Ovarian mixed-epithelial carcinomas with a microcystic pattern and signet-ring cells

Ovarian Signet-ring Stromal Tumor: A Morphologic, Immunohistochemical, and Molecular Study of 7 Cases With Discussion of the Differential Diagnosis

Signet-ring stromal tumor (SRST) is a rare ovarian stromal neoplasm characterized by a population of bland signet-ring cells, devoid of mucin or lipid, in a generally cellular fibromatous stroma. Previous reports have described heterogenous immunohistochemical and molecular genetic findings, including occasional nuclear β-catenin expression and/or CTNNB1 mutations. We report 10 ovarian stromal neoplasms originally diagnosed as SRST. All but 1 tumor underwent detailed immunohistochemical analysis (including β-catenin) and 5 of 10 had CTNNB1 mutation analysis performed. All tumors contained a population of morphologically bland signet-ring cells that ranged from 15% to 95% of the neoplasm, characterized by a single large empty intracytoplasmic vacuole, mostly with nuclear indentation. Six of the 10 tumors contained cellular fibroma-like areas, comprising from 10% to 85% of the neoplasm. Three of the 10 tumors were reclassified as microcystic stromal tumor with signet-ring cells on the basis of the microcyst formation and hyalinized stroma, beta-catenin and cyclin D1 nuclear expression and/or CTNNB1 mutation, CD10 staining and largely absent expression of inhibin and calretinin. In the remaining 7 tumors, the diagnosis of SRST remained, constituting the largest series of SRST reported in the literature to date. The results of our study suggest that a subset of tumors diagnosed as ovarian SRST, especially those which show β-catenin nuclear positivity and/or CTNNB1 mutation, likely represent microcystic stromal tumor with variant morphology. We also suggest that at least a subset of SRSTs without evidence of Wnt/β-catenin pathway abnormalities may be related to ovarian fibromas. We discuss the differential diagnosis of ovarian neoplasms containing signet-ring cells.

Signet-ring cells in pleural and peritoneal effusions identified on Wright stains – A diagnostic pitfall

Objectives:

Signet-ring cells (SRCs) in effusion specimens represent a diagnostic challenge. In this study, a consecutive series of pleural and peritoneal effusions with benign SRCs are examined and compared with malignant SRCs.

Material and Methods:

We reviewed consecutive Wright-stained serous effusion slides and searched for cases with SRCs. Corresponding ThinPrep slides and clinical histories were reviewed. Cytology cases with known signet-ring adenocarcinoma were retrieved and reviewed.

Results:

Four hundred Wright-stained serous effusions were reviewed. Eighteen cases were identified with SRC-like cells. Thirteen patients had liver cirrhosis, three patients had end-stage renal disease, one patient had a history of pancreatic adenocarcinoma, and one patient had endometrioid carcinoma. For the latter two patients, the primary tumor showed no histologic findings of signet-ring features. In all cases, no SRCs were found on the corresponding ThinPrep slides. Five cytology cases with malignant SRCs were reviewed. Benign SRCs have a uniformly pale and markedly distended cytoplasm, and the nuclei are thin and curved. The malignant SRCs showed larger non-curved nuclei and bubbly mucin-containing cytoplasm.

Conclusion:

Mesothelial cells and histiocytes can mimic signet-ring adenocarcinoma cells on Wright-stained slides. Correlation with ThinPrep specimens is necessary before reporting, as the SRCs typically are not present in ThinPrep preparations.

A prognostic nomogram for women with primary ovarian signet-ring cell carcinoma

Background

Primary ovarian signet-ring cell carcinoma (POSRCC) is a rare subtype of ovarian carcinoma that is characterized by abundant mucin accumulation. POSRCC is aggressive, and the prognostic factors associated with its clinical outcome remain poorly defined. This study aimed to elucidate the clinical characteristics and survival of patients with POSRCC, and to establish an effective prognostic nomogram and risk stratification model to predict the risks associated with patient outcomes.

Methods

Data of patients with POSRCC from the period 1975 to 2016 were collected from the Surveillance, Epidemiology, and End Results (SEER) database. Univariable and multivariable analyses of demographic factors, clinicopathological characteristics, and treatments were conducted to identify significant prognostic parameters. The identified independent variables were integrated to develop a nomogram and risk stratification model. The discrimination and calibration of the nomogram were assessed with the concordance index (C-index), receiver operating characteristic (ROC) curves, and calibration curves.

Results

A total of 172 patients were identified as being eligible to participate in this study. The median overall survival (OS) time was 7 months [95% confidence interval (CI), 4.6-9.4 months]. The 1-, 3-, and 5-year OS rates were 35.5%, 15.3%, and 6%, respectively. A multivariable analysis of the primary patients identified the independent predictors for survival as age at diagnosis, race, marital status, T (primary tumor size) stage, and chemotherapy, which were all incorporated into the nomogram. The C-index was 0.70 (95% CI, 0.66-0.75), which was statistically higher than that of the International Federation of Gynecology and Obstetrics (FIGO) staging system (0.58; 95% CI, 0.53-0.63). ROC curve analysis also showed that the nomogram had good discrimination, with an area under the curve (AUC) of 0.74, 0.62, and 0.71 for 1-, 3-, and 5-year survival, respectively. The calibration curves showed good agreement between the prediction by the nomogram and actual observations. A risk stratification model was further used to classify patients into a low-risk or high-risk group. The median OS time for the low- and high-risk groups was 13.0 months (95% CI, 9.33-16.67) and 2.0 months (95% CI, 1.12-2.89), respectively. Surgery did not significantly prolong survival in either group [low-risk group: hazard ratio (HR), 0.69; 95% CI, 0.45-1.07; P=0.09; high-risk group: HR, 0.55; 95% CI, 0.46-0.67; P=0.18].

Conclusions

The proposed nomogram and risk stratification model showed accurate prognostic prediction for POSRCC. These methods could improve individualized evaluations of survival and therapeutic decisions for patients with POSRCC.

Ovarian Mixed Malignant Brenner-Mucinous Tumor with Signet Ring Cells

Mucinous carcinomas with signet ring cells in the ovary, particularly those composed predominantly of signet ring cells, are extremely rare, and in vast majority of cases, they represent metastasis from another site such as the stomach, appendix, pancreaticobiliary tract, bladder, and breast (Hristov et al., 2007, Kiyokawa et al., 2006, Vang et al., 2006, Young, 2006). Malignant Brenner tumor is also rare comprising less than 0.5% of ovarian carcinoma. Although mixed Brenner-Mucinous tumors are relatively common, the combination of a primary ovarian signet ring carcinoma with a malignant Brenner tumor is unique and to the best of our knowledge not previously reported in the literature.

Ovarian tumors: a survey of selected advances of note during the life of this journal

The author reviews highlights of advances in knowledge concerning ovarian tumor pathology since the time of an essay in the first issue of this Journal written by Dr Robert E. Scully, who, both before and for several decades after the Journal was instituted, made many original contributions to the field and was the major architect of the 1973 World Health Organization classification of ovarian tumors which was much more clear and logical than prior ones. The current review considers the neoplasms in essentially the same order as was done in the first issue of this journal and presents a personal look at the highlights of new information concerning various well-known categories, surface epithelial, germ cell, sex cord-stromal, metastatic neoplasms and briefly, benign so-called tumor-like lesions. Some of the most notable developments are as follows: (1) an orderly approach to the classification of implants of serous borderline tumors into noninvasive and invasive categories; (2) recognition of distinctive micropapillary patterns seen in some borderline tumors and low-grade carcinomas; (3) a remarkable propensity for some endometrioid carcinomas to mimic sex cord- stromal tumors; (4) appreciation of the differences between primary mucinous tumors of intestinal and müllerian types; (5) the importance of distinguishing within primary mucinous carcinomas between expansile and destructive stromal invasion; (6) emphasis on the diagnosis of immature teratoma being based on the presence of primitive-embryonic-appearing tissues; (7) appreciation of variant morphology of cases of struma ovarii which may lead to significant diagnostic problems; (8) subdivision of granulosa cell tumors into adult and juvenile types because of the differing features of the two groups including in the second category the propensity for more malignant neoplasms to be mimicked; (9) recognition of a distinctive form of Sertoli-Leydig cell tumor, the retiform variant, with a propensity to occur in the young; (10) appreciation of a unique highly malignant neoplasm that typically afflicts the young and may be associated with hypercalcemia, so-called small cell carcinoma of hypercalcemic type; (11) greater awareness than was hitherto the case of the propensity for metastatic intestinal adenocarcinoma to mimic primary endometrioid carcinoma and similarly for metastatic mucinous carcinomas to simulate primary mucinous cystic tumors; (12) recognition of the distinctive features of low-grade appendiceal mucinous neoplasms that spread to the ovary and are typically associated with pseudomyxoma peritonei; and (13) appreciation that the histologic spectrum seen in cases of Krukenberg tumor is broader than often previously thought.

Low-Stage High-Grade Serous Ovarian Carcinomas: Support for an Extraovarian Origin

Many adnexal high-grade serous carcinomas (HGSCs) may derive from microscopic precursors in the fallopian tube. By studying a series of low-stage ovarian carcinomas, we anticipated that HGSCs would be distributed in a pattern suggesting secondary involvement, helping to indirectly validate the fallopian tube origin theory, and that most ovarian carcinomas other than serous carcinomas would demonstrate features consistent with derivation from precursors located in or transplanted to the ovary. Seventy-six patients with low-stage (FIGO I/II) sporadic ovarian carcinoma who underwent primary surgical management at Memorial Sloan Kettering Cancer Center from 1980 to 2000 were included in the study. Histologic type was assigned using Gilks' criteria. Similar to the approach taken when distinguishing primary and metastatic mucinous or endometrioid carcinoma involving ovary, cases interpreted as showing a "primary" pattern of ovarian involvement had ≥3 of the following features: unilateral tumor, size >12 cm, no surface involvement, no multinodularity, and no destructive stromal invasion. All other cases were considered to show a "metastatic" pattern of ovarian involvement. Cases were evaluated for p53 and WT-1 expression, using standard techniques on a tissue microarray. TP53 gene sequencing was also performed. Cases comprised HGSC (n=22), endometrioid carcinoma (n=30), clear cell carcinoma (n=13), and mucinous carcinoma (n=11). HGSCs displayed substantially more "metastatic features" than the non-HGSC group and a mean overall size that was smaller (8.85 vs. 14.1 cm). Statistically significant differences were found for bilaterality (63% vs. 7.3%), P=0.0001; multinodularity (55% vs. 7.3%), P=0.0001; tumor size, P=0.003; and surface involvement (50% vs. 13%), P=0.002. Five of 22 (23%) of HGSCs showed a "primary pattern" of ovarian involvement. There were no significant differences between these cases and "metastatic pattern" HGSCs when comparing morphology, immunophenotype, TP53 mutational status, and clinical outcomes. Most low-stage HGSCs demonstrate patterns of ovarian involvement that suggest metastasis from another source, such as the fallopian tube. Both metastatic pattern HGSCs and unilateral, low-stage HGSCs can behave aggressively.

Pregnancy complicated by a Krukenberg tumor with an undetermined origin and its management

Krukenberg tumor in pregnancy is very rare and management of this condition is a dilemma for physicians. Moreover, the existence of a primary Krukenberg tumor is still in debate. Herein, we present a 29-year-old woman at 29 weeks of pregnancy, admitted with premature labor and revealed to have a signet ring cell ovarian tumor with an undetermined primary origin. A primary Krukenberg tumor or a Krukenberg tumor with an undetermined origin has not been previously reported in a pregnant patient. By virtue of the controversy, we are not eager to use the term 'primary Krukenberg tumor' for this case, although the possibility of the existence of this kind of tumor cannot be totally ignored.

Architectural patterns of ovarian/pelvic high-grade serous carcinoma

We describe the architectural patterns of advanced ovarian/pelvic high-grade serous carcinomas that have been treated with upfront surgery, followed by adjuvant chemotherapy or neoadjuvant chemotherapy, followed by interval debulking to explore the association with the chemotherapeutic response. For 70 cases of advanced (i.e. stage III/IV) high-grade serous carcinomas (33 platinum resistant/intermediate, 37 platinum sensitive; 24 neoadjuvantly treated, 44 primary surgery), all tumor-containing histologic slides were reviewed by 1 of 3 pathologists. Histologic type was confirmed and the following features were assessed: major architectural pattern and the presence of any of 8 predefined minor architectural patterns (papillary, transitional cell carcinoma-like, micropapillary, microcystic, nested papillary, slit-like, glandular, solid). A semiquantitative assessment of psammoma bodies, histiocytic response, necrosis, nuclear atypia, and single-cell invasion was performed. Mitotic count was performed in 10 HPF and 1 HPF was counted for intraepithelial lymphocytes. The morphologic features were tested for an association with previous neoadjuvant chemotherapy and response to chemotherapy (resistant/intermediate versus chemotherapy-sensitive cases stratified by neoadjuvant chemotherapy), which was carried out using χ tests for categorical variables and analysis of variance for continuous data. Combinations of features were analyzed using unsupervised clustering (Wald). Although 8 of 18 features were significantly different when samples from neoadjuvantly treated patients were compared with those not previously treated, no individual histomorphologic feature or a combination of features was associated with response to chemotherapy. Further subtyping of high-grade serous carcinomas will likely need ancillary molecular markers that may have a greater potential to identify cases that will not respond to platinum-based chemotherapy.

Human ovarian cancer stem/progenitor cells are stimulated by doxorubicin but inhibited by Mullerian inhibiting substance

Women with late-stage ovarian cancer usually develop chemotherapeutic-resistant recurrence. It has been theorized that a rare cancer stem cell, which is responsible for the growth and maintenance of the tumor, is also resistant to conventional chemotherapeutics. We have isolated from multiple ovarian cancer cell lines an ovarian cancer stem cell-enriched population marked by CD44, CD24, and Epcam (3+) and by negative selection for Ecadherin (Ecad-) that comprises less than 1% of cancer cells and has increased colony formation and shorter tumor-free intervals in vivo after limiting dilution. Surprisingly, these cells are not only resistant to chemotherapeutics such as doxorubicin, but also are stimulated by it, as evidenced by the significantly increased number of colonies in treated 3+Ecad- cells. Similarly, proliferation of the 3+Ecad- cells in monolayer increased with treatment, by either doxorubicin or cisplatin, compared with the unseparated or cancer stem cell-depleted 3-Ecad+ cells. However, these cells are sensitive to Mullerian inhibiting substance (MIS), which decreased colony formation. MIS inhibits ovarian cancer cells by inducing G1 arrest of the 3+Ecad- subpopulation through the induction of cyclin-dependent kinase inhibitors. 3+Ecad- cells selectively expressed LIN28, which colocalized by immunofluorescence with the 3+ cancer stem cell markers in the human ovarian carcinoma cell line, OVCAR-5, and is also highly expressed in transgenic murine models of ovarian cancer and in other human ovarian cancer cell lines. These results suggest that chemotherapeutics may be stimulative to cancer stem cells and that selective inhibition of these cells by treating with MIS or targeting LIN28 should be considered in the development of therapeutics.

WT1 expression in the female genital tract

The Wilms tumor gene 1 (WT1) has been reported in normal tissues and many neoplasms of the female genital tract. This review discusses WT1 expression in the female genital tract and its potential utility in the differential diagnosis of neoplasms that occur at this location. WT1 is of value in the differential diagnosis of synchronous serous carcinomas arising in the ovary/fallopian tube/peritoneum and endometrium, as strong WT1 positivity in both tumors points toward an extrauterine origin. In addition, WT1 can be used to distinguish sex cord stromal tumors (WT1 positive) from endometrioid carcinomas (OECs). WT1 expression is not helpful in the differential diagnosis of ovarian serous carcinomas (OSCs) and transitional carcinomas, as both are typically positive and has limited value in the distinction of serous tumors arising in the ovary/fallopian tube/peritoneum from mesotheliomas. WT1 is also not helpful to differentiate small cell carcinoma of hypercalcemic type from juvenile granulosa cell tumor, a common diagnostic problem. Intra-abdominal desmoplastic round cell tumor reacts to WT1 (C-terminal) in contrast to all other tumors discussed which helps to separate this rare tumor from most other small round cell tumors that may involve, primarily or secondarily, the ovary with the exception of small cell carcinoma of hypercalcemic type that typically reacts with the N-terminal of WT1.

Nonserous Ovarian Epithelial Tumors

This review covers the group of relatively uncommon nonserous ovarian epithelial tumors. The authors focus on the group's distinctiveness from the much more common serous tumors and show the similarities across entities. Diagnostic criteria that separate the different entities are currently being debated. Particular problems include the reproducible diagnosis of high-grade endometrioid, transitional cell, mixed epithelial and undifferentiated carcinomas. Furthermore, despite recognition that most malignant mucinous tumors involving ovary represent metastases from extraovarian primary sites, many misdiagnoses still occur. The authors discuss their rationale behind their opinions about these problematic topics.

Endometrial adenocarcinoma with signet ring cells: report of two cases of an extremely rare phenomenon

The presence of signet ring cells in a carcinoma within the uterine corpus strongly raises the possibility of a metastasis from a primary tumor in the breast, gastrointestinal tract, or elsewhere. Signet ring cells are extremely rare in primary endometrial adenocarcinomas with only a single prior case report. We report 2 cases of primary endometrial adenocarcinoma, one of mucinous and the other of endometrioid type, with a significant component of signet ring cells. One of the neoplasms arose within adenomyosis. In reporting these cases, we illustrate that the presence of signet ring cells does not preclude a primary endometrial adenocarcinoma.We discuss signet ring cells in the endometrium.

Primary signet ring cell mucinous ovarian carcinoma: a case report and literature review

A 24-year-old female patient presented with an extremely rare primary signet cell carcinoma of the right ovary 1 year after surgery for a mucinous borderline tumour of the left ovary. Relaparotomy was carried out with right adnexectomy, appendectomy and partial omentectomy. Surgery was followed by 6 courses of paclitaxel/carboplatinum chemotherapy. After an initial response, the patient again developed increasing ascites. The patient was transferred to our hospital and a re-relaparotomy was carried out, completing the operation. After 3 courses of pegylated doxorubicin/trabectedin, the clinical course showed a positive response and a decline of the tumour marker CEA in peripheral blood. After 5 months, ascites developed in the retroperitoneum so that the chemotherapy had to be changed. In spite of a positive response with the new chemotherapy, the patient died of a very rare pulmonary complication after 1 month within 2 days.

Vacuolated cell pattern of pancreatobiliary adenocarcinoma: a clinicopathological analysis of 24 cases of a poorly recognized distinctive morphologic variant important in the differential diagnosis

Pancreatic ductal adenocarcinoma (PDCA) is characterized by well-defined tubular units in the vast majority of the cases; however, variations in this theme do occur. It is important to recognize the morphologic spectrum of PDCA to avoid misdiagnosis especially in small specimens and also in metastatic foci. Here, we document a morphologic variant of PDCA that is characterized by a distinctive pattern of infiltrating cribriform nests in a distinctive "microcystic" or "secretory" pattern. Twenty-four cases of PDCA have been identified in a review of 505 cases diagnosed with PDCA. Histologically, this pattern was characterized by infiltrating nests of tumor cells with large vacuoles and "signet-ring" like appearance imparting a cribriform growth pattern. The vacuoles were one to five cells in size, often merging to form multilocular spaces separated by a thin rim of cell membrane. Many of these spaces contained CA19.9 positive granular secretory material. The nuclei were often pushed to the periphery and compressed in a pattern resembling adipocytes, although the nuclei were often densely hyperchromatic and displayed significant atypia. Especially in biopsies from the peripancreatic fat and peritoneum, these neoplastic cells had been misdiagnosed as degenerating adipocytes, and in the lymph nodes, they had been misinterpreted as lipogranulomas. Clinical findings of the patients were similar to that of conventional PDCA, except higher incidence of history of smoking (83% vs. 60%; p=0.034). In conclusion, vacuolated cell adenocarcinoma is a distinct morphologic variant of PDCA, and the presence of this peculiar pattern in a metastatic site, although not specific, should raise the suspicion of a PDCA.

Ovarian low-grade and high-grade serous carcinoma: pathogenesis, clinicopathologic and molecular biologic features, and diagnostic problems

Ovarian serous carcinomas have been graded using various systems. Recently, a 2-tier system in which tumors are subdivided into low grade and high grade has been proposed. This approach is simplistic, reproducible, and based on biologic evidence indicating that both tumors develop via different pathways. Low-grade serous carcinomas exhibit low-grade nuclei with infrequent mitotic figures. They evolve from adenofibromas or borderline tumors, have frequent mutations of the KRAS, BRAF, or ERBB2 genes, and lack TP53 mutations (Type I pathway). The progression to invasive carcinoma is a slow step-wise process. Low-grade tumors are indolent and have better outcome than high-grade tumors. In contrast, high-grade serous carcinomas have high-grade nuclei and numerous mitotic figures. Identification of a precursor lesion in the ovary has been elusive and therefore the origin of ovarian carcinoma has been described as de novo. More recently, studies have suggested that a proportion seem to originate from intraepithelial carcinoma in the fallopian tube. The development of these tumors is rapid (Type II pathway). Most are characterized by TP53 mutations and lack mutations of KRAS, BRAF, or ERBB2. Although both types of serous carcinomas evolve along different pathways, rare high-grade serous carcinomas seem to arise through the Type I pathway. Immunohistochemical stains for p53, p16, and Ki-67 for distinction of low-grade from high-grade tumors are of limited value but can be helpful in selected instances. This review provides an update on the pathogenesis and clinicopathologic features of these 2 types of serous carcinomas and addresses some of the diagnostic problems that are encountered in routine practice.

Carcinoma of extrahepatic bile ducts and gallbladder metastatic to the ovary: a report of 16 cases

Information on ovarian metastasis of carcinoma of the extrahepatic bile ducts and gallbladder is limited. Sixteen examples are reported; 3 primary tumors were hilar cholangiocarcinomas, 5 common bile duct carcinomas, and 8 gallbladder carcinomas. The patients ranged from 21 to 87 years (mean, 59 years); 7 presented to gynecologists with nonspecific pelvic symptoms similar to primary ovarian neoplasms. The primary tumor was identified before the detection of the ovarian lesions in 5 cases, was simultaneously detected with the ovarian metastases in 9, and was diagnosed postoperatively in 2. All but one case had bilateral ovarian involvement. The thirty-one ovarian lesions included twenty-nine grossly abnormal ovaries that were enlarged (range, 3.0-16.5 cm, mean, 9.4 cm) and 2 ovaries with only microscopic involvement. The sectioned surface was solid in 9, solid-cystic in 15, and multicystic in 5. Microscopically, ovarian surface implants were seen in 66%, multinodular growth in 58%, and infiltrative stromal invasion in 81%. Mucinous epithelial differentiation was seen in 81%, sometimes with foci of benign-like or borderline-like epithelium simulating primary ovarian mucinous neoplasia. Cystadenoma and cystadenofibroma of nonmucinous type was even mimicked strikingly in some cases because of flattening of epithelium lining glands and cysts. Signet ring cells were present in sufficient quantity for a diagnosis of Krukenberg tumor in four tumors. Colloid-type carcinoma was observed at least focally in 3 tumors. Nonmucinous carcinomatous components included adenocarcinoma with high-grade endometrioid-like morphology in 2 cases, papillary adenocarcinoma simulating mixed müllerian epithelial adenocarcinoma in 1, and undifferentiated carcinoma in 2. Immunohistochemical studies in 8 cases showed a positive reaction for cytokeratin 7 in all and for cytokeratin 20 in 4 cases. The high rate of bilaterality, surface involvement, multinodular growth, and heterogeneity of patterns were the most helpful features for indicating a metastatic nature, with signet ring cells also being helpful in the minority of cases in which they were present. Although the diagnosis of a metastatic tumor to the ovary is possible in most of the cases based on standard diagnostic criteria, problems in the differential diagnosis may be posed by morphologic patterns that overlap strikingly with primary ovarian neoplasms, benign, borderline, and malignant, as discussed herein.

Primary Ovarian Adenofibromatous Neoplasms With Mucin-Containing Signet-ring Cells

The presence of mucin-containing signet-ring cells in an ovarian neoplasm is considered strong evidence for a metastatic rather than primary tumor. The clinicopathologic features of 2 ovarian adenofibromatous neoplasms with mucin-containing signet-ring cells (AFN-SRs), proven by the long-term follow-up of 10 and 15 years to be primary tumors, are presented as exceptions to this general guideline. Both of these tumors were initially strongly favored to be metastatic adenocarcinoma by expert consultants in gynecologic pathology, which underscores the diagnostic difficulty that these rare and unusual neoplasms can pose. Although long-term follow-up of AFN-SRs is still necessary to exclude the possibility of metastases, the following constellation of features can correctly suggest a primary neoplasm rather than a Krukenberg-like metastatic process at the time of presentation: (i) the appearance of fibromatous stroma as an integral part, as opposed to reactive part, of the neoplasm, (ii) a semiorganized rather than completely haphazard pattern to the placement of the epithelial elements, with a circumscribed noninfiltrative interface with ovarian parenchyma, (iii) the absence of angiolymphatic invasion, (iv) tumor unilaterality, and (v) the lack of a known primary source. The virtual absence of literature on these low-grade malignancies, coupled with the occurrence of 2 such tumors within a 7-year period at a single community hospital, suggests that many AFN-SRs continue to be misdiagnosed as metastatic adenocarcinoma.

Oxyphilic Adenomatoid Tumor of the Ovary

We describe an unusual example of ovarian adenomatoid tumor that was an incidental finding in the ovary of a 52-year-old woman and was characterized by cells with abundant eosinophilic cytoplasm, an occasional feature of the adenomatoid tumor but one that, in an ovarian example, may cause added diagnostic confusion to that already engendered by the rarity of this neoplasm in the ovary. The typical numerous small vacuoles of the neoplasm sometimes had the appearance of signet ring cells. These 2 features (oxyphil and signet ring cells) caused a broad differential. Tumor cells were positive with broad-spectrum cytokeratins as well as mesothelial markers CK5/6, WT1, and calretinin. In reporting this case, we focus on the differential diagnosis of ovarian neoplasms and tumorlike conditions with vacuoles and related spaces, a topic that embraces many diverse entities.

From krukenberg to today: the ever present problems posed by metastatic tumors in the ovary: part I. Historical perspective, general principles, mucinous tumors including the krukenberg tumor

This review considers historical aspects of metastatic tumors to the ovary, general principles that aid in their evaluation, and metastatic mucinous tumors, including the Krukenberg tumor. The historical timeline on the Krukenberg tumor dates back to the legendary Sir James Paget and the story is followed through the well-known, albeit flawed, contribution of Friedrich Krukenberg and others who have contributed important papers over the years, including the overlooked contribution of the French investigator Gauthier-Villars. Knowledge of metastatic colorectal carcinoma is traced back to the famed British surgeon Sir John Bland-Sutton and followed through to more recent contributions, including the important one of Lash and Hart. Contributions on mucinous tumors conclude the historical perspective, note being made of the recent evidence suggesting that the long held contention of Dr Robert E. Scully that ovarian mucinous tumors in patients with pseudomyxoma peritonei usually originate from the appendix is correct. The section on general principles highlights the many clinical, gross, microscopic, and special techniques such as immunohistochemistry that may aid in determining that an ovarian tumor is metastatic with emphasis on the first 3 mentioned aspects. Problematic features such as a tendency for metastatic tumors to be cystic, even when the primary tumors are not, and for many metastatic tumors to mature in the ovary (so-called maturation phenomenon), are emphasized. Of the many helpful findings that resolve the problem, the characteristic features of surface implants are highlighted. The contribution on the Krukenberg tumor reviews the varied microscopy of this tumor pointing out that the well-known pattern of signet-ring cells in a cellular stroma, albeit characteristic, is often not striking and frequently overshadowed by other microscopic features. The latter include, in many cases, a rather unique microcystic pattern. The final portion of the essay reviews mucinous tumors of non-Krukenberg type, beginning with those that originate from the appendix. The appendiceal neoplasms have distinctive features in most cases being particularly well differentiated, and this is also seen in their ovarian metastases. Other mucinous tumors that commonly simulate closely metastatic neoplasms, include those from the pancreas in particular, but also diverse other sites, are then reviewed.

Primary extracranial meningioma of the pelvis: a light microscopic, immunohistochemical, and ultrastructural study

BACKGROUND

Extracranial meningiomas are rare tumors which have been described in head and neck. The occurrence in mediastinum and retroperitoneum is even rarer. This presented case records a unique location, a meningioma arising in pelvis.

CASE

A 52-year-old woman presented with an ovarian mass. The histology of the resected tumor revealed sheets of bland epithelioid cells arranged in prominent whorls with psammoma bodies typical of meningothelial meningioma. Immunohistochemical analysis demonstrated diffuse strong positivity for vimentin and epithelial membrane antigen (EMA). There was moderate reactivity for cytokeratin, estrogen (ER) and progesterone (PR) receptors. By electron microscopy, the tumor cells expressed desmosomes and abundant intermediate filaments.

CONCLUSION

According to our review of literature, this is the first reported case of a primary pelvic meningioma. Its benign appearance and 4-year disease-free survival without clinical or radiological evidence of intracranial disease favors the pelvis as the primary site.

Transitional Cell Carcinoma of the Ovary

Transitional cell carcinoma (TCC) of the ovary is a recently recognized subtype of ovarian surface epithelial-stromal cancer, and studies of its morphology are few. As a result, the criteria for its diagnosis and spectrum of its morphology are not clearly established. One hundred consecutive consultation cases of ovarian carcinoma with a pure or partial transitional cell pattern (excluding malignant Brenner tumor) diagnosed between 1989 and 2001 were evaluated for the frequency of various pathologic features and the relation of TCC to other surface epithelial-stromal carcinomas. The women were 33 to 94 years of age (mean, 56 years). A total of 47 tumors were stage I, 21 stage II, 31 stage III, and 1 stage IV; 13% of the stage I tumors and 41% of tumors of all stages were bilateral. The tumors ranged from 3.0 to 30 cm in greatest dimension (mean, 10 cm); 60% of them were solid and cystic, 24% solid, and 16% cystic. TCC was the exclusive or predominant component in 93% of the tumors and showed undulating (93%), diffuse (57%), insular (55%), and trabecular (43%) patterns. In four tumors with an insular growth, the pattern focally mimicked a Brenner tumor. Necrosis was present in 57% of the cases. Features that were seen in the tumors that in aggregate produced a relatively consistent appearance were "punched out" microspaces (87%), often the size of Call-Exner bodies, large cystic spaces (73%), and large blunt papillae (63%). Features that were sometimes seen, usually as a focal finding, included slit-like fenestrations (49%), bizarre giant cells (35%), small filiform papillae (18%), gland-like tubules (17%), squamous differentiation (13%), and psammoma bodies (4%). In 23 cases, TCC was a component of a mixed epithelial carcinoma, the additional components being serous adenocarcinoma in 16, endometrioid in 5, mucinous in 1, and clear cell carcinoma in 1. The tumor cells of the TCC component often were relatively monomorphic; 6% of the tumors were grade 1, 43% grade 2, and 51% grade 3. The nuclei were oblong or round and often had large single nucleoli (69%) or longitudinal grooves (48%). The cytoplasm was typically pale and granular but was rarely strikingly clear or oxyphilic. TCC of the ovary usually occurs in pure form but is also common as a component of a surface epithelial carcinoma of mixed cell type. In either situation, TCC has a constellation of architectural and cytologic features that readily distinguish it in most cases from other types of ovarian cancer. Recognition of these features will lead to a more consistent diagnosis of this tumor and aid in determining whether it has distinctive clinical features, particularly with regard to its behavior.

Primary and metastatic mucinous adenocarcinomas in the ovaries: incidence in routine practice with a new approach to improve intraoperative diagnosis

Mucinous carcinomas are reported to comprise 6-25% of ovarian carcinomas (mean 12%), but recent refinements in the interpretation of histologic features of noninvasive and metastatic mucinous carcinomas suggest that this may be an overestimate. Mucinous carcinomas in the ovaries are commonly metastatic, but the proportion of primary versus metastatic mucinous carcinomas in unselected patients is unknown. To evaluate the histologic-type distribution of ovarian surface epithelial carcinomas, a consecutive series of 124 ovarian carcinomas was reviewed using uniform current criteria. Microinvasive and intraepithelial carcinomas and carcinomas arising in germ cell and stromal tumors were excluded. To evaluate the proportions of primary and metastatic tumors among the mucinous carcinomas, 52 consecutive mucinous carcinomas from nonreferral patients were reviewed. Three of 124 primary ovarian carcinomas were pure mucinous carcinomas (2.4%). Among 52 cases of mucinous carcinomas in the ovaries, 40 (77%) were metastatic and 12 (23%) were primary. Among the 12 primary mucinous tumors, three were atypical proliferative mucinous tumors with microinvasion and nine were invasive mucinous carcinomas. Among the 40 metastatic mucinous tumors, 18 (45%) were from the gastrointestinal tract, 8 (20%) were pancreatic, 7 (18%) were gynecologic malignancies (5 cervical, 2 endometrial), 3 (8%) were from the breast, and 4 (10%) were of unknown primary site. A simple rule that classifies all bilateral mucinous carcinomas as metastatic, unilateral mucinous carcinomas <10 cm as metastatic, and unilateral mucinous carcinomas >or=10 cm as primary correctly classified 90% of the neoplasms. This algorithm for distinguishing primary and metastatic mucinous carcinomas in the ovary can be used at the time of intraoperative consultation to guide surgical management. After careful exclusion of noninvasive, microinvasive, and metastatic tumors, pure mucinous adenocarcinoma primary in the ovary appears to be substantially less common than previously reported.

Brenner tumor of the ovary with striking microcystic change

An ovarian Brenner tumor from a 39-year-old woman exhibited striking microcystic change that was so extensive it largely obscured the nature of the tumor, causing initial diagnostic difficulty. The patient presented with symptoms related to a pelvic mass and had a unilateral, 24 cm in maximal dimension, stage I tumor that was solid and cystic. Microscopic examination revealed extensive microcystic change within the epithelial nests in large areas of the tumor such that transitional-type epithelium was only recognized very focally. The tumor had minor areas (<5%) that showed marked cytological atypia and mitotic activity, interpreted as microscopic foci of intraepithelial carcinoma, but was predominantly benign. The presence of characteristic fibromatous stroma and mucinous metaplasia within the epithelial nests provided important clues to the correct diagnosis.