An immunohistochemical study of thymic epithelial tumors. II. Lymphoid component

The cellular composition and characteristics of lymphocytes and histiocytes in nine cases of thymoma and one case of squamous cell carcinoma of the thymus were studied immunohistochemically, using a panel of monoclonal and polyclonal antibodies. Nine cases of thymoma were subclassified into seven cases of mixed type and one case each of predominantly lymphocytic type and predominantly epithelial type. Two metastatic tumors and one recurrent tumor were included. Almost all the lymphocytes in the mixed type and lymphocytic type categories, either in primary site or metastasis, were T lymphocytes which showed the immature thymic lymphocyte-phenotype of the normal thymic cortex. On the other hand, the one epithelial thymoma contained many mature T lymphocytes along with immature T cells, as in the normal thymic medulla. In thymic squamous cell carcinoma, all infiltrating T lymphocytes were mature T lymphocytes. These findings suggest that epithelial cells of thymomas have an intimate relationship with the coexisting lymphocytes and retain functional properties of the normal thymic epithelial counterpart. On the other hand, the specific function of thymic epithelial cells is no longer maintained in thymic squamous cell carcinoma.     

An immunohistochemical study of thymic epithelial tumors. I. Epithelial component

Twenty-four cases of thymic epithelial tumors, including 18 cases of thymoma, five cases of squamous cell carcinoma, and one case of undifferentiated carcinoma, were studied immunohistochemically using monoclonal antibody Leu-7 (HNK-1) and antikeratin antibody. Seven cases of non-neoplastic thymic tissues were also studied. Leu-7 antibody stained epithelial cells in the outer cortex of the normal thymus, and antikeratin antibody stained thymic epithelial cells in both cortex and medulla of the normal thymus. Seventeen thymomas and one undifferentiated carcinoma were focally or diffusely stained with Leu-7, some showing cortical and medullary differentiation as seen in the normal thymus. On the other hand, none of the five squamous cell carcinomas were stained with Leu-7. All thymomas stained for keratin in varying degrees, and all squamous cell carcinomas were diffusely and strongly stained with antikeratin antibody. It is concluded that normal thymic epithelial cells showed zonal differentiation, and neoplastic cells were considered to retain these characteristics to some extent; i.e., thymomas had the same phenotype of epithelial cells of the cortex, especially the outer cortex of the thymus in some instances (Leu-7-positive, keratin-positive) and of both cortex and medulla (mixture of Leu-7-positive and -negative cells) with organoid arrangement in other instances, and thymic squamous cell carcinoma had the same phenotype as epithelial cells in the thymic medulla (Leu-7-negative, keratin-positive).     

S-100 protein in salivary gland tumors: an immunohistochemical study of 129 cases

Immunohistochemical distribution of S-100 protein was evaluated in 129 tumors from major and minor salivary glands. Also, two sensitive immunoperoxidase avidin-biotin methods using either overnight incubation with primary antibody or pretreatment trypsin digestion and half-hour incubation were compared. Tumors with S-100 protein immunoreactivity were demonstrated in numerous benign and malignant histologic categories. Adenoid cystic carcinomas, carcinomas ex pleomorphic adenoma, clear cell carcinomas, and adenocarcinomas NOS showed inconsistent positive staining, whereas all monomorphic and pleomorphic adenomas and polymorphous low grade adenocarcinomas examined stained positively. No staining was observed in mucoepidermoid carcinomas or acinic cell carcinomas. Mesenchymal-like tumor cells with positive immunostaining were seen only in pleomorphic adenomas and trabecular-tubular adenomas. Equivalent results were found with both overnight and same-day digestion techniques. The consistent S-100 protein staining in some histologic tumor categories (pleomorphic and monomorphic adenoma and polymorphous low grade adenocarcinoma) compared to mucoepidermoid carcinoma that is devoid of S-100 protein immunoreactivity has application to some microscopic differential diagnostic situations. Inconsistent staining of adenoid cystic carcinomas and adenocarcinomas did not allow discrimination from other benign and malignant salivary gland tumors with similar histomorphology.     

An immunoperoxidase study of S-100 protein distribution in normal and neoplastic tissues

The presence of S-100 protein was immunohistochemically studied in many types of formalin-fixed and paraffin-embedded tumors (260 cases). Peripheral nerve tumors, i.e., schwannomas, neurofibromas, granular cell tumors, and neurogenic sarcomas were demonstrated to contain variable amounts of S-100 protein in the tumor cell cytoplasm and nuclei. In ganglioneuromas and ganglioneuroblastomas, neoplastic Schwann cells or satellite cells were positive for S-100 protein. About one-half of the cases of carcinoid tumors stained weakly for S-100 protein. In addition to these nervous tissue and carcinoid tumors, chondrosarcoma, chordomas, pleomorphic adenomas of the salivary gland, and Langerhans cell granulomatosis were also shown to produce S-100 protein. In many types of breast tumors and other lesions, S-100 protein positive cells were likely to correspond to the distribution of myoepithelial cells. These results indicate that S-100 protein is not strictly specific to nervous tissue and its tumors; however, the immunohistochemical demonstration of S-100 protein can be a useful diagnostic tool in tumor diagnosis.     

Spindle cell thymic carcinoma: clinicopathologic and immunohistochemical study of a distinctive variant of primary thymic epithelial neoplasm.

We report 16 cases of a distinctive variant of primary thymic epithelial neoplasm characterized by prominent spindling of the tumor cells. The patients were seven women and nine men aged 23 to 82 years (mean, 54 years). The lesions presented as anterior mediastinal masses without clinical or radiographic evidence of tumor elsewhere. Most patients had chest pain, dyspnea, and cough; in five patients, the tumors were asymptomatic and were discovered on routine clinical examination. Grossly, the lesions were firm, well-circumscribed, and locally infiltrative, and had a firm cut surface with foci of hemorrhage, necrosis, and cystic changes. Most of the tumors were treated by complete surgical excision. Histologically, they were characterized by a spindle cell proliferation showing varying degrees of atypia and mitotic activity. In 12 cases, transitions could be seen with areas that showed the features of conventional spindle cell thymoma. In two cases, areas showing features of poorly differentiated (lymphoepitheliomalike) carcinoma and anaplastic carcinoma could also be observed. Immunohistochemical studies in 10 cases showed strong positivity of the spindle tumor cells for CAM5.2 cytokeratin, and negative staining for a panel of antibodies including epithelial membrane antigen, carcinoembryonic antigen, actin, desmin, vimentin, S-100 protein, HMB45, CD34, CD5, and CD99. Clinical follow-up of eight patients showed an aggressive biologic behavior with recurrence, metastasis, and death by tumor in five of them 2 to 5 years after diagnosis. Based on these findings, the present tumors are interpreted as an unusual spindle cell variant of thymic carcinoma. The close association of these cases with areas showing the features of spindle cell thymoma within the same tumor mass suggests that some of these lesions may arise as a result of malignant transformation in a preexisting spindle cell thymoma.     

Flow cytometric study of lymphocytes associated with thymoma and other thymic tumors

BACKGROUND. A large number of immature T lymphocytes in thymoma may reflect the biological function of the neoplastic epithelial cells. However, to confirm that this lymphocyte-inducing activity is unique to thymoma, lymphocytes associated with other thymic tumors need to be studied. MATERIALS AND METHODS. We used flow cytometry to study lymphocytes recovered from various thymic tumors (65 thymomas, 24 with myasthenia gravis; 5 thymic cancers; 5 germ cell tumors including 3 needle biopsy samples; and 2 other tumors) and results were analyzed in reference to those from 36 normal thymuses. RESULTS. The frequency of CD4(+)CD8(+) (DP) thymocytes in the normal thymus declined with age (0.9-94%, r = -0.83, P < 0.001) reflecting the physiological involution. Association of lymphocytes with this DP phenotype was unique to thymoma: 61 of 65 thymomas but none of the other thymic tumors had more than 3% DP cells (frequency of DP cells; thymoma without MG, 59.5 +/- 31.4%; thymoma with MG, 59.4 +/- 22.1%; and other thymic tumors, 0.8 +/- 1.0; mean +/- SD). All the thymic tumors associated with myasthenia gravis were thymomas and had more than 18% DP cells. CONCLUSION. The presence of DP cells in thymomas but not in other tumors suggests that DP cells are induced by the epithelial cells of thymoma. This characteristic may help diagnose thymic tumors; the presence of more than 3% DP cells suggests a thymoma. Also, association of myasthenia gravis suggests a thymoma.     

Choroidal epithelial cyst of the cerebral hemisphere. An immunohistochemical study

A case of choroidal epithelial cyst in the left cerebral hemisphere of a 4-month-old infant is described. The cyst wall was composed of a single epithelial layer with a basement membrane and fibrous connective tissue. An immunohistochemical study revealed the presence of prealbumin in the cytoplasm of these cuboidal epithelial cells. This fact strongly suggested that the cuboidal epithelium lining the cyst wall originated from choroidal epithelial cells. The diagnostic usefulness of the immunohistochemical study in choroidal epithelial cysts is discussed.     

The significance of epithelial differentiation in mixed mesodermal tumors of the uterus. A clinicopathologic and immunohistochemical study

Mixed mesodermal tumors and carcinosarcomas of the uterus are classified as sarcomas. However, in other sites, malignant biphasic tumors may be classified as carcinomas, mesotheliomas, or sarcomas. In order to clarify their behavior and patterns of differentiation, we performed a clinicopathologic and immunohistochemical study of 22 cases aimed at analyzing the pattern of spread and histologic appearance of the metastasis, as well as the distribution of intermediate filaments in the primary tumor and the metastasis. Four monoclonal antibodies (Mabs) were used to detect epithelial lineage, three that recognize keratin (AE1/AE3, CAM5.2, MAK6) and one that recognizes epithelial membrane antigen (EMA). A Mab against vimentin was also used. Metastases involved the omentum, pelvic peritoneum, ovaries, fallopian tubes, pelvic or para-aortic lymph nodes, liver parenchyma, and tonsil. These metastases were composed of carcinoma only. Lymphatic/vascular invasion was identified in 11 cases; it consisted exclusively of carcinoma. In all 12 cases evaluated immunohistochemically, keratin and EMA were identified in the majority of the cells in the epithelial component and in a more focal distribution in the spindle cell component in 11 (92%). Vimentin was detected in the majority of spindle cells in nine cases (75%) and in a more focal distribution in the epithelial component in six cases (50%). In the spindle cell component, keratin and EMA were present in widely scattered individual spindle-shaped and rounded cells, within solid clusters of rounded cells, and in nests of cells with small lumens. The distribution of keratin, EMA, and vimentin in the metastases (carcinoma in all instances) was similar to the epithelial component in the primary tumor. Our findings indicate that the epithelial component of these tumors invades lymphatic/vascular spaces and metastasizes, whereas the spindle cell component has limited metastatic potential, if any. Since the behavior of these neoplasms is dictated by the epithelial element, we believe that mixed mesodermal tumors of the uterus should be classified as carcinomas rather than sarcomas.     

Mucinous tumors of the ovary with argyrophil cells. An immunohistochemical analysis

Forty-five cases of mucinous tumors of the ovary were studied for argyrophilia. Argyrophil cells were identified in seven of the 22 cystadenomas (32%), five of the 11 borderline tumors (45%), and two of the 12 carcinomas (17%). These 14 tumors and two additional mucinous tumors known to contain argyrophil cells were studied further by immunohistochemical methods for the localization of calcitonin, gastrin, somatostatin, adrenocorticotropin (ACTH), serotonin, neurotensin, and lysozyme. Serotonin immuno-reactivity was identified in 15 of the 16 cases. Among the peptide hormones, there was a high frequency of positivity for ACTH, gastrin, and somatostatin. Despite the demonstration of reactivity for these hormones, there was no clinical evidence of syndromes of hormone excess in the patients. Lysozyme was present in all but one of the benign and borderline tumors, but was not identified in the carcinomas. Lysozyme was also found in normal and neoplastic gastric and endocervical epithelium, indicating that its presence is not useful in differentiating gastrointestinal and müllerian-type epithelium. The results of this study confirm the previously recognized intestinal characteristics of the epithelium of many mucinous tumors, but also raise the question whether the simple, uniformly mucinous epithelium that is most common within these tumors and is generally regarded as endocervical in type may occasionally be gastric in nature.     

The distribution of S-100 protein in hyperplastic and neoplastic prostatic epithelium

Specimens from 30 cases of benign prostatichyperplasia and 75 cases of prostatic carcinomaobtained during suprapubic prostatectomy, transurethalresection of the prostate and radical prostatectomy,were stained immunohistochemically for S-100 protein,prostatic acid phosphatase (PAP), prostatic specificantigen (PSA), neuron specific enolase (NSE) andpolyclonal keratin. S-100 protein was positive in9.3% of prostatic carcinomas and negative in allcases of prostatic hyperplasia. PAP and PSA werepositive in all cases, while NSE was positive in 16%of the carcinoma cases. Polyclonal keratin waspositive in both cell layers of the double layeredhyperplastic prostatic epithelium with a more intensestaining pattern in the outer cell layer. The authorsbelieve that the S-100 protein immunoreactivityobserved in some prostatic carcinomas, reflecting thechange in the functional status of the neoplasticcells, might be of prognostic significance. They alsoemphasize the non-myoepithelial nature of the outercell layer of the double layered prostaticepithelium. This revised version was published online in August 2006 with corrections to the Cover Date.     

颈脊髓半切伤综合征后S-100蛋白的分布和变化研究

目的 研究颈髓S-100蛋白分布及半切损伤后S-100蛋白的分布变化及时相改变。探索其与恢复的关系。方法 通过免疫组织化学技术观察大鼠颈脊髓半切伤综合征(Brown-sequard’ssydrone)不同时期神经组织中S-100蛋白的分布变化。结果 在未损伤的颈髓神经中,S-100蛋白分布于雪旺细胞的胞桨和胞膜中。神经切断48小时后,远近节段S-100蛋白反应表达减弱,远端1周后几乎没有S-100的表达,而近段有新生轴索生长时重新表达S-100蛋白。结论 轴索对于雪旺细胞的成熟具有重要作用,S-100蛋白对于轴索的再生具有刺激和诱导作用。S-100蛋白在颈髓不只存在于成熟的雪旺细胞,而且存在于胶质细胞中。S-100蛋白的出现预示着雪旺细胞的成熟和神经再生的表现。     

So-called sclerosing hemangiomas of lung. An immunohistochemical study supporting a respiratory epithelial origin

Sclerosing hemangiomas are benign pulmonary neoplasms. They were initially believed by Liebow and Hubbell to be of endothelial origin; however, subsequent ultrastructural studies have suggested an alveolar pneumocyte and mesothelial derivation. Using a panel of various antibodies on eight cases, the authors found that sclerosing hemangiomas expressed cytokeratin (seven cases), epithelial membrane antigen (seven cases), carcinoembryonic antigen (five cases), vimentin (seven cases), surfactant apoprotein (eight cases), and Clara cell antigen (five cases). These results support the hypothesis that sclerosing hemangiomas represent an epithelial tumor showing simultaneous bronchiolar epithelial and alveolar pneumocyte differentiation.     

Intermediate filamentous proteins in adult granulosa cell tumors. An immunohistochemical study of 25 cases.

Adult granulosa cell tumors (AGCTs) are classified as sex cord-stromal tumors of the ovary. However, they may be confused with other primary ovarian neoplasms. Intermediate filaments, specifically vimentin and cytokeratins, have been identified in AGCTs by immunohistochemistry performed on frozen and formalin-fixed, paraffin-embedded tissue and two-dimensional electrophoresis. Recently, however, immunohistochemical demonstration of cytokeratin has been used as supporting evidence of epithelial rather than sex cord-stromal differentiation in ovarian neoplasia. To investigate further intermediate filamentous proteins in AGCTs, 25 such tumors were studied by immunohistochemistry in formalin-fixed, paraffin-embedded sections. Cytoplasmic staining was observed, frequently in a distinct punctate, paranuclear pattern, in 14 of 25, 14 of 25, and seven of 17 tumors using monoclonal antibodies AE1/AE3, CAM 5.2, and 35BH11, respectively, which share the ability to detect low molecular weight cytokeratins. Staining for cytokeratin was not seen in any of the 17 tumors studied using the antibody 34BE12. Twenty-three of 25 tumors showed strong positivity for vimentin, characteristically seen as globoid paranuclear staining. Nine of 25 tumors contained desmin, which was restricted to the intermixed spindle cell, cortical type stromal component of the tumors. These patterns of immunoreactivity for intermediate filaments, particularly cytokeratins, are different than in common epithelial tumors of the ovary and may be useful in the differential diagnosis of ovarian neoplasia. Moreover, the immunohistochemical detection of cytokeratins should not be used as a criterion for excluding AGCT from the differential diagnosis of an ovarian neoplasm.     

Micronodular thymoma with lymphoid B-cell hyperplasia: clinicopathologic and immunohistochemical study of eighteen cases of a distinctive morphologic variant of thymic epithelial neoplasm.

We describe 18 cases of a distinctive morphologic variant of primary thymic epithelial neoplasm characterized by a micronodular growth pattern associated with florid lymphoid follicular hyperplasia of the stroma. The tumors occurred in seven women and 11 men aged 41 to 76 years (mean, 58 years). All cases were asymptomatic and discovered incidentally on routine chest radiograph or during coronary artery bypass surgery. The tumors measured from 3 to 10 cm in greatest dimension and were well circumscribed and encapsulated. In seven cases, the lesions were grossly described as cystic or partially cystic masses. Histologically, they were characterized by a proliferation of small tumor nodules separated by abundant lymphoid stroma with prominent germinal centers. The nodules were composed of spindle cells containing oval nuclei devoid of atypia or mitotic activity. Immunohistochemical studies showed strong positivity of the spindle tumor cells for CAM 5.2 and broad spectrum keratin antibodies. The surrounding lymphoid cell population was strongly positive for LCA and L26 and showed a polyclonal pattern of staining for kappa and lambda. Stains for UCHL-1, CD1a, CD3, CD5, and CD99 were negative in the stromal lymphoid cell population. The tumor in one of the patients was associated with active pulmonary tuberculosis, and in another with anemia and splenomegaly of unknown etiology. None of the patients had clinical signs or history of myasthenia gravis or other autoimmune disorders. The present cases are interpreted as an unusual morphologic variant of spindle cell thymoma with prominent B-cell lymphoid hyperplasia. The possible significance of this phenomenon is discussed.     

YKL-40 expression in soft-tissue sarcomas and atypical lipomatous tumors: An immunohistochemical study of 49 tumors

Background and purpose

YKL-40 is a glycoprotein that is expressed in many types of cancer cells. In some cancers, there is a correlation between high serum YKL-40 levels on the one hand and more aggressive disease and early death on the other. YKL-40 has never been studied in patients with soft-tissue sarcomas (STSs). We investigated whether YKL-40 is expressed in STS tissue and ascertained that the degree of expression is related to survival and/or the histological grade of the malignancy (FNCLCC).

Patients and methods

We included archived tissue from 49 patients (40 with STS and 9 with atypical lipomatous tumor, 20 female and 29 male, mean age 58 (4–89) years) who were treated with tumor resection in 2004 or 2005 at the Department of Orthopedics, Rigshospitalet. The minimum length of follow-up with respect to survival was 5–7 years. Immunohistochemical analysis with anti-YKL-40 antibody using tissue microarray was performed on resected tumors, and a semiquantitative measure of the intensity of YKL-40 staining was performed.

Results

41 of the 49 tumors were positive for YKL-40, and of these, 36 had moderate to intense staining. 24 of the patients died within the follow-up period, and the intensity of YKL-40 staining was significantly higher in tumors from patients who had died in the follow-up period than in tumors from those who survived (p = 0.01). The staining intensity was different for the 3 grades of malignancy (p = 0.004): it was higher in highly malignant tumors (FNCLCC grade 2 and grade 3) than in low-malignancy tumors (grade 1).

Interpretation

YKL-40 is expressed in soft-tissue sarcomas. There is a correlation between expression of YKL-40 in STS and both histological grade of the malignancy and survival. Whether or not YKL-40 expression is an independent prognostic variable could not be determined in the present study.YKL-40 (also called chitinase 3-like protein 1 (CHI3L1) and human cartilage glycoprotein 39 (HC gp39)) is a 40-kDa heparin-binding glycoprotein (Rehli et al. 1997, Johansen et al. 2009) that is produced by a variety of normal cells and cancer cells (Rehli et al. 1997, Johansen 2006, Johansen et al. 2009). YKL-40 is a growth and differentiation factor—particularly for cartilage cells, bone cells, and fibroblasts (Johansen et al. 2007)—that protects against cell death (Lee et al 2009), and it plays a role in angiogenesis (Shao et al 2009, Faibish et al 2011) and fibrosis (Lee et al 2011). In cancer cells, the production of YKL-40 is stimulated by stress influences such as hypoxia and radiotherapy, and it probably has a role in cancer cell growth, survival, and proliferation (Johansen et al. 2009).Expression of YKL-40 in sarcomas has previously been studied by immunohistochemistry in chondrosarcomas (Daugaard et al. 2009), and improved standardization of the staining method using tissue microarray (TMA) has been used in breast and ovarian cancer tissue (Roslind et al. 2008, Høgdall et al. 2009), but little is known about the expression and prognostic role of YKL-40 in soft-tissue sarcomas (STSs). We therefore investigated the expression of YKL-40 in STS and atypical lipomatous tumors (ALTs) by immunohistochemistry and TMA, and the prognostic significance of the YKL-40 expression was determined.     

胃肠道间质瘤的免疫组化分析及临床诊治

目的 探讨胃肠道间质瘤的诊治、临床病理学及免疫组化特征。方法 收集1998～2005年收治的41例胃肠道间质瘤的临床病理学资料，进行免疫组织化学染色，标记抗体为CD117、CD34、SMA和S-100蛋白。结果 危险程度极低2例，低度危险8例，中度危险19例，高度危险12例。肿瘤是否浸润黏膜肌层或浆膜层与危险程度相关（χ^2=4．85，P＜0．05）CD117、CD34、SMA和S-100蛋白阳性表达分别为90％、83％、37％和25％，其阳性表达率与肿瘤危险程度无关（χ^2=0．34、0．04、0．01、0．02，P＞0．05）。结论 Fletcher的危险程度分类符合临床治疗与预后的需要。肿瘤浸润黏膜肌层或浆膜层是危险性的重要指标，而免疫表型与危险程度无关。肿瘤完全切除联合使用伊马替尼是改善预后的关键。     

Clinical and functional significance of WHO classification on human thymic epithelial neoplasms: a study of 146 consecutive tumors

We examined the clinical and functional significance of histologic classification of thymic epithelial neoplasms proposed by the World Health Organization (WHO), based on an analysis of 146 consecutive tumors derived from 141 patients and 47 normal thymuses derived from children ranging in age from 1 to 9 years. Invasive tumors were seen in 12.5%, 38.6%, 40.0%, 69.4%, 80.0%, and 100% of type A, AB, B1, B2, B3, and C primary tumors, respectively. All of six recurrent or metastatic lesions were type B2 tumors. Myasthenia gravis was associated in 0%, 6.8%, 40.0%, 55.6%, 10.0%, and 0% in patients with type A, AB, B1, B2, B3, and C tumors, respectively. The average number (x10(6)) of tumor-associated CD4+CD8+ cells present in 1 g of tumor tissue was 1.5, 391.1, 1041.7, 333.9, 24.5, and 0.2 in type A, AB, B1, B2, B3, and C, respectively, and it was 1168.2 in the normal thymuses. Thus, type B1 tumor retained the function to induce CD4+CD8+ double-positive cells at a level comparable to that of the normal thymic cortical epithelial cells, followed by type AB and type B2 tumors. Type A and B3 tumors had this function at a barely detectable level, and type C tumor was nonfunctional. WHO histologic classification was shown to reflect the clinical features and the T-cell-inducing function of thymic epithelial tumors.