Search

Objectives: We recently observed expression of the "lung" marker napsin A in ovarian clear cell carcinomas and therefore sought to determine the extent of napsin A expression in a subset of ovarian neoplasms., Methods: We identified an archival series of ovarian clear cell carcinomas (n = 36), serous borderline tumors (n = 21), high-grade serous carcinomas (n = 37), and endometrioid adenocarcinomas (n = 29). Using standard immunohistochemical techniques on whole sections of formalin-fixed, paraffin-embedded specimens, we employed a panel of antibodies: napsin A (IP64), estrogen receptor (SP1), WT-1 (6F-H2), PAX-8 (BC12), and TTF-1 (SPT24)., Results: Thirty-six of 36 clear cell carcinomas showed napsin A expression, typically in a uniform pattern. None of the serous borderline tumors or high-grade serous carcinomas manifested napsin A expression. Napsin A was expressed in three (10%) of 29 endometrioid adenocarcinomas, generally in a focal pattern., Conclusions: Our study showed that napsin A is an extremely sensitive (100%) marker of ovarian clear cell carcinomas and exhibits very high specificity (100%) in distinguishing clear cell carcinomas from high-grade serous carcinomas and serous borderline tumors and 90% specificity in discriminating clear cell carcinomas from endometrioid carcinomas., (Copyright© by the American Society for Clinical Pathology.)

Squamous differentiation (SD) and morular metaplasia (MM) are frequently present in uterine endometrioid adenocarcinoma (EAC) and can mimic areas of solid tumor. We used immunohistochemical stains to further characterize these lesions, and to determine which markers would help to distinguish these metaplasias from areas of solid growth in EAC. The pathology database was searched for diagnoses of EAC from 1997 to 2007, the hematoxylin and eosin-stained slides were reviewed, and 143 cases with SD, MM, or both (SD+MM) were identified. A panel of immunohistochemical stains was performed. In particular, we were interested in PAX2 and PAX8, recently studied markers of Müllerian tissue as potential markers for differentiation of metaplasias and tumor. In addition, estrogen receptor and progesterone receptor, and Her-2/neu, were examined to determine whether there was a differential expression between the metaplasias and solid tumor that may be diagnostically useful. In addition, to further characterize MM and SD, bcl-2 as a marker of cell regulation and inhibition of apoptosis, p16 as a surrogate marker for human papillomavirus, and p63 as a marker of mature SD were studied. Adjacent normal endometrium (NEM), when present, and 20 EAC cases (FIGO Grades 1-3) without SD or MM served as controls. PAX2 was positive in NEM (58/61, 95%) and was lost in SD (15/136, 11%), MM (1/25, 4%), and EAC (57/163, 35%), whereas PAX8 was positive in all NEM (61/61, 100%) and in the majority of SD (125/136, 92%), MM (19/25, 73%), and EAC (162/163, 99%). The estrogen receptor and the progesterone receptor were expressed by the majority of EAC (148/163, 91% and 144/163, 88%, respectively), whereas both were markedly diminished in SD (56/136, 41% and 58/136, 43%) and MM (4/25, 16% and 2/25, 8%). Approximately half of the MM was positive for bcl-2 (12/25, 48%), making it an unreliable marker. Her-2/neu was negative in all cases (0%). p16 was patchy in SD (111/136, 82%), MM (22/25, 88%), and EAC (154/163, 94%), whereas p63 was predominantly positive only in SD (96/136, 71%). Estrogen receptor and progesterone receptor, PAX2, and PAX8 were helpful in differentiating MM from SD, EAC, or NEM (P<0.05). In addition, p63 distinguished between SD and MM, supporting the theory that morules do not show characteristic mature SD.

The biologic role that estrogen receptor (ER) and progesterone receptor (PR) play in ovarian sex cord-stromal tumors is poorly understood. Furthermore, immunohistochemical data on these hormone receptors in this group of neoplasms are limited and conflicting, with many reports suggesting that expression of ERalpha and/or PR is either infrequent or present at low levels in granulosa and Sertoli cell tumors. Immunohistochemical staining for ERalpha and PR was performed in 69 ovarian sex cord-stromal tumors: 41 adult granulosa cell tumors and 28 Sertoli-Leydig cell tumors. Extent of expression was scored based on the percentage of positive cells: 0, 5% or less; 1+, 6% to 25%; 2+, 26% to 50%; 3+, 51% to 75%; and 4+, 76% to 100%. Estrogen receptor alpha and PR were frequently expressed in adult granulosa cell tumors (66% and 98%, respectively) and Sertoli-Leydig cell tumors (79% and 86%, respectively). Diffuse (3+ or 4+) expression of PR was more common in adult granulosa cell tumors (68% vs. 36%; P = 0.013), whereas diffuse (3+ or 4+) expression of ERalpha was more frequent in Sertoli-Leydig cell tumors (50% vs. 20%; P = 0.010). In cases positive for both markers, adult granulosa cell tumors exhibited a focal (1+ or 2+) ERalpha/diffuse (3+ or 4+) PR coordinate profile more commonly than Sertoli-Leydig cell tumors (52% vs. 18%; P = 0.02), whereas Sertoli-Leydig cell tumors displayed a diffuse (3+ or 4+) ERalpha/focal (1+ or 2+) PR profile more frequently than adult granulosa cell tumors (36% vs. 0%; P = 0.0007). We conclude that expression of hormone receptors (based only on frequency of immunostaining) does not allow for distinction from other tumors in the differential diagnosis that are known to be frequently positive for ERalpha and PR such as endometrioid neoplasms. Most adult granulosa cell tumors and Sertoli-Leydig cell tumors share overlapping patterns of expression of ERalpha and PR with each other, but a subset of cases in each tumor category exhibits unique ERalpha/PR immunoprofiles (eg, focal ERalpha/diffuse PR in adult granulosa cell tumors and diffuse ERalpha/focal PR in Sertoli-Leydig cell tumors). These patterns of expression of ERalpha and PR may aid our understanding of the biologic differences between granulosa and Sertoli cell tumors.

Most primary ovarian mucinous tumors are of surface epithelial-stromal origin and exhibit diffuse expression of cytokeratin 7 (CK7) combined with variable expression of cytokeratin 20 (CK20); this immunoprofile distinguishes them from most lower gastrointestinal tract tumors secondarily involving the ovaries. The uncommon ovarian mucinous tumors of germ cell (teratomatous) origin have not been extensively evaluated to determine the utility of these markers and other markers of intestinal differentiation for distinguishing these tumors from metastatic gastrointestinal tract mucinous tumors. Immunohistochemical expression of CK7, CK20, CDX2, and villin was assessed in 44 ovarian mucinous tumors associated with a mature cystic teratoma. All cases lacked evidence of a nonovarian primary mucinous tumor. All mucinous tumors were unilateral; 6 cases had bilateral teratomas. All tumors displayed gastrointestinal-type mucinous differentiation, with epithelium that was commonly goblet cell-rich or hypermucinous; 21 were associated with pseudomyxoma ovarii and 3 of these had pseudomyxoma peritonei. Tumor architecture ranged from purely cystadenomatous (n=24), to proliferative (n=13), to carcinomatous (n=6); some tumors had admixtures of these patterns. One tumor had a goblet cell carcinoidlike pattern with pseudomyxoma ovarii. Three carcinomas had a signet ring cell component. Cystadenomatous tumors without pseudomyxoma ovarii (n=15) exhibited all possible CK7/CK20 coordinate expression profiles with nearly equal frequency. All proliferative tumors without pseudomyxoma ovarii (n=8) expressed CK7, most often in combination with CK20 expression. All cystadenomatous and proliferative tumors with pseudomyxoma ovarii (n=9 and n=5) were CK7-/CK20+. All carcinomatous tumors had pseudomyxoma ovarii; 3 were CK7-/CK20+, 2 were CK7+/CK20+, and 1 was CK7+/CK20-. The presence of pseudomyxoma ovarii was significantly associated with a CK7-/CK20+ profile (86% with pseudomyxoma ovarii vs. 13% without, P<0.0001), CDX2 positivity (79% vs. 0%, P<0.0001), and villin positivity (57% vs. 5%, P=0.0009). A subset of mucinous tumors associated with mature cystic teratomas exhibiting morphologic and immunohistochemical features of lower intestinal tract-type mucinous tumors may be teratomatous in origin. In practice, the more common diagnosis of secondary involvement by a lower intestinal tract mucinous tumor should be addressed in the pathology report and in subsequent clinical evaluation; interpretation as a true primary ovarian mucinous tumor of teratomatous origin can be considered as an alternative diagnosis when evaluation and follow-up fail to identify a nonovarian source of the mucinous tumor. Those tumors having CK7 expression with or without CK20 expression may be derived from upper gastrointestinal tract-type or sinonasal-type teratomatous elements but could be independent tumors of surface epithelial-stromal origin.

Distinction of primary ovarian epithelial tumors from metastatic adenocarcinomas is challenging for tumors exhibiting mucinous, endometrioid, or mixed endometrioid/mucinous differentiation. Metastatic carcinomas with these types of differentiation can be derived from several sites, including the gastrointestinal tract and the uterus. Most endocervical adenocarcinomas exhibit mucinous and/or endometrioid differentiation; they infrequently metastasize to the ovaries but may simulate primary ovarian tumors [both atypical proliferative (borderline) and carcinoma]. Most are high-risk human papillomavirus (HPV)-related and demonstrate diffuse p16 over-expression due to complex molecular mechanisms by which high-risk HPV transforming proteins interact with cell cycle regulatory proteins. The performance of this expression pattern for identifying metastatic endocervical adenocarcinomas in the ovaries among primary ovarian tumors and other metastatic adenocarcinomas having mucinous and/or endometrioid/endometrioidlike differentiation has not been evaluated. Immunohistochemical expression of p16 was assessed in 195 tumors, including 98 primary ovarian tumors (51 mucinous, 47 endometrioid, and 4 mixed mucinous-endometrioid tumors), 93 metastatic adenocarcinomas of known primary sites (colorectum: 34, endocervix: 19, pancreaticobiliary tract: 17, appendix: 7, stomach: 5), 11 metastatic adenocarcinomas of unknown origin (7 established as noncervical), and 4 adenocarcinomas of uncertain (primary ovarian vs. metastatic) origin. The HPV status of the endocervical adenocarcinomas was determined by in situ hybridization and polymerase chain reaction (when in situ hybridization was negative). Expression was assessed based on the percentage of moderately to strongly positive cells, estimated to the nearest 10%. Mean and median expression values for HPV-positive endocervical adenocarcinomas (99%, 100%; range 90% to 100%) were substantially higher than those for primary ovarian mucinous (5%, 0%; range 0% to 70%) and endometrioid (20%, 10%; range 0% to 100%) tumors, HPV-unrelated endocervical adenocarcinomas (0%, 0%; range 0% to 60%), metastatic adenocarcinomas of unknown origin (11%, 0%; range 0% to 30%), and adenocarcinomas of uncertain (primary ovarian vs. metastatic) origin (40%, 35%; range 0% to 90%); only the 15 HPV-positive endocervical adenocarcinomas and 6 other tumors had values of 80% or greater. Diffuse (>75% positive tumor cells) moderate to strong p16 expression is a sensitive (100%) and specific (97%) marker for identifying HPV-related endocervical adenocarcinomas metastatic to the ovary among the primary ovarian tumors and metastatic adenocarcinomas from other sites that are in the differential diagnosis of ovarian tumors having mucinous and/or endometrioid/endometrioidlike differentiation. p16 is useful as part of a panel of immunohistochemical markers for distinguishing primary ovarian tumors from metastases and, when diffusely positive, can suggest the cervix as a potential primary site for metastatic adenocarcinomas of unknown origin.

Recent studies have demonstrated conflicting results regarding the value of CDX2 for distinguishing primary ovarian mucinous tumors from metastatic mucinous carcinomas in the ovary. Utility of coordinate expression of cytokeratins 7 and 20 is restricted to distinction of ovarian mucinous tumors from lower gastrointestinal tract metastases and data comparing coordinate expression of all three markers is limited. Immunohistochemical studies were performed to compare expression of CDX2 and cytokeratin 20, both markers of intestinal differentiation, in conjunction with coordinate expression of cytokeratin 7, in 90 mucinous tumors involving the ovary: 42 primary ovarian mucinous tumors (31 atypical proliferative (borderline) mucinous tumors (gastrointestinal type), 11 mucinous carcinomas) and 48 metastatic mucinous carcinomas of upper (pancreaticobiliary tract: 14; stomach: five) and lower (colon and rectum: 25; appendix: four) gastrointestinal tract origin. Primary ovarian tumors expressed CDX2 (40%) less frequently than cytokeratin 20 (83%) (P<0.0001). CDX2 expression in primary ovarian tumors (40%) was lower than CDX2 expression in metastatic carcinomas of both upper (74%; P=0.016) and lower gastrointestinal tract origin (90%; P<0.0001). Cytokeratin 20 expression was similar in primary ovarian tumors (83%) and metastases of upper (89%; P=0.071) and lower gastrointestinal tract origin (93%; P=0.29). Thus, as a single marker CDX2 offers some advantage over cytokeratin 20 because it is less frequently positive in primary ovarian tumors. In the almost universally cytokeratin 7-positive primary ovarian tumors and metastases of upper gastrointestinal tract origin, CDX2 coordinate expression was less common in primary ovarian tumors (36%) than in metastases of upper gastrointestinal tract origin (63%) (P=0.022) whereas cytokeratin 20 coordinate expression was identical in both tumor types (79%). In the almost universally cytokeratin 7-negative metastases of lower gastrointestinal tract origin, coordinate expression of CDX2 (83%) and cytokeratin 20 (86%) were equivalent (P=1.00). CDX2 was comparable to cytokeratin 20 in distinguishing metastases of lower gastrointestinal tract origin (usually cytokeratin 7-negative and CDX2/cytokeratin 20 positive) from primary ovarian tumors and metastases of upper gastrointestinal tract origin (usually cytokeratin 7-positive and CDX2/cytokeratin 20 variable). CDX2 provided some advantage over cytokeratin 20 for distinguishing primary ovarian mucinous tumors from metastases of upper but not lower gastrointestinal tract origin; however, the advantage in the former was limited due to the occurrence of shared coordinate expression profiles in both tumor types. Cytokeratin 7 provides the predominant discriminatory value among these markers yet is limited to distinction of primary ovarian tumors from metastases of lower gastrointestinal tract origin.

Coordinate expression profiles for cytokeratins 7 and 20 (CK7 and CK20) are useful for distinguishing certain types of adenocarcinomas but use for distinction of primary and secondary mucinous tumors in the ovary is limited due to the existence of a number of tumor types exhibiting overlapping CK7/CK20 immunoprofiles; the use of staining distribution patterns in the distinction of tumors with shared profiles has not been evaluated in detail. We report analysis of both coordinate expression profiles and staining distribution in 179 rigorously classified mucinous tumors in the ovary, including 53 primary tumors [35 atypical proliferative (borderline) mucinous tumors of gastrointestinal type and 18 invasive mucinous carcinomas] and 126 secondary tumors [28 colorectal adenocarcinomas, 54 appendiceal tumors (23 adenocarcinomas, 31 low-grade adenomatous mucinous tumors associated with pseudomyxoma peritonei), 14 pancreatic adenocarcinomas, 8 endocervical adenocarcinomas, 5 gastric adenocarcinomas, 4 gallbladder/biliary tract adenocarcinomas, and 13 adenocarcinomas of unknown primary sites). A CK7+/CK20+ immunoprofile was the most common profile in primary ovarian tumors (74%), upper gastrointestinal tract tumors (78%), and endocervical tumors (88%) but was occasionally observed in lower intestinal tract tumors (colorectal: 11%; appendiceal: 13% of low-grade tumors, 35% of carcinomas). A CK7-/CK20+ immunoprofile was the most common profile in lower intestinal tract tumors (79%) and was uncommon in upper gastrointestinal tract tumors (9%), rarely seen in primary ovarian tumors (4%), and not seen in endocervical tumors. A CK7+/CK20- profile was observed in some primary ovarian (23%), upper gastrointestinal tract (13%), and endocervical tumors (13%) but not in lower intestinal tract tumors. For CK7+ tumors, staining distribution was very frequently diffuse (>50% of tumors cells positive) in primary ovarian, upper gastrointestinal tract, and endocervical tumors, whereas staining distribution was often focal (<50% of tumors cells positive) when present in colorectal and appendiceal carcinomas but not in low-grade appendiceal tumors. For CK20+ tumors, staining distribution was variable but often focal in primary ovarian tumors and nonlower intestinal tract tumors, whereas the pattern was almost always diffuse in lower intestinal tract tumors. Immunohistochemical staining distribution can supplement CK7/CK20 coordinate expression profiles to distinguish subsets of primary ovarian and metastatic lower intestinal tract mucinous tumors having overlapping immunoprofiles but neither coordinate expression profiles nor staining distribution distinguishes primary ovarian tumors from the nonlower intestinal tract metastases.

Ovarian atypical proliferative (borderline) mucinous tumors of gastrointestinal and seromucinous types are considered subtypes within the mucinous tumor category despite the presence of distinctive clinicopathologic features that seromucinous tumors share with pure serous tumors. Immunophenotypic differences have not been extensively investigated. Immunohistochemical studies were performed to compare the expression patterns of cytokeratins 7 and 20 (CK7, CK 20), estrogen and progesterone receptors (ER, PR), CA-125, mesothelin, and WT-1 in 28 tumors of gastrointestinal type and 12 tumors of seromucinous type. Both gastrointestinal and seromucinous type tumors had a high frequency of CK7 expression (93% and 100%, respectively). The gastrointestinal type tumors were characterized by frequent expression of CK20 (86%) and CDX2 (39%), infrequent expression of CA-125 (11%) and mesothelin (7%), and lack of expression of ER, PR, and WT-1. In contrast, the seromucinous type tumors were characterized by frequent expression of ER (100%), PR (67%), CA-125 (92%), and mesothelin (83%), infrequent expression of WT-1 (8%), and lack of expression of CK20 and CDX2. The gastrointestinal and seromucinous types of atypical proliferative mucinous tumors are immunophenotypically distinctive tumors. The former are characterized by expression of markers of gastrointestinal-type differentiation (CK20 and CDX2), whereas the latter are characterized by expression of "müllerian-type" markers (ER, PR, CA-125, and mesothelin). Expression of the latter markers in the seromucinous tumors, which also are expressed in pure serous tumors, and lack of expression of gastrointestinal-type markers, combined with the clinicopathologic features these tumors share with pure serous tumors, support the concept that this subtype is more closely related to serous than gastrointestinal type mucinous tumors and justify the designation "seromucinous."

Estrogen (ER) and progesterone receptor (PR) expression in primary ovarian mucinous tumors and the utility of these markers for distinguishing metastatic mucinous carcinomas in the ovary from primary ovarian mucinous tumors have not been extensively investigated. Immunohistochemical studies were performed on 124 mucinous tumors, including 52 primary ovarian tumors (30 atypical proliferative (borderline) mucinous tumors of gastrointestinal type, 11 atypical proliferative (borderline) mucinous tumors of seromucinous (endocervical-like) type, and 11 invasive mucinous carcinomas of usual (gastrointestinal) type) and 72 metastatic mucinous carcinomas in the ovary (primary sites: colorectum (24), pancreas (13), endocervix (eight), stomach (four), gallbladder/bile duct (four), appendix (four), and unknown (15)). All atypical proliferative mucinous tumors of gastrointestinal type, primary ovarian mucinous carcinomas, and metastatic mucinous carcinomas were negative for ER and PR with the exception of three metastatic endocervical adenocarcinomas which exhibited only weak expression of ER without PR. All atypical proliferative mucinous tumors of seromucinous type expressed ER to some degree and seven had some expression of PR. Immunohistochemical assessment of hormone receptor expression is of no value in distinguishing the common types of primary ovarian mucinous tumors (atypical proliferative mucinous tumors of gastrointestinal type and mucinous carcinomas of usual type) from the vast majority of mucinous carcinomas metastatic to the ovary. The above observations on hormone receptor expression in primary ovarian mucinous tumors support the concept that atypical proliferative (borderline) mucinous tumors of gastrointestinal and seromucinous (endocervical-like) types are distinctive tumors.

Carcinomas of ovarian surface epithelial origin can arise from, and often present at, extraovarian sites. There are few available markers for the positive identification of carcinomas of ovarian surface epithelial origin, which might aid in distinguishing them from metastatic carcinomas, such as of breast, colon, or lung origin. Recently, the Wilms tumor gene product (WT-1) has been shown to be expressed in ovarian surface and mesothelial epithelium. We tested the hypothesis that WT-1 would be a sensitive and specific marker of ovarian surface epithelium carcinomas. An archived series of 116 ovarian carcinomas (57 serous [43 ovarian, 14 extraovarian], 31 mucinous, 15 clear cell, 13 endometrioid), 118 breast carcinomas, 46 colonic carcinomas, and 45 nonsmall cell lung cancers were selected. A polyclonal antibody to the WT-1 gene product was applied to deparaffinized, formalin-fixed tissue sections after epitope retrieval. Fifty-two of 57 (93%) serous carcinomas of ovarian surface epithelial origin were WT-1-positive, in a nuclear pattern, with virtually all the tumor cell population positive in the majority of cases. None of the mucinous, clear cell, or endometrioid ovarian cancers were positive, and only 8 of 118 breast, 0 of 46 colonic, and 0 of 45 lung nonsmall cell carcinomas were WT-1-positive. These findings demonstrate that WT-1 is a highly sensitive and specific marker of serous carcinomas of ovarian surface epithelial origin (both ovarian and extraovarian). These results also contradict recent reports demonstrating WT-1 expression in both breast and lung carcinomas.