The Spectrum of Morphologic Alterations Associated With Infarction in Endometrial Polyps: A Report of 41 Cases.

The authors describe the clinicopathologic features of a group of endometrial polyps that exhibited large areas of infarction, to highlight the spectrum of morphologic alterations that may occur in this setting, including moderate cytologic atypia in a subset. Forty-one infarcted endometrial polyps, classified as such based on the presence therein of confluent zones of stromal necrosis and/or sharply demarcated zones of paucicellular to acellular stromal hyalinization, were assembled from multiple institutions. All were diagnosed in biopsies, polypectomies, or curettages. The morphologic profile of the epithelium associated with the infarcted zones was compared with those of a control group of 40 consecutive noninfarcted polyps. The patients with infarcted polyps ranged in age from 23 to 94 yr and were significantly older than the control group patients (mean ages, 60.8 vs. 49 yr respectively; P=0.02). The most common architectural alteration in infarcted polyps was a distinctive cellular tufting or pseudopapillary change, possibly representing an exuberant iteration of papillary syncytial change, which was seen in 39% of cases. Among the features that were significantly more prevalent in infarcted polyps than the control group were grade 2 pleomorphism (i.e., a 2-3-fold variation in nuclear size and/or shape) (37% vs. 2.5%, respectively; P=0.00029), cellular syncytia (44% vs. 15%; P=0.069), vesicular chromatin greater than background glands (56% vs. 7.5%; P <0.0001), hobnail cells (27% vs. 0%; P=0.0004), clear cells (12% vs. 0%; P=0.055), and eosinophilic cells (56% vs. 15%; P=0.000115). The 2 groups were not significantly different regarding mitotic index and a variety of other morphologic variables. Irrespective of morphology, epithelia within the infarcted zones at least focally showed a core immunophenotype (p53-wild type, p16-diffusely positive; low proliferative index) that was essentially identical to the phenotype displayed by foci of papillary syncytial metaplasia unassociated with polyps in a 10-case comparison group. None of the 34 patients with follow-up information has subsequently been diagnosed with a uterine neoplasm. In summary, infarcted endometrial polyps frequently display a spectrum of cytoarchitecturally atypical epithelial changes. These pseudoneoplastic alterations are most likely degenerative and/or metaplastic in nature.

Does the Loss of ARID1A (BAF-250a) Expression in Endometrial Clear Cell Carcinomas Have Any Clinicopathologic Significance? A Pilot Assessment.

SWI/SNF chromatin-modification complexes use the energy of ATP hydrolysis to remodel nucleosomes and to affect transcription and several cellular processes. Accordingly, their loss of function has been associated with malignant transformation. ARID1A (the expression of whose product, BAF250a, a key complex component, is lost when mutated) has recently been identified as a tumor suppressor gene that is mutated in 46-57% of ovarian clear cell carcinoma (CCC). The purposes of this study are to assess the frequency of loss of BAF250a expression in endometrial CCC and whether this loss has any discernable clinicopathologic implications. 34 endometrial carcinomas with a CCC component (including 22 pure CCC, 8 mixed carcinomas with a 10% CCC component, and 4 carcinosarcomas with a CCC epithelial component), were evaluated by immunohistochemistry using a monoclonal antibody directed against the human BAF250a protein. 5 (22.7%) of the 22 pure CCC were entirely BAF250a negative, whereas the remainder showed diffuse immunoreactivity. None of 4 carcinosarcomas and only 1 (12.5%) of the 8 mixed carcinomas were BAF250a negative. There was no discernable relationship between BAF250a immunoreactivity status and tumor architectural patterns (solid, papillary or tubulocystic areas) or cell type (flat, hobnail or polygonal). Of the 22 patients with pure CCC, 14, 2, 3, and 3 were International Federation of Gynecology and Obstetrics stages 1, II, III and IV respectively. Interestingly, all 5 BAF250a negative cases were late stage [stages III or IV] as compared with 1 of 17 BAF250a positive cases (p=0.0002). Thus, 83% (5/6) of all late stage cases were BAF250a [-], as compared with 0 (0%) of the 16 early stage (I or II) cases (p=.0002). BAF250a negative and positive cases did not show any statistically significant difference regarding patient age and frequency of lymphovascular invasion or myometrial invasion. As may be anticipated from the concentration of late stage cases in the BAF250a negative group, patient outcomes were worsened in that group on univariate analysis. In conclusion, we found in this pilot assessment that 22.7% of endometrial CCC displays complete loss of BAF250a expression. There was a disproportionate concentration of BAF250a negative cases in the late stage group, with the attendant possibility of an associated worsened prognosis for those CCC patients whose tumors are BAF250a negative. These preliminary findings suggest the need for larger analyses to evaluate the prognostic significance, if any, of the loss of BAF250a expression in this rare histotype of endometrial cancer.

Expression of tissue factor and heparanase in endometrial clear cell carcinoma: possible role for tissue factor in thromboembolic events.

Earlier reports have indicated that patients with endometrial clear cell carcinoma (CCC) may have an increased risk for thromboembolic events. Tissue factor is a 47-Kd transmembrane glycoprotein that plays a critical role in platelet activation, fibrinogenesis, blood clot formation, and as such, general hemostasis. The mammalian heparanase is an endo-ß-glucuronidase that can cleave heparan sulfate at specific molecular sites, resulting in structural modification of the extracellular matrix barrier, facilitating cancer cell invasion, and eventual metastasis. Recent reports indicate that heparanase may also induce tissue factor expression. The purpose of this study is to assess the clinicopathologic significance of tissue factor and heparanase expression, especially as they relate to the risk of thromboembolic events, in endometrial CCC and selected other endometrial cancers. Eighty-four endometrial carcinomas, including 17 CCC, 20 endometrial serous carcinomas, 15 grade 1 endometrial endometrioid carcinomas (EEC), 15 grade 2 EEC, 10 grade 3 EEC, and 7 mixed endometrial carcinomas with at least a 10% clear cell component (mixed CCC) were evaluated for the immunophenotypic expression of heparanase and tissue factor, and their associated frequency of thromboembolic events. Seven of the 84 patients experienced 8 thromboembolic events during the follow-up period. By multivariate analysis, the pure CCC histotype [odds ratio 5.2; 95% confidence interval (CI): 2.4523-13.6754; P=0.026] was significantly associated with an elevated risk for thromboembolic events. Tissue factor expression was present in 12 (14.28%) of the 84 endometrial carcinomas, including in 7 (41.17%) of 17 pure CCC, 2 (10%) of 20 endometrial serous carcinomas, 1 (14.3%) of 7 mixed CCC, 2 (13.3%) of 15 grade 1 EEC, and in 0% of grade 2 and 3 EEC. Tissue factor expression was significantly more likely to be seen in pure CCC than in all other cancers as a group (P=0.0018) and in all other high-grade endometrial cancers (P=0.007). By multivariate analysis, tissue factor expression was significantly associated with the risk of thromboembolic events [odds ratio 4.8 (95% CI: 1.9196-11.93), P=0.013]. Tissue factor expression was not associated with patient outcome or any other clinicopathologic parameter. Heparanase expression was present in 57 (67.8%) of the 84 endometrial carcinomas, and was significantly associated with the endometrioid histotype, but not outcome or the risk of thromboembolic events. For the overall group of all cancers, there was no significant correlation between heparanase and tissue factor expression (Spearman rank correlation, r=0.311, P=0.4). In summary, patients with endometrial CCC have an increased risk of developing thromboembolic events compared with patients with the other histotypes. This increased risk may be related, at least partially, to an increased rate of tissue factor expression in endometrial CCC.

Patterns of bone morphogenetic protein-2 expression in smooth muscle tumors of the uterine corpus and other uterine tissues.

Bone morphogenetic proteins (BMPs) are extracellular, multifunctional growth factors that constitute the largest subset of the transforming growth factor ß superfamily. BMP2 is involved in cardiovascular embryogenesis, in addition to a variety of other postnatal functions, such as neovascularization, osteoinduction, tumor signaling, and in the uterus, stromal decidualization at the implantation site. Estrogen receptor signaling is common in smooth muscle tumors of the uterus, and preclinical models suggest significant interactions between BMP2 and estrogen receptor-mediated signaling. The purpose of this study is to define the patterns of BMP2 expression, as assessed by immunohistochemistry, in smooth muscle tumors and other tissues of the uterine corpus, and to establish whether BMP2 expression has any prognostic significance in uterine leiomyosarcomas. BMP2 was positive (cytoplasmic pattern, typically focal) in 24% of leiomyosarcomas and 20.7% of leiomyomata, but was either infrequently expressed or not expressed in all other tissues evaluated, including normal myometrium and endometrium, endometrial stromal tumors, typical adenomyoma, adenomyosis, and serosal endometriosis. The endothelial cells of small, thin-walled vessels were frequently, but not invariably immunoreactive for BMP2. There was no significant difference between BMP2⁺ and BMP⁻ leiomyosarcomas regarding average tumor size, average patient age, microvessel density, and proportions with high tumor grade, advanced stage and frequency of death from disease on follow-up. Two (29%) of 7 BMP2⁺ leiomyosarcomas were estrogen receptor+, compared with 5 (50%) of 10 BMP2⁻ leiomyosarcomas, a statistically insignificant difference (P=0.62). It is concluded that BMP2 is only expressed in a minority of smooth muscle tumors of the uterine corpus, and lacks prognostic significance in leiomyosarcomas. BMP2 is rarely expressed in the other nonendothelial tissues of the human uterine corpus that were evaluated. The significance of frequent BMP2 expression in small vessels of the uterus requires further investigation.

Papillary renal cell carcinoma with diffuse clear cells and thyroid-like macrofollicular areas.

Papillary renal cell carcinoma may display some unusual morphologic variations, including diffuse oncocytic change not otherwise specified, oncocytic change associated with an inverted nuclear pattern or nonoverlapping low-grade nuclei, low-grade spindle cells, and diffuse clear cells. Tumors comprised predominantly of thyroid-like follicles and inspissated eosoinophilic, colloid-like secretions (thyroid-like follicular carcinoma of the kidney) have been recently recognized. We report herein an unusual renal carcinoma that displayed diffuse clear cells, papillary architecture, foamy histiocytes, psammomatous calcifications, and large areas (approximately 20% of tumor volume) with thyroid macrofollicular-like structures and eosinophilic, colloid-like secretions. The tumor was diffusely positive for alpha-methylacyl-CoA racemase, cytokeratin 7 and CD10, and was entirely negative for CD15, thyroglobulin, thyroid-transcription factor-1, TFE3, and renal cell carcinoma antigen. Fluorescence in situ hybridization using centromeric DNA probes for chromosomes 7, 17, 3, and 3p25 showed gains only in chromosome 7 and no other aberrations. The tumor was accordingly classified as an unusual morphologic variation of papillary renal cell carcinoma. This case affirms the potential for papillary renal cell carcinoma to display a diffuse complement of clear cells, and documents the heretofore unreported finding of large areas of thyroid macrofollicular structures and eosinophilic, colloid-like secretions in this histotype.

Pleomorphic rhabdomyosarcoma of the uterine corpus: a clinicopathologic study of 4 cases and a review of the literature.

We report the clinicopathologic features of 4 cases of pure pleomorphic rhabdomyosarcoma of the uterine corpus with an emphasis on their frequent expression of CD10 and CD56, review the relevant literature, and discuss differential diagnostic considerations. The patients ranged from 51 to 79 years (mean 68 y). All were FIGO stage IIIC to IV at initial surgical staging, and 3 were dead from the disease at an average of 8.6 months follow-up. In addition to the expected findings, other notable morphologic features included tumor giant cells (4/4), osteoclast-like giant cells (1/4), patchy myxoid stroma (4/4), and only infrequent cytoplasmic cross striations (1/4). The tumors in all 4 cases were positive for myogenin, myo-D1, smooth muscle actin, desmin, muscle-specific actin (HHF-35), and CD10; 3 (75%) of 4 cases were positive for calponin and CD56; all cases were negative for cytokeratin 7, synaptophysin, epithelial membrane antigen, placental-like alkaline phosphatase, chromogranin, and a pan-keratin. Twenty-three cases have been reported earlier in the English-language literature between 1969 and 2009. In combination with the current 4, the 27 patients had an age range of 35 to 87 years (mean 66.33 y). Only 1 patient was deemed inoperable; most had staging operations. Following their initial evaluations, 16 (59%) were found to have extrauterine extension of disease. At follow-up, 73% (19/27) were dead from the disease and 19.2% had no evidence of recurrence. Ten (53%) of the 19 deaths occurred within 6.5 months of initial evaluation. Stage at presentation did not have any significant impact on outcome: 73% of the 11 patients with uterus-confined disease at presentation were dead from the disease at follow-up, a rate of disease-associated death that was nearly identical to the 75% in the 16 patients with extrauterine disease at presentation. A wide variety of neoadjuvant and adjuvant therapies were administered, which did not appear to significantly impact outcomes. These data indicate that pleomorphic rhabdomyosarcoma of the uterine corpus is a highly aggressive, rapidly progressive tumor with a high case-fatality rate.

Pleomorphic lymphoepithelioma-like carcinoma of the urinary bladder.

Lymphoepithelioma-like carcinoma (LELC) of the urinary bladder is often mixed with conventional transitional cell carcinoma and/or other histotypes. The pathologist's determination of the morphologic purity of a given LELC at the biopsy stage is a clinically relevant endeavour, because there is some anecdotal evidence suggesting that pure or predominant LELC may be comparatively chemosensitive and have a favorable prognostic profile, which may potentially offer the possibility of effective therapy without bladder resection. The precise degree of cellular pleomorphism that is allowed in a pure LELC is unclear. We describe herein an otherwise conventional and pure LELC that showed, in a localized area that constituted approximately 25% of the overall tumor volume, a two to six fold variation in nuclear size, including multinucleated tumor cells. These pleomorphic areas were set in the same lymphoplasmacytic infiltrate as their conventional counterparts, and similarly displayed cellular syncytia. We performed a detailed immunophenotypic comparison between the conventional areas and the pleomorphic areas. No significant differences were found between the 2 areas in overall lymphoplasmacytic or histiocytic density, lymphocytic CD4/CD8 ratio, and lymphoplasmacytic kappa/lambda ratio. Similarly, both displayed similar qualitative and quantitative staining indices for p53, Ki67, cytokeratin AE1/AE3 and p16(INKa). Scattered cells were cytoplasmically beta-catenin positive exclusively in the pleomorphic areas; however these cells were not notably larger than the cells in the conventional areas. Both components were immunohistochemically negative for HMB-45, CD1a, the estrogen receptor, Epstein-Barr virus, CD117, D2-40, CD56, cytokeratin 20 and chromogranin. Clinicopathologic analysis of a series of cases is required to establish if there is any significance to nuclear pleomorphism in LELC. However, the phenotypic similarity between the 2 areas in this case, the intimate admixture of the pleomorphic cells with the lymphoplasmacytic infiltrate, and their syncytial pattern of growth, all suggest that pure LELC may display marked nuclear pleomorphism, and that this finding may not, in of itself, be a valid basis for removing a case from the "pure" group.

A comparative analysis of lymphatic vessel density in ovarian serous tumors of low malignant potential (borderline tumors) with and without lymph node involvement.

Lymph node involvement is seen in approximately one quarter of women with surgically staged ovarian serous tumors of low malignant potential (serous borderline tumors), and this finding apparently does not adversely impact their overall survival. To help illuminate some of the pathomechanisms underlying this novel phenomenon, in which a largely noninvasive epithelial neoplasm is able to exit its primary site and be transported to lymph nodes with such a substantial frequency, we investigated whether significant differences in lymphatic vessel density exist between ovarian serous borderline tumors that show lymph node involvement and those that do not. The lymphatic vessel density of 13 conventional ovarian serous borderline tumors (i.e. tumors without stromal microinvasion, micropapillary/cribriform areas, or invasive implants) with at least 1 positive lymph node (study group) was compared with the lymphatic vessel density of an age- and disease extent-matched control group of 13 similarly selected lymph node-negative ovarian serous borderline tumors. Lymphatic vessel density was determined by counting the total number of vascular spaces immunohistochemically stained by the lymphatic endothelium marker D2-40 in 5 consecutive microscopic fields (x20 objective, field area of 1 microscopic field, 0.95 mm) in the most vessel-dense areas and calculating the average value per microscopic field. The peritumoral lymphatic vessel density was significantly higher than the intratumoral lymphatic vessel density in both groups. However, no statistically significant differences were found between the study and control groups regarding intratumoral lymphatic vessel density (8.0 vs. 7.61; P=0.77), peritumoral lymphatic vessel density (20.33 vs. 21.0; P=0.79), or combined, that is, peritumoral plus intratumoral lymphatic vessel density (27.81 vs. 28.62; P=0.83). Our findings, in conjunction with others in the medical literature, do not support a role for tumor lymphatics in nodal metastasis in this neoplasm. We discuss the possibility that nodal deposits may represent metastatic disease from secondary tumor implants.

Does the radiofrequency impedance-controlled endometrial ablation have any morphologic effects on uterine leiomyomata? Report of 3 cases.

A variety of novel endometrial ablation technologies are now in routine use. A subset of uteri that had previously undergone these treatments will ultimately be evaluated by the pathologist. However, the full spectrum of histologic changes that may result from these treatments has received only sporadic attention. The NovaSure [Hologic Corporation, Marlborough, MA, USA] endometrial ablation system is one of several available second-generation technologies and its particular endometrial ablative power is based on the delivery of radiofrequency energy. The present analysis was designed to decipher any histologic changes (if any) associated with the NovaSure endometrial ablation system relative to benign smooth muscle tumors of the uterine corpus. Over a one-year period, 3 uteri that had previously undergone the NovaSure endometrial ablation and which also had leiomyomatous mass lesions were evaluated. The leiomyomatous mass lesions were extensively sampled and were evaluated for cellular shapes (epithelioid change, cellular rounding, extraordinary cytoplasmic eosinophilia, clear cell change, cytoplasmic vacuolation), nuclear changes (nucleomegaly, nucleolomegaly, multinucleation, hyperchromasia, symplastic changes), necrosis (coagulative and/or infarct), mitotic activity, apoptotic bodies or pyknotic cells, myxoid change, hyalinization. The three uteri were resected 61, 47 and 74 (mean 60.7) days post-ablation. After a detailed evaluation of multiple submucosal, intramural and subserosal leiomyomata from these 3 uteri, no noteworthy histologic changes were identified in the tumors. Since the presence or absence of tumor necrosis is one histologic criterion by which malignant potential is assigned to uterine smooth muscle neoplasms, defining any extrinsic processes that may establish, or contribute to this finding is clinically relevant. The findings reported herein suggests that if a leiomyoma that was obtained from a patient that had recently undergone the NovaSure endometrial ablation displays any degenerative changes such as necrosis, the changes are probably not attributable to the ablation.