prominent zonal predilections. Basal cells from the transitional zone and from the peripheral zone are postulated to have different underlying biological properties. We studied basal cells in both prostatic zones. METHODS: Tissue microarrays (TMA) were prepared from 65 whole-mounted prostatectomy specimens with prostatic adenocarcinoma. The transitional zone and peripheral zone were sampled from each prostate. TMA sections were stained with a basal cell cocktail (CK 34betaE12 + p63). The immunostaining pattern and the morphology of basal cells were recorded. RESULTS: Triangular-shaped basal cells were highlighted by CK 34betaE12 cytoplasmic and p63 nuclear staining. These basal cells had their long axis oriented perpendicular to the basement membrane and their apex toward the lumen interdigited between secretory luminal cells. This morphology was seen in the majority of peripheral zone benign prostatic glands (92.0%) but only a minority of transitional zone benign prostatic glands (18.0%). Basal cells of the transitional zone showed weak or absent CK 34betaE12 staining in 65.9% of glands while maintaining p63. All glands with high-grade prostatic intraepithelial neoplasia (HGPIN) contained the triangular basal cells. In addition, basal cell clusters were identified in 8.7% of peripheral zone glands and 5.2% of HGPIN glands. CONCLUSIONS: Our results indicate that the basal cell morphology and the basal cell immunophenotype have a zonal variation. The finding of a unique morphology of basal cells and the presence of basal cell clusters in the peripheral zone suggests that the peripheral zone might be the stem/progenitor cell-rich area in the human prostates.     

AMACR(P504S)、P63、34βE12联合检测在前列腺癌早期诊断中的应用

目的:探讨AMACR(P504S)、P63、34βE12联合检测在前列腺癌(PCa)早期诊断中的临床应用价值。方法:应用即用型组合式单克隆抗体和双酶标记的免疫组化MaxvisionTM一步法检测42例PCa、12例高级别前列腺上皮内瘤变(HGPIN)和30例良性前列腺增生(BPH)穿刺活检标本中AMACR、P63、34βE12的表达情况。比较Glea-son评分各组中AMACR阳性表达情况。结果:AMACR、P63、34βE12抗原在PCa和BPH穿刺标本中的表达差异均有极显著性(P<0.01),PCa组织中AMACR阳性表达率为100%,无P63和34βE12表达;BPH组织中均无AM-ACR表达,P63和34βE12均高表达。HGPIN中AMACR的阳性表达率(91.67%)与BPH差异有极显著性(P<0.01),与PCa差异无显著性(P>0.05);P63和34βE12阳性表达率HGPIN(100%)与PCa差异有极显著性(P<0.01),而与BPH差异无显著性(P>0.05)。AMACR表达强弱与PCa的Gleason评分无关(P>0.05)。结论:AMACR是PCa高度敏感和特异的标志物,P63和34βE12联合标记基底细胞的特异性高,3者联合检测能增加前列腺穿刺活检标本诊断的准确性,在PCa早期诊断中具有重要的临床应用价值。     

Use of keratin 35betaE12 as an adjunct in the diagnosis of mammary intraepithelial neoplasia-ductal type--benign and malignant intraductal proliferations.

A variety of studies have investigated the role of low molecular weight (LMW) and high molecular weight (HMW) cytokeratin (CK) expression in the normal breast and invasive breast carcinomas. A few studies with small numbers of cases have addressed this issue in intraductal proliferations of the breast. This study investigates the expression of these CKs in a large series of ductal intraepithelial neoplasias of the breast. We examined 150 ductal carcinomas in situ (DCIS), 35 cases of intraductal hyperplasia (IDH), and 15 cases of atypical intraductal hyperplasia (AIDH). Immunohistochemistry was performed using monoclonal antibodies against CK-34betaE12 (HMW CK), CK-8, and CK-19 (LMW CK) on formalin-fixed, paraffin-embedded tissue. The intensity (0, +1, +2, +3) and percentage of positive intraductal cells (0-100%) were multiplied to obtain a score from 0 to 300. The immunoprofiles of IDH, AIDH, and DCIS were categorized into four groups showing negative or low (0-60), moderate (61-100), high (101-200), and very high (201-300) scores. All cases of IDH showed an intensely positive reaction (high to very high scores) for CK-34betaE12. In contrast, 90% of the DCIS showed a negative or only focal and weak reaction (negative or low score) for this antigen. The remaining 10% of DCIS showed a positive immunoreaction for CK-34betaE12 with moderate to high scores. All cases of florid IDH and 96% of cases of DCIS expressed CK-8 intensely with high to very high scores. Although CK-19 was strongly expressed in 97% of cases of IDH (high to very high scores), a very high score was also found in 80% of cases of DCIS that were positive for CK-19. Of the 15 AIDHs, 80% had a negative or only focal reaction (negative or low score) for CK-34betaE12 and the remaining 20% had a moderate to high score for this antigen. Although CK-8 was strongly positive in 87% of cases of AIDH (high to very high scores), only 53.5% of AIDHs showed intense positivity for CK-19. The present study clearly shows that the immunoprofile of IDH is different from DCIS as far as HMW CK is concerned. Although florid IDH is characterized by a diffuse and intense immunoreaction for HMW CK, the lack of or only weak positivity for HMW CK (CK-34betaE12) is, in most cases, a hallmark of ductal carcinoma in situ. The immunoprofile of AIDH is very similar to that of DCIS. The expression of CK-8 and CK-19 is not useful in separating the various categories of ductal intraepithelial proliferations of the breast. We recommend the use of CK-34betaE12 as an adjunct in the diagnosis of a variety of problematic intraductal proliferations of the breast.     

Lymphohistiocytoid variant of malignant mesothelioma of the pleura: a series of 22 cases

The lymphohistiocytoid variant of diffuse malignant mesothelioma is rare with very few cases described in the literature. It is characterized by mesothelial cells with a histiocytelike appearance and an associated dense lymphoid infiltrate. We studied clinicopathologic features and immunohistochemical patterns of a series of 22 cases. The histiocytelike cells had a mesothelial immunophenotype: AE1/AE3 (100%), calretinin (100%), CK5/6 (46%), and EMA (52%). The prominent lymphoid component showed a cytotoxic T-cell immunophenotype. Prognosis was similar to that of a large series of epithelioid diffuse malignant mesotheliomas. Formely, it was classified within the sarcomatoid type. We suggest that it should be reclassified as an epithelioid variant because of its similar behavioural characteristics. There was no evidence of Epstein-Barr virus-related infection.     

Primary mediastinal seminoma: a comprehensive assessment integrated with histology, immunohistochemistry, and fluorescence in situ hybridization for chromosome 12p abnormalities in 23 cases

Accurate diagnosis of mediastinal seminoma is critical because of its favorable response to radiation therapy and/or cisplatin-based chemotherapy. Immunohistochemical staining for OCT4 has recently been validated as a powerful tool for detecting gonadal seminoma. However, discrepancies between the genetic alterations and immunoprofiles of mediastinal and testicular seminomas have been reported, raising the question of whether techniques that are useful in the diagnosis of gonadal seminoma are applicable to its mediastinal counterpart. The present study was conducted to evaluate the morphologic and immunohistochemical characteristics and chromosomal abnormalities of 12p in 23 primary mediastinal seminomas and to compare their applicability as diagnostic tools. Dual-color fluorescence in situ hybridization (FISH) analyses for chromosome 12p and immunostains for OCT4, c-kit, placental-like alkaline phosphatase, CD30, and a panel of cytokeratins, including cytokeratin AE1/AE3 (AE1/3), high molecular weight cytokeratin (34betaE12, HMWCK), CAM5.2, cytokeratin 7 (CK7), cytokeratin 20 (CK20), and epithelial membrane antigen were performed. Lymphocytic infiltration was found in all 23 cases (100%). The incidence of other histologic characteristics were as follows: fibrous septa/stroma (21 cases, 91%), prominent tumor cell nucleoli (21 cases, 91%), clear tumor cell cytoplasm (20 cases, 87%), distinct tumor cell borders (20 cases, 87%), granulomatous inflammation (17 cases, 74%), cellular pleomorphism (10 cases, 43%), necrosis (8 cases, 35%), prominent cystic change (2 cases, 8%), intercellular edema (1 case, 4%), and syncytiotrophoblasts (1 case, 4%). The mean mitotic count was 4.4 (range 0 to 16) per 10 high-power fields. Moderate to strong nuclear OCT4 staining was identified in all 23 cases (100%). Seventeen tumors (74%) showed membranous expression of c-kit, with variable staining intensity and percentages. Weakly to moderately intense immunostaining for placental-like alkaline phosphatase was identified in 10 cases (43%) with occasional background staining artifact. The incidences of positive staining were 43% for AE1/3, 39% for HMWCK, 48% for CAM5.2, 39% for CK7, and 9% for epithelial membrane antigen, respectively. In most cases, these epithelial markers highlighted only a small proportion of tumor cells with variable intensities. Immunostaining for CD30 and CK20 was completely negative in all seminomas. Twenty-two seminomas (96%) revealed chromosome 12p abnormalities, including 12p amplification in 20 cases (87%) or i(12p) in 15 cases (65%). Lymphocytic infiltration is the most common histologic feature observed in primary mediastinal seminoma and both OCT4 immunostain and FISH for 12p abnormalities can be very helpful in diagnosing mediastinal seminoma. The intense staining pattern of OCT4 and the high sensitivity of FISH make them superior to other auxiliary diagnostic utilities for detecting seminoma. In addition, the incidences of cytokeratin expression of primary mediastinal seminoma are similar to those of its gonadal counterpart and pathologists must exercise caution in the interpretation of epithelial markers in mediastinal neoplasms.     

Subclassification of non-small cell lung carcinomas lacking morphologic differentiation on biopsy specimens: Utility of an immunohistochemical panel containing TTF-1, napsin A, p63, and CK5/6

The availability of targeted therapies has created a need for precise subtyping of non-small cell lung carcinomas (NSCLCs). The aim of this study was to assess the utility of immunohistochemical markers in subtyping poorly differentiated NSCLC and to compare the results of immunohistochemical staining on biopsies with the corresponding resections. Thirty-nine cases of NSCLC that could not be further classified on biopsy and had subsequent resection specimens were identified. Classification of the tumor was based on the resection specimen using the World Health Organization criteria. All biopsies and resections were stained with CK7, TTF-1, napsin A (novel aspartic proteinase of the pepsin family), p63, CK5/6, and 34βE12. The specimens included 20 adenocarcinomas (ACs), 15 squamous cell carcinomas (SCCs), and 4 large-cell carcinomas (LCCs). TTF-1 was positive in biopsies from 16 of 20 ACs, 2 of 4 LCCs, and none of the SCCs. p63 was positive in all 15 SCCs, 2 of 20 ACs (both were also positive for TTF-1 and napsin A), and none of the LCCs. CK5/6 was positive in 11 of 15 SCCs (all p63 positive) but none of the ACs or LCCs. Napsin A stained 11 of 19 ACs (all TTF-1 positive) but none of the other tumors. Staining for CK7 was present in 19 of 19 ACs and 9 of 15 SCCs. 34βE12 stained both SCCs (15 of 15) and ACs (12 of 20). The combination of TTF-1, napsin A, p63, and CK5/6 allowed an accurate classification of 30 of39 (77%) cases. Of 232 pairs of slides (biopsy and resection) stained with immunohistochemical markers, 12 (5%) showed discrepancies in immunohistochemical staining between biopsies and their corresponding resections. Immunohistochemical staining using a combination of TTF-1, napsin A, p63, and CK5/6 allows subclassification of poorly differentiated NSCLCs on small lung biopsies in most cases. Discrepancies in immunohistochemical staining between biopsies and resections are uncommon.     

胰腺浆液性小囊性腺瘤临床与病理分析:附四例

目的 分析胰腺浆液性小囊性腺瘤(serous microcystic adenoma,sMA)的临床、病理特点及治疗.方法 回顾性分析4例sMA的临床表现、病理特征及治疗结果 .行PAS染色及CK7、CK20、AE1/AE3、EMA、CA19-9、CEA、34βE12、P63、SMA、Vim、S-100、CgA、Syn、NSE、ER、PR等免疫组织化学检测.结果 病人平均年龄66岁,因体检发现肿块或因其它疾病人院.巨检肿块呈蜂窝状,镜下见大小不等囊腔,囊内衬单层立方或扁平上皮,胞质透亮或嗜酸性.小囊间为胶原纤维分隔.肿瘤无包膜.上皮PAS染色及CK7、EMA、AE1/AE3均全部弥漫阳性.病人均出现手术并发症.结论 胰腺sMA好发于老年人,多为偶然发现.肉眼观呈蜂窝状,镜下小囊内衬一致性富于糖原的上皮,无包膜.免疫组化检测CK7、EMA、AE1/AE3全部阳性.肿块局部彻底切除是最佳治疗方案,但对于无症状的手术耐受力差的病人建议明确诊断后行保守治疗.     

从膀胱癌患者分离并培养人膀胱平滑肌细胞

目的：建立从膀胱癌患者的分离并培养膀胱平滑肌细胞的实验技术.方法：取一小块无明显肿瘤生长的膀胱组织,分离并培养膀胱平滑肌细胞;动态观察细胞形态变化、生长增殖情况以及平滑肌肌动蛋白（SMA）、结蛋白（Desmin）和广谱细胞角蛋白（AE1/AE3）的表达.结果：接种24 h后即有长梭形细胞贴壁生长,10天后长至80%融合,呈典型的＂峰谷＂样形态;传代后1天为潜伏期,2～6天为指数生长期,然后进入融合平台期,需再次传代.第2代细胞的SMA和Desmin表达阳性率分别高达（99.0±0.8）%和（97.0±2.1）%,不表达AE1/AE3.随着传代次数的增加,细胞去分化,细胞形态变成短梭状或椭圆形;SMA和Desmin的表达开始下降,传至第5代时,SMA和Desmin阳性率分别降至（78.0±3.3）%和（74.0±2.6）%;至第7代时,SMA和Desmin阳性率降至（51.0±3.0）%和（49.0±2.6）%.第7代细胞经血清饥饿培养48 h后,细胞又能再分化,形态转变成长梭状,SMA和Desmin阳性率可分别升至（90.0±3.5）%和（88.0±2.5）%,具有显著性差异.结论：本研究所培养的人膀胱平滑肌细胞具有较高的纯度,血清饥饿能促进去分化的细胞再分化,能为构建组织工程膀胱提供种子细胞.     

Basaloid squamous carcinoma of the anal canal with an adenoid cystic pattern: histologic and immunohistochemical reappraisal of an unusual variant

Two cases of a distinctive variety of basaloid squamous carcinoma (BSC) of the anal canal are described. Both occurred in female patients who presented with bleeding per rectum. Histologic evaluation of the tumors showed lobules and aggregates of medium-sized basaloid cells with distinctive peripheral palisading and focal areas of central, comedo-necrosis. Accompanying dysplasia of the overlying squamous mucosa was absent. However, the microscopic pattern was dominated by the presence of eosinophilic, hyaline, paucicellular basement membrane-like material around and within tumor nests. This appearance together with microcystic spaces simulated that of an adenoid cystic carcinoma. Immunohistochemistry of the tumors revealed the following profile: CK7, CK5/CK6, 34betaE12 positive, CK14 focally positive but CK20 negative. The following were all negative: EMA, CEA, smooth muscle and muscle-specific actin, calponin, and S-100. The tumor cells exhibited diffuse nuclear positivity with p63. The eosinophilic basement membrane hyaline material was positive for collagen type IV and also for laminin. BSC of the anal canal with an adenoid cystic pattern is an infrequently encountered and reported variant, although it is seen more often in the aerodigestive tract. There may be an increased propensity for BSC with an adenoid cystic pattern to metastasize to the liver, but the number of cases encountered are too small to be definitive. The histologic differential diagnosis is true salivary gland-type adenoid cystic carcinoma and basal cell adenocarcinoma. Immunohistochemistry and awareness of this unusual pattern of BSC will facilitate the correct diagnosis being reached.     

Sarcomatoid urothelial carcinoma with choriocarcinomatous features: first report of an unusual case

A 61-year-old man presented with gross hematuria and a polypoid right lateral bladder mass. The tumor was composed of conventional urothelial carcinoma with sarcomatoid and choriocarcinomatous features, both positive for epithelial markers (pancytokeratin, AE1/AE3, and CAM 5.2). In addition, choriocarcinomatous tumor cells were positive for beta human chorionic gonadotropin and placental alkaline phosphatase. Treatments included surgery, chemotherapy, and radiation therapy. The clinical course was aggressive, with liver, lung, and distant lymph node metastases and a postdiagnosis survival of 6 months. This is the first report, to our knowledge, indicating both sarcomatoid and choriocarcinomatous features in a conventional urothelial carcinoma of the bladder.