Smooth muscle neoplasms of the urinary bladder: a clinicopathologic comparison of leiomyoma and leiomyosarcoma

We report the clinicopathologic, immunohistochemical, and DNA ploidy findings of 18 leiomyosarcomas of the urinary bladder. In addition, we compare these malignant smooth muscle tumors with 10 cases of urinary bladder leiomyoma. The 14 male and four female patients with leiomyosarcoma ranged in age from 25 to 88 years (mean 64 years). The tumors ranged from 3.0 to 15.0 cm (mean 7.1 cm) in greatest dimension and were moderately to highly cellular, consisting of interlacing fascicles of spindled cells with mild to marked nuclear atypia. Coagulative tumor necrosis was identified in 14 cases (78%), and mitotic activity ranged from 1 to 42 mitotic figures (MF) per 10 high power fields (HPF) (mean 12 MF/10 HPF). Tumors were classified as either high-grade (12 cases) or low-grade (six cases) based on nuclear atypia, mitotic activity, and tumor necrosis. Actin positivity was present in 15 tumors (83%), and desmin immunoreactivity was present in seven tumors (39%). All cases were negative for epithelial markers and S-100. Proliferative activity, as assessed by MIB-1 staining, ranged from 0.1% to 51.4% (median 9.1%). Seven (39%) of the leiomyosarcomas were DNA aneuploid, eight (44%) were tetraploid, and three (17%) were diploid. Five patients underwent radical cystoprostatectomy, one radical cystectomy, seven had partial cystectomy, two underwent pelvic exenteration, and three patients had transurethral resection only. Follow-up information was available on all 18 cases and ranged from 2 to 68 months (mean 22 months). Of the 12 patients with high-grade tumors, six (50%) died of disease from 2 to 20 months (mean 7 months) after diagnosis and three patients (25%) are alive with metastatic tumor. Two of the six patients with low-grade leiomyosarcoma died of tumor, 61 and 68 months after diagnosis. There were five male and five female patients with leiomyoma ranging in age from 22 to 78 years (mean 61 years). The tumors ranged from 0.5 to 4.5 cm (mean 1.6 cm) in greatest dimension, were well circumscribed, and had low cellularity. Mitotic activity, necrosis, and cellular atypia were absent, and the tumors were strongly positive for both actin and desmin. MIB-1 staining ranged from 0% to 3.8% (median 0.8%). Seven (87.5%) of the leiomyomas were DNA diploid or near-diploid and one (12.5%) was DNA aneuploid. Six patients were treated with transurethral resection and four with partial cystectomy. All 10 patients were alive at the last follow-up (mean follow-up 75 months), and no tumor recurred or metastasized. Our study shows that low-grade leiomyosarcomas are capable of malignant behavior, and high-grade leiomyosarcomas appear to behave more aggressively than low-grade tumors. In addition, the diagnosis of urinary bladder leiomyoma should be reserved for noninfiltrative smooth muscle tumors lacking mitotic activity, cytologic atypia, and necrosis.     

Pleomorphic fibroma of the skin: a benign neoplasm with cytologic atypia. A clinicopathologic study of eight cases

A clinicopathologic study of eight examples of polypoid and dome-shaped cutaneous fibrous lesions with sparse cellularity but striking nuclear atypia and rare mitotic figures is presented. Positive immunohistochemical staining for vimentin and actin supported the fibroblastic nature of these lesions. All eight cases were adults whose ages ranged from 33 to 67 years (mean 52 years). Five were women and three were men. Five lesions were located on extremities, two on the trunk, and one on the face and they measured from 4 to 16 mm in greatest dimension. The lesions were clinically followed from 4 months to 5 years. They all showed benign clinical behavior, with only one local recurrence in a lesion that had been incompletely removed. The nuclear atypia seen in these fibrous lesions may be similar to that which occurs in other benign mesenchymal neoplasms, such as pleomorphic lipoma, pleomorphic leiomyoma, ancient schwannoma, and variants of dermatofibroma with atypical cells. We suggest that "pleomorphic fibroma" is an appropriate term for this lesion based on its histologic differentiation, cytologic atypia, and benign clinical course.     

Primary uterine endometrial stromal neoplasms. A clinicopathologic study of 117 cases

We present the results of a clinicopathologic study of 109 patients with endometrial stromal sarcoma and eight patients with endometrial stromal nodule. Of the 109 patients with endometrial stromal sarcoma, follow-up was obtained on 93 (85%). The stage distribution of the patients with stromal sarcoma and the number of patients with follow-up (numerator) compared to the total number of patients in each stage (denominator) are: Stage 1, 73/85; Stage II, 3/6; Stage III, 11/11; Stage IV, 6/7. Stage II patients are considered separately in the analysis. Thirty-six percent of the Stage I patients experienced one or more relapses. Of these, six (23%) died of disease from 11 to 360 months from diagnosis (median, 79 months). Nine (35%) were alive with disease. Of the eleven Stage III patients, eight had one or more relapses and of these, six died of disease. Of the six Stage IV patients, five had one or more relapses and of these, three died of disease. The outcome differences between Stages I, III, and IV are statistically significant (p less than .01). Microscopic features evaluated included the mitotic index (MI = number of mitoses/10 high-power fields) and cytologic atypia. Forty-five percent of Stage I patients who had both rare mitotic figures and minimal atypia had one or more relapses and of these, two (13%) died of disease at 85 and 360 months, respectively. Thus, neither MI nor cytologic atypia were predictive of tumor recurrence for patients with Stage I tumors.     

Synovial sarcoma--identification of favorable and unfavorable histologic types: a Scandinavian sarcoma group study of 104 cases

Synovial sarcoma has traditionally been regarded as a high-grade sarcoma and treated as such. Recently, specific types of poorly differentiated synovial sarcoma have been defined and shown to affect prognosis adversely. We studied 104 primary synovial sarcomas of the extremities and trunk wall without metastasis at diagnosis that were retrieved from the Scandinavian Sarcoma Group Registry (SSG) and the Swedish Cancer Registry from 1986 to 1994. Follow-up was available in all patients, median 6 (3-11) years for the survivors. There were local recurrences in 15% of patients and metastases in 33%. Histologically, the tumors were divided into favorable and unfavorable types. The favorable type had no significant cytologic atypia, and in most instances, no necrosis and a mitotic count of < 10/10 hpf. The unfavorable type included so-called poorly differentiated synovial sarcomas as well as recognizable biphasic and monophasic synovial sarcomas with prominent nuclear atypia, extreme cellularity and nuclear crowding. Designation of a tumor as having favorable vs. unfavorable histology conveyed more prognostic information than any single histologic factor. Kaplan-Meier estimates of metastasis-free survival at 5 years were 83% for patients with histologically favorable tumors and 31% for patients with histologically unfavorable tumors (95% confidence intervals 72-92% and 13-51%, respectively). These findings may influence future treatment protocols for synovial sarcoma.     

Lymphoid infiltrates of the stomach. Evaluation of histologic criteria for the diagnosis of low-grade gastric lymphoma on endoscopic biopsy specimens

Low-grade gastric lymphomas may be difficult to distinguish from benign inflammatory infiltrates on endoscopic biopsy specimens. Recent reports have suggested that so-called lymphoepithelial lesions (infiltration of lymphocytes into glandular epithelium) are characteristic of primary gastric lymphomas. We evaluated the presence and prominence of lymphoepithelial lesions and other histologic criteria in 25 low-grade gastric lymphomas (21 primary) and 58 benign inflammatory infiltrates to evaluate their utility in distinguishing benign from malignant gastric lymphoid infiltrates. The following features were associated only with lymphomas: (a) prominent (2-3 +) lymphoepithelial lesions (eight of 24 versus none of 58; p less than .0001); (b) Dutcher bodies (three of 25 versus none of 58, p = .05); and (c) moderate cytologic atypia (nine of 25 versus none of 58, p less than .0001). One or more of these features was seen in 18 of 25 gastric lymphomas (72%). Features more often associated with, but not limited to, lymphomas were dense (2-3 +) lymphoid infiltrates (25 of 25 versus five of 58, p less than .0001), rare or questionable lymphoepithelial lesions (11 of 24 versus 17 of 58, p = .01), muscularis mucosae invasion (20 of 20 versus 20 of 47, p less than .0001), ulceration (12 of 24 versus five of 58, p less than .0001), and mild cytologic atypia (eight of 25 versus six of 58, p less than .005). Germinal centers, crypt abscesses, and reactive epithelial atypia were seen with equal frequency in both types of infiltrate. Acute inflammation (2-3 +) was associated more often with inflammatory infiltrates (two of 25 versus 27 of 58, p less than .001). Our results suggest that dense lymphoid infiltrates with either prominent lymphoepithelial lesions, moderate cytologic atypia, or Dutcher bodies are highly suggestive and may be diagnostic of lymphoma. This constellation of findings is present in about 70% of endoscopic biopsy specimens of low-grade gastric lymphoma. In addition, the majority of cases of primary low-grade gastric lymphoma have morphologic, immunophenotypic, and clinical features that justify their inclusion in the category of low-grade lymphomas of mucosa-associated lymphoid tissue, whereas a minority are examples of lymphomatous polyposis of the gastrointestinal tract (centrocytic lymphoma).     

Smooth muscle tumors of the ovary: a clinicopathologic study of 54 cases emphasizing prognostic criteria, histologic variants, and differential diagnosis

We studied 54 ovarian smooth muscle tumors with an emphasis on histologic criteria for malignancy. Twenty-two leiomyomas were identified, including 7 typical, 11 cellular, 2 mitotically active, 1 with bizarre nuclei, and 1 myxoid. Follow-up ranging from 12 to 240 months (mean, 77.6 months) was available for 14 patients; all were alive with no evidence of disease. Of 26 leiomyosarcomas, including 2 myxoid leiomyosarcomas, most were readily diagnosed by the presence of at least two of the following: moderate or severe cytologic atypia, mitotic rate > or =10 mitotic figures per 10 high power fields, and tumor cell necrosis. Some cytologically atypical tumors demonstrated lesser mitotic activity of 5 to 9 mitotic figures per 10 high power fields, in the absence of tumor cell necrosis. Sixty percent of these were clinically malignant, supporting a diagnosis of leiomyosarcoma in such tumors. Follow-up was available for 21 patients. Seventy-one percent developed recurrent disease at a mean of 19 months, and 62% died of their disease at a mean of 24 months. Four tumors were deemed of uncertain malignant potential, and two that were stage II both recurred in the pelvis. One case of ovarian intravenous leiomyomatosis had a benign outcome at 42 months, as did one case of ovarian leiomyoma with leiomyomatosis peritonealis disseminata at 180 months. Overall, ovarian smooth muscle tumors encompass the same varied histologic spectrum as their uterine counterparts. The main tumors in the differential diagnosis are those in the fibroma/thecoma category, spindle cell carcinomas, and metastatic gastrointestinal stromal tumors.     

Genomic analysis of blue nevi and related dermal melanocytic proliferations

Blue nevi are benign dermal melanocytic proliferations that can sometimes share overlapping microscopic features with melanoma. We used comparative genomic hybridization to analyze three groups of dermal melanocytic proliferations. Group 1 consisted of 10 cellular blue nevi and 1 deep penetrating nevus, none of which showed chromosomal aberrations. Group 2 consisted of 11 lesions that were histopathologically ambiguous. Three of these lesions demonstrated chromosomal aberrations (three or fewer per lesion). Group 3 consisted of seven histopathologically malignant lesions, each showing three or more chromosomal aberrations. Moderate to severe cytologic atypia and a mitotic rate of three or more mitoses per 10 high power fields were present in six of eight (75%) lesions that had at least three chromosomal aberrations but were absent in 15 of 20 (75%) lesions without chromosomal aberrations. Necrosis was present in four of the 29 (13%) lesions, with every lesion with necrosis demonstrating three or more genomic abnormalities. In conclusion, histopathologically unequivocally benign or malignant dermal melanocytic proliferations show nonoverlapping patterns of chromosomal aberrations. Ambiguous lesions can be separated into lesions with and without chromosomal aberrations. Future studies with clinical follow-up are necessary to determine which aberrations are most informative for classification of these lesions.     

Composite intestinal adenoma-microcarcinoid

Composite intestinal adenoma and microcarcinoid is a rare intestinal neoplasm consisting of intermingled adenomatous and well-differentiated neuroendocrine components. A few case reports and small series have suggested an indolent clinical course for this entity. We reported 7 cases of composite intestinal adenoma-microcarcinoid, including their morphologic features and clinical follow-up, both in biopsy and resection specimens. We identified 7 cases of composite intestinal adenoma-microcarcinoid from our pathology database. Five were from the large intestine, and 2 were in the duodenum. Morphologically, all microcarcinoids exhibited low-grade cytologic atypia and were devoid of significant pleomorphism, necrosis, and mitotic activity. Among the 7 lesions, 6 had a lobular architecture with smooth borders and mucosa-confined microcarcinoids; none had neuroendocrine carcinoma in subsequent resections. However, 1 colonic case had carcinoid cells penetrating the muscularis mucosae into the submucosa with an infiltrative border, and the resection showed metastatic high-grade neuroendocrine carcinoma in 1 lymph node. Composite intestinal adenoma-microcarcinoid is extremely rare. Although composite mucosa-confined adenoma-microcarcinoid is likely to have an indolent behavior, submucosal invasion by the neuroendocrine component may be associated with aggressive behavior.     

A recurrent solitary fibrous tumor of the thigh with malignant transformation: A case report

IntroductionWe describe an unusual case of a uniformly high-grade malignant solitary fibrous tumor (SFT) of the thigh with recurrence after wide resection in a 31-year-old man.Presentation of caseOur current case showed a long-term benign course before the operation, although the subcutaneous tumor was larger than 10 cm at presentation. The SFT was diagnosed by needle biopsy, and wide resection was performed. Histological findings showed proliferation of capillaries surrounded by masses of spindle-shaped cells without any cytologic atypia, and the percentage of MIB-1-positive nuclei was 2.1%. However, a rapidly enlarging recurrent tumor was observed 11 months after the operation. A second wide resection for the recurrent tumor was performed. Histologically, the tumor cells uniformly displayed significant cytologic atypia and pleomorphism, and had 40–50 mitoses per 10 high-power fields. The proportion of MIB-1-positive nuclei was 48%. Consequently, the tumor was diagnosed as a SFT with malignant transformation.DiscussionThe malignant transformation described in past studies showed high-grade areas within benign, low-grade, or intermediate-grade SFTs. Therefore, in contrast to our case, uniformly high-grade malignant histological findings at recurrence were not described.ConclusionEven if a tumor is non-malignant during the clinical course, as confirmed by tissue biopsy, the possibility of tumor progression to high-grade sarcoma at recurrence should be considered, and the treatment strategy should be determined carefully.     

Grading ovarian serous carcinoma using a two-tier system

In this study, we evaluate a two-tier system for grading ovarian serous carcinoma. This system is based primarily on the assessment of nuclear atypia with the mitotic rate used as a secondary feature. The study included 50 cases of low-grade ovarian serous carcinoma and 50 cases of high-grade ovarian serous carcinoma retrieved from the files of the Department of Pathology at the University of Texas M. D. Anderson Cancer Center from a 28-year period. Cases assigned to the low-grade category were characterized by the presence of mild to moderate nuclear atypia. As a secondary feature, they tended to show up to 12 mitoses per 10 high power fields (HPFs), whereas those in the high-grade category had marked nuclear atypia and as a secondary feature more than 12 mitoses per 10 HPFs. For comparison, the tumors were also graded using the Shimizu/Silverberg and the FIGO grading systems. Patients in the low-grade ovarian serous carcinoma group ranged in age from 19 to 75 years (mean 41.7 years) while patients in the high-grade ovarian serous carcinoma group ranged in age from 27 to 76 years (mean 55 years). All of the cases except one were advanced FIGO stage. Using the Shimizu/Silverberg system, the low-grade ovarian serous carcinoma cases were distributed as follows: grade 1, 47 cases; grade 2, 3 cases. Using the FIGO grading system, 35 cases were grade 1 and 15 cases were grade 2. Regarding the high-grade ovarian serous carcinoma group using the Shimizu/Silverberg system, 14 of the cases were grade 2 and 36 cases were grade 3. Using the FIGO grading system, 1 case was grade 1, 38 cases were grade 2, and 11 cases were grade 3. Most of the patients in both groups were treated with total abdominal hysterectomy and bilateral salpingo-oophorectomy and also received cisplatinum-based chemotherapy. On follow-up, 37 patients in the low-grade ovarian serous carcinoma group had died of disease at a median 4.2 years after diagnosis compared with 46 patients in the high-grade ovarian serous carcinoma group who died of disease at a median of 1.7 years. Eight patients in the low-grade ovarian serous carcinoma group and 4 patients in the high-grade ovarian serous carcinoma group were alive with disease at median follow-ups of 4.3 and 3.85 years, respectively. Four patients with low-grade serous carcinoma were alive without evidence of disease after a follow-up that ranged from 4.4 to 22.6 years (median 6.85 years), and one died of other causes 14 years after the diagnosis of her ovarian tumor. On multivariate analysis, residual tumor and tumor grade based on the M. D. Anderson two-tier system for grading ovarian serous carcinoma were found to be significant independent prognostic factors (P = 0.003 and 0.04, respectively). Of interest, 60% of the low-grade ovarian serous carcinomas in this study were associated with a serous neoplasm of low malignant potential, whereas this association was present in only 2% of the high-grade ovarian serous carcinomas. This finding could reflect a difference in the pathogenesis of ovarian serous carcinomas of different grades. In summary, there is usually a good correlation between the two-tier grading system herein presented and the Shimizu/Silverberg and the FIGO grading systems. Because this system is based on defined criteria that are easy to follow and because it involves only two diagnostic categories, it should provide better reproducibility in the grading of ovarian serous carcinoma. However, additional studies are required to validate these statements.     

Prognostically favorable "mitotically active" smooth-muscle tumors of the uterus. A clinicopathologic study of ten cases

We evaluated the clinicopathologic features of 22 smooth-muscle tumors of the uterine corpus that had at least five mitoses per 10 high-power fields (HPF) in the most active areas. Ten women were alive and well without tumor recurrence 15 months to 11 years after diagnosis (median, 6 years); these patients were referred to as the "clinically benign" group. The other 12 women had "clinically malignant" disease: 9 died of recurrent or metastatic tumor 3 months to 4.5 years after diagnosis (median, 16 months), and 3 are alive with disease 4-12 months after diagnosis. Significant clinical and pathologic differences were observed between patients in the "benign" and "malignant" groups. We found that mitotic activity in the range of 5 to 15 mitoses per 10 HPF was not a reliable predictor of aggressive behavior in tumors that lacked marked cytologic atypia and that by all other clinical and pathologic criteria were leiomyomas. An unfavorable prognosis among the mitotically active neoplasms could be predicted by a constellation of clinicopathologic features, including postmenopausal status, a clinical or intraoperative impression of cancer by the surgeon, extension of tumor beyond the uterine corpus, size greater than 10 cm, marked cytologic atypia, invasive borders, necrosis, and mitotic counts exceeding 20 per 10 HPF.     

Fibromatosis of the breast. A clinical and pathological study of 28 cases

The clinical and pathologic findings of 28 examples of fibromatosis of the breast not involving the deep fascia or chest wall are reported. Five of the 20 lesions treated by local excision recurred. Recurrences developed within a 4 to 8 month period following surgery in four of the five instances, and 6 years after surgery in one instance. One lesion recurred five times over a period of 3 years. None of the patients died from their disease, and none developed a metastasis. Those lesions that recurred had been inadequately excised initially, since surgical margins showed fibromatosis. Specific histological features, such as size, cellularity, atypia, and mitotic figures, were not helpful in predicting recurrence. Although local excision appears to have been adequate in the majority (75%) of the patients, the infiltrative nature of fibromatosis necessitates documentation of tissue margins in order to avoid the possibility of recurrence. The differential diagnosis includes benign reactive processes (such as keloid and nodular fasciitis), fibrous histiocytoma, low-grade spindle-cell (metaplastic) carcinoma, and fibrosarcoma.     

Cellular fibromas of the ovary: a study of 75 cases including 40 mitotically active tumors emphasizing their distinction from fibrosarcoma

Cellular fibroblastic tumors of the ovary are currently classified as either cellular fibroma (CF) or fibrosarcoma. The former are characterized by bland nuclei, 3 or fewer mitotic figures per 10 high-power fields (MFs/10 HPFs), and a low malignant potential, whereas fibrosarcomas usually have severe nuclear atypia, > or = 4 MFs/10 HPFs, and an aggressive clinical course. The prognosis of cellular fibromatous tumors with > or = 4 MFs/10 HPFs and low-grade cytology is not established and it is the purpose of this study to investigate that aspect. It has been our anecdotal experience that otherwise typical CFs with > or = 4 MFs/10 HPFs usually have a benign clinical course, suggesting that such tumors should be regarded as "mitotically active cellular fibroma" (MACF) rather than fibrosarcoma. Seventy-five cellular fibromatous neoplasms were analyzed to determine their clinicopathologic features and the appropriateness of "MACF" as a designation for otherwise typical CFs with > or = 4 MFs/10 HPFs. The mean age of patients with CF (n = 35, 0 to 3 MFs/10 HPFs) and MACF (n = 40, > or = 4 MFs/10 HPFs) was 51 and 41 years, respectively. Patients most commonly presented with symptoms related to a pelvic mass. All tumors were unilateral. The mean tumor size of CFs was 8.0 cm and 9.4 cm for MACFs. The majority of the tumors were solid; approximately one-third of them had a cystic component. Ovarian surface adhesions, involvement of the ovarian surface, or both, was present in 6% of CFs and 10% of MACFs. Eleven percent of CFs and 13% of MACFs were associated with extraovarian involvement. All tumors consisted of cellular, intersecting bundles of spindle cells with bland nuclear features. The mean highest mitotic count for MACFs was 6.7 MFs/10 HPFs (range 4 to 19 MFs/10 HPFs). Follow-up of 3 months to 12 years (mean 4.75 y) was available in 18 of the 40 patients with MACFs and was uneventful in all cases. We conclude that cellular fibromatous neoplasms with bland cytology and elevated mitotic counts are associated with favorable patient outcome and should be diagnosed as MACF rather than fibrosarcoma, which usually have moderate to severe atypia and elevated mitotic rates. As prior observations have shown that even typical CFs can occasionally recur locally, particularly if they are associated with rupture or adherence, long-term follow-up for patients with CFs and MACFs is appropriate.     

Appendiceal mucinous neoplasms: a clinicopathologic analysis of 107 cases

The classification of appendiceal mucinous tumors is controversial and terminology used for them inconsistent, particularly when they lack overtly malignant features but are associated with extra-appendiceal spread. We reviewed 107 appendiceal mucinous neoplasms and classified them as low-grade appendiceal mucinous neoplasm (LAMN) (n = 88), mucinous adenocarcinomas (MACAs) (n = 16), or discordant (n = 3) based on architectural and cytologic features. LAMNs were characterized by a villous or flat proliferation of mucinous epithelium with low-grade atypia. Thirty-nine tumors were confined to the appendix, but 49 had extra-appendiceal tumor spread, including 39 with peritoneal tumor characterized by mucin pools harboring low-grade mucinous epithelium, usually dissecting in a hyalinized stroma. Eight of the 16 MACAs lacked destructive invasion of the appendiceal wall and eight showed an infiltrative pattern of invasion. Extra-appendiceal tumor spread was present in 12 MACAs (four peritoneum, seven peritoneum and ovaries; one ovaries only). In MACAs with an infiltrative pattern, peritoneal tumor consisted of glands and single cells in a desmoplastic stroma. The peritoneal tumor in the remaining cases consisted of mucin pools that contained mucinous epithelium with high-grade atypia and, in some cases, increased cellularity compared with that seen in peritoneal spread in cases of LAMN. Three cases were classified as discordant because the appendiceal tumors were LAMNs but the peritoneal tumors were high-grade. Follow-up was available for 49 LAMNs, 15 MACAs, and 2 discordant cases. None of the patients with LAMNs confined to the appendix experienced recurrence (median follow-up 6 years). LAMNs with extra-appendiceal spread were associated with 3-, 5-, and 10-year survival rates of 100%, 86%, and 45%, respectively. Patients with MACA had 3- and 5-year survival rates of 90% and 44%, respectively (p = 0.04). The bulk of peritoneal disease correlated with prognosis among patients with MACA (p = 0.04) and, to a lesser degree, among patients with LAMNs (p = 0.07). We conclude that: 1) appendiceal mucinous neoplasms can be classified as either low-grade mucinous neoplasms or mucinous adenocarcinoma based on architectural and cytologic features; 2) tumors that can be confidently placed in the low-grade group (which requires rigorous pathologic evaluation of the appendix) and are confined to the appendix are clinically benign in our experience to date; 3) low-grade tumors confined to the appendix are morphologically identical to those with extra-appendiceal spread (except for the usual identification of breach of the wall in the latter cases) and the same designation is appropriate for the appendiceal neoplasia in each situation; 4) the long-term outlook for patients with low-grade tumors and peritoneal spread is guarded with just over half dying of disease after 10 years; 5) appendiceal mucinous tumors with destructive invasion of the appendiceal wall, complex epithelial proliferations, or high-grade nuclear atypia generally pursue an aggressive clinical course and should be classified as mucinous adenocarcinomas; 6) peritoneal tumor can be classified as involvement by LAMN or MACA, and this distinction is of prognostic significance; 7) bulky peritoneal tumor worsens prognosis; and 8) LAMNs associated with high-grade peritoneal tumor behave as adenocarcinoma.     

Mucinous adenofibromas of the ovary. A report of 10 cases

Mucinous epithelium is the most uncommon type identified in ovarian adenofibromas. Because of the rarity of mucinous adenofibromas and the presence of cytologic atypia in some, these neoplasms may be mistaken for low-grade metastatic adenocarcinoma. The clinicopathologic features of 10 mucinous adenofibromas are reviewed. They occurred in women 24 to 76 (mean, 51) years of age, were unilateral, and ranged in diameter from 1 to 25 cm. Seven tumors were classified as benign, containing glands lined by a single layer of mucin-containing columnar cells. Three tumors that contained crowded glands lined by mucin-containing cells with mild to moderate nuclear atypia, nuclear stratification of up to three cells in thickness, and focal tufting were classified as benign with epithelial atypia. Most women had a hysterectomy and bilateral salpingo-oophorectomy. Follow-up information was available on six women, who were alive and well from 6 to 126 (mean 41) months after diagnosis. The identification of mucinous glands in typical fibromatous stroma should allow the distinction of these benign neoplasms from metastatic carcinomas.     

Primary pulmonary malignant meningioma.

Fewer than 20 cases of primary pulmonary meningioma have been reported. Most of these cases have been histologically and clinically benign. We report an unusual case of primary pulmonary malignant meningioma with atypical histologic features and malignant behavior. A computed tomography scan of the head did not show evidence of tumor. The right upper lobe mass was resected and showed features of an atypical meningioma with loss of architectural pattern, mild nuclear pleomorphism, increased mitotic counts (up to 15 mitotic figures per 10 high power fields), and focally prominent nucleoli. Focally, cells with rhabdoid features were identified. The tumor's immunohistochemical and ultrastructural profiles were consistent with a meningioma. The tumor stained negative for estrogen and focally positive for progesterone receptors and had a MIB-1 labeling index (marker of cell proliferation) of 9.2%. Approximately 5 months after the initial resection, the patient experienced a tumor recurrence with multiple lymph node metastases, spread to the middle and lower lobes of the right lung, and metastasis to the diaphragm. Rarely, primary pulmonary meningiomas may present as high-grade malignant lesions.     

Multinucleated giant cells in plantar fibromatosis.

Specimens from 13 patients with plantar fibromatosis were reviewed with particular attention to the presence and number of multinucleated giant cells in the lesions. These were found in all specimens but one and ranged from very few to many. The nuclei of the giant cells were uniform, rounded to somewhat elongated, and arranged in circles, semicircles, ovals, clusters, chains, and V's. Aside from the giant cells, the lesions were composed of the usual uniform fibroblastic spindle cells. The growth pattern was almost always multinodular, with nodules having moderate to high cellularity. Maximal mitotic rate varied up to more than 10 mitotic figures per 10 high-power fields but was most often between 1 and 4 mitotic figures per 10 high-power fields. The patients were from 10 to 66 years of age; nine were male and four were female. Two had bilateral involvement. Five patients had recurrence, including three with multiple recurrences, and all but one of the remainder had only short follow-up. Judging from the available data, recurrence did not appear to be related to any specific clinical or pathologic feature.     

Localized benign and malignant fibrous tumors of the pleura. A clinicopathologic review of 223 cases

We reviewed 223 localized fibrous tumors of the pleura and divided them histologically into 141 benign and 82 malignant neoplasms. The criteria used for a judgement of malignancy were high cellularity and mitotic activity (more than four mitotic figures per 10 high-power fields), pleomorphism, hemorrhage, and necrosis. The tumors occurred equally in both sexes, most commonly in the sixth to seventh decades of life. Presenting symptoms included chest pain, dyspnea, and cough; they were observed in three-fourths of patients with a malignant tumor. One in every four of these patients had hypoglycemia, clubbed digits, or pleural effusion. Two-thirds of the tumors were attached to visceral pleura, often by a pedicle. The rest arose from the parietal pleura of the chest wall, diaphragm, or mediastinum. Neoplasms in these atypical sites, together with fissural lesions and tumors "inverted" into peripheral lung, were more often malignant. Most neoplasms measured 5-10 cm and weighed 100-400 g. Microscopically, the "patternless pattern," or hemangiopericytic type, was seen in the majority of cases, and mixed patterns were seen in nearly 40% of tumors. Of the 169 tumors where follow-up was available, all of the benign and 45% of the malignant tumors were cured by simple excision. Patients surgically cured of a malignant neoplasm had pedunculated or well-circumscribed lesions. However, 55% of patients with malignant tumors succumbed to their disease secondary to invasion, recurrence, or metastasis. Resectability is the single most important indicator of clinical outcome. No tumor expressed epithelial differentiation, either immunohistochemically or ultrastructurally; therefore, we favor the term "localized fibrous tumor" of pleura instead of "localized mesothelioma."     

Cutaneous Leiomyoma with Cytologic Atypia, Akin to Uterine Symplastic Leiomyoma

BACKGROUND: Smooth muscle tumors of the skin with cytologic pleomorphism and mitotic activity have traditionally been characterized as leiomyosarcomas, despite having a benign clinical course. In the uterus, there is a smooth muscle tumor known as symplastic leiomyoma, which typically has cytologic pleomorphism without significant mitotic activity. OBJECTIVE: The objective was to illustrate by case report the unusual histologic variant of the cutaneous pilar leiomyoma analogous to the symplastic leiomyoma of the uterus. METHODS: A 54-year-old woman presented with a clinical picture of cutaneous leiomyoma but had histologic features of nuclear hyperchromasia and pleomorphism, but rare mitoses. RESULTS: Management of this patient included excision of the involved area. CONCLUSION: Symplastic leiomyoma is an atypical uterine leiomyoma with cytologic atypia. We present the case of a patient with cutaneous leiomyomas that histologically demonstrated similar features to a uterine symplastic leiomyoma. We believe that this represents a distinct histologic variant of the cutaneous pilar leiomyoma analogous to the symplastic leiomyoma of the uterus.