Unexpected PAX8 Immunoreactivity in Metastatic High-grade Breast Cancer.

Immunohistochemistry (IHC) is often critical for distinction between metastatic carcinomas of Mullerian organ and breast origin. Paired box family protein 8 (PAX8) has been described as a transcription factor highly specific to neoplasms derived from Mullerian organs, thyroid, and kidney. PAX8 IHC with polyclonal and monoclonal antibody reagents was performed on 27 primary and 22 metastatic breast carcinomas. Eight of 27 primary breast carcinomas (30%) were positive for PAX8 with the monoclonal antibody reagent only; 0 of 22 were polyclonal anti-PAX8 immunoreactive. Substantial numbers of metastases had positive immunoreactivity for polyclonal anti-PAX8 (23%). Each of these metastases and additional cases (45% total) also had positive immunoreactivity for monoclonal anti-PAX8, including 5 of 7 brain metastases. IHC with monoclonal anti-PAX8 was positive on 6 of 7 primary breast carcinomas corresponding to PAX8-positive metastases. Together, these results indicate a significant fraction of breast carcinoma metastases and corresponding primary neoplasms have immunoreactivity for PAX8, and positivity rates depend on the antibody used. Diagnoses of metastatic breast carcinoma were achieved with the aid of clinical history and additional IHC in cases of PAX8 immunoreactivity. Contextual interpretation is imperative for PAX8 IHC, particularly when the differential diagnosis includes metastatic breast carcinoma with limited diagnostic material available.

PD-L1 Expression in Carcinosarcomas of the Gynecologic Tract: A Potentially Actionable Biomarker.

BACKGROUND: Carcinosarcomas of the gynecologic tract, also known as malignant mixed Müllerian tumors, are aggressive neoplasms with a high recurrence rate and poor prognosis. Despite advances in adjuvant therapies in recent years, the prognosis of these tumors has not improved. In fact, there are currently no consensus guidelines for the treatment of these neoplasms and the search for targetable biomarkers has not been successful so far. Programmed death-ligand 1 (PD-L1) has emerged as a potential target for therapeutics in a number of malignant tumors, including melanoma, lung, and colorectal cancer. In normal conditions, PD-L1 is thought to promote immune homeostasis via a number of pathways, but mainly through downregulation of cytotoxic T cells. In some human neoplasms, however, overexpression of PD-L1 by tumor cells has been observed, which can modulate the immune system to allow cancer cells to evade host response. As this marker could potentially be a therapeutic target for these tumors, the immunohistochemical expression of PD-L1 in a group of carcinosarcomas was evaluated in the present study. MATERIAL AND METHODS: Twenty-nine cases of gynecologic carcinosarcomas were analyzed, corresponding to tumors originating from the uterus (25), ovary (2), fallopian tube (1), and pelvic epithelium (1). Immunohistochemistry for PD-L1 was performed on paraffin sections and the staining results were assessed semiquantitatively in both epithelial and mesenchymal components of each tumor. RESULTS: Positive membranous staining for PD-L1 was detected in 25/29 tumors (86%). The epithelial components were strongly positive in 19/29 (65%) and weakly positive in 6/29 tumors (21%). The mesenchymal elements were strongly positive in 8/29 (27%) and weakly positive in 3/29 tumors (10%). With exception of 1, all tumors with positive sarcomatous components had staining of the carcinomatous element. Four tumors were negative for PD-L1 in both components. CONCLUSIONS: This study shows that PD-L1 is expressed by the majority of carcinosarcomas, predominantly in the epithelial components. This is particularly important as most locoregional recurrences and distant metastases are of epithelial origin. This finding may serve as a basis for possible therapeutic approaches using antibodies that have already shown significant value in a number of other malignant tumors.

Uterine Carcinosarcomas: Clinical, Histopathologic and Immunohistochemical Characteristics.

Carcinosarcomas (malignant mixed Müllerian tumors or MMMT) are rare malignant tumors in the female genital tract composed of both malignant epithelial and malignant mesenchymal components. They comprise <5% of all neoplasms in the gynecologic tract and have an aggressive clinical course. The purpose of this study is to evaluate the immunophenotype and possible histogenesis of carcinosarcomas of the uterus. Sixty-two cases of uterine carcinosarcomas diagnosed between 1995 and 2011 were retrieved from the gynecologic pathology files at Columbia University Medical Center. Representative tissue blocks containing both epithelial and mesenchymal components were selected from each case for histologic and immunohistochemical studies. Clinical data from each case were retrieved. The epithelial component was poorly differentiated adenocarcinoma in the majority (80.7%) of cases; in 17.7%, the carcinoma was moderately differentiated, and in only 1.6% the carcinoma was well differentiated. 53% of the tumors had homologous stromal elements and 47% displayed heterologous stromal elements. Immunohistochemical study revealed almost equal staining in both epithelial and mesenchymal components of carcinosarcomas for p16 and p53. PAX8 positivity was noted in 73% of epithelial components, but only 13% of stromal components, and PAX8 stromal positivity was never seen in the absence of PAX8 epithelial positivity. Expression of p16, p53, and PAX8 in both malignant components lends support to the monoclonal theory of uterine carcinosarcoma tumorigenesis. The roles of these tumor markers in the diagnosis and pathogenesis of this tumor and associations between clinical characteristics, tumor pathologic features, and prognosis are discussed.

Uterine Adenosarcoma.

Müllerian adenosarcoma is an uncommon biphasic tumor composed of malignant stromal and benign epithelial components. Morphologically, adenosarcoma is characterized by a broad leaflike architecture, reminiscent of phyllodes tumors of the breast. Periglandular cuffing of the stromal cells around the compressed or cystically dilated glands is characteristic. The mesenchymal component is typically a low-grade spindle cell sarcoma, whereas the epithelial counterpart is commonly endometrioid with frequent squamous or mucinous metaplasia and may, in some circumstances, show mild to moderate atypia. In all cases, it is important to assess for the presence of sarcomatous overgrowth and myometrial invasion, which are the prognostic factors. In this brief review, we present the clinical, histopathologic, and immunohistochemical features of adenosarcoma, as well as updates on the molecular biology of this neoplasm.

GHRH Receptor Expression in Malignant Mixed Müllerian Tumors: A Potentially Targetable Biopredictor.

Malignant mixed Müllerian tumors (MMMTs) are aggressive malignant neoplasms with a high recurrence rate and poor prognosis. Despite advances in adjuvant therapies in recent years, the prognosis of these tumors has not improved. Growth hormone-releasing hormone (GHRH) is produced by a variety of malignant tumors and acts as a growth factor in an autocrine/paracrine manner. Its function requires the presence of its receptors to exert its effects on neoplastic cells. In this study, we evaluated the expression of GHRH receptors (GHRH-R) in a group of MMMTs. Thirty-one examples of MMMTs from endometrium, ovary, uterine tube, and pelvic peritoneum were retrieved from the files of Department of Pathology at the University of Miami, Jackson Memorial Hospital. Immunohistochemistry for GHRH-R was performed on paraffin sections and the staining results were evaluated separately in both epithelial and mesenchymal components of each tumor. The presence of pituitary type growth hormone-releasing hormone receptor mRNA and that of its biologically active splice variant were also evaluated by RT-PCR in 6 of the tumors. Positive immunohistochemical reaction for GHRH-R was detected in 30 tumors (96%). The epithelial and sarcomatous components were positive in 30 (96%), whereas one endometrial tumor was negative in both components. The mRNA for GHRH-R and its splice variant was found in all 6 tested tumors. This study shows that GHRH-R is expressed by the majority of MMMTs in both epithelial and mesenchymal components. This finding could potentially serve as a basis for therapeutic approaches using synthetic peptide antagonists of GHRH-R that have shown significant efficacy with minimal side effects in experimental models.

Epithelial-to-mesenchymal transition and stem cells in endometrial cancer.

This review article describes the main features of epithelial-to-mesenchymal transition (EMT) and its possible role in understanding myometrial invasion in endometrial carcinoma (EC), as well as the development of malignant mixed Müllerian tumor (MMMT). Moreover, the article discusses the possible role of somatic (SSC) and cancer stem cells (CSC) in EC. Different transcriptional repressors of E-cadherin have been identified in EMT, including Snail and Slug, ZEB1 and ZEB2, and E47 and Twist. The expression of some of these genes is increased at the myoinvasive front and correlates inversely with E-cadherin inmunoreactivity. Whereas the transient occurrence of the EMT phenomenon is important for myometrial invasion in conventional EC, MMMT shows permanent expression of EMT leading to repression of E-cadherin and increased expression of mesenchymal markers including proteins involved in skeletal muscle development. An SSC population, identified as a side population, assessed by the Hoechst dye exclusion test has been identified in human endometrium. CSCs have been defined in analogy to SSC as cancer cells that have the capacity to self-renew, which means undergoing divisions that allow the generation of more identical CSCs and give rise to the variety of more differentiated cells found in the malignancy. Although published data show that CD133(+) cells retain the characteristics of CSC, there is no conclusive evidence showing that CD133 is the universal marker for EC stem cells. Finally, a possible role for endometrial stem cells in the development of ovarian endometriosis and ovarian endometrioid carcinoma is commented.

Ovarian carcinosarcoma associated with bilateral tubal intraepithelial carcinoma: a case report.

Carcinosarcomas (malignant mixed müllerian tumors) of the ovary are rare tumors. This report describes a case of a 64 years old patient presenting with a large tumor in the true pelvis, intraoperatively originating from the right ovary, with peritoneal metastatic deposits. Histologically, a dominant sarcomatoid component consisted of short spindle and epithelioid round cells. The nuclei were round to oval, with pleomorphism, hyperchromasia and frequently conspicuous nucleoli. Mitotic activity was brisk. The cells were aligned in hypercellular to myxoid hypocellular arrangements. Large epithelioid cells displayed abundant deeply eosinophilic cytoplasm and mono- to multinucleation. Immunohistochemically, these cells displayed strong reactivities for desmin, WT1 in a cytoplasmic staining pattern, p16, and vimentin. A second and minor tumor component revealed epithelial differentiation with mixed serous- endometrioid and squamous features, and immunohistochemical staining for AE1/AE3 cytokeratin, focally for p16 and p53(ink4), for nuclear WT1 in varying quantities, and weakly for vimentin. The fallopian tubes were remarkable for circumscribed areas of serous tubal intraepithelial carcinoma (STIC), found at the fimbria of the right and in the tubal mucosa close to the fimbria of the left tube. The final diagnosis was carcinosarcoma of the right ovary (malignant müllerian mixed tumor, heterologous type), with rhabdomyosarcomatous differentiations, FIGO stage IIIC. The patient died of recurrent tumor seven month after primary presentation.

The vaginal spindle cell epithelioma: a case report, review of the literature and discussion of potential histogenesis.

The so-called mixed tumors occur in a variety of sites throughout the body. While most cases are encountered in the salivary glands, several cases have been described in the female genital tract. A variety of monikers have been applied to this lesion including "spindle cell epithelioma." As in other locations, the vaginal spindle cell epithelioma (VSE) consists of a proliferation of both epithelial and mesenchymal components. Based on our extensive review of the literature, we present the 53rd reported case of VSE. More significantly, we present the most up-to-date review of this lesion, including its immunohistochemical and electron microscopic features. We also review the theories pertaining to its histogenesis incorporating current embryologic data, which together suggest a Müllerian derivation.

PAX2 and PAX8 expression in primary and metastatic müllerian epithelial tumors: a comprehensive comparison.

PAX2 and PAX8 are transcription factors that are essential in embryonic development of müllerian organs. They may also play a role in tumor development in these organs. The diagnostic utility of PAX2 and PAX8 relative to one another has not been comprehensively studied. Archival tissue samples for normal or non-neoplastic tissue (251), primary epithelial neoplasms (316 for PAX2 and 357 for PAX8), and metastatic epithelial neoplasms (16), all of müllerian origin, were subjected to PAX2 and PAX8 immunostaining. The staining frequency, extent, and intensity for these markers were compared. Virtually identical PAX2 and PAX8 expressions were noted in non-neoplastic tissue. They were constantly seen in most epithelial cells (but not in stromal cells) of the endocervix, endometrium, fallopian tube, paratubal cyst, endosalpingiosis, endometriosis, and endometrial polyp. Within the primary epithelial neoplasms, PAX2 and PAX8 expression was noted in 55% and 98% of serous tumors, 25% and 94% of endometrioid tumors, 19% and 100% of clear cell tumors, 11% and 67% of transitional/undifferentiated tumors, and 10% and 22% of mucinous tumors, respectively. Regardless of histologic subtypes, PAX2 staining was noted in fewer cells and with less staining intensity compared with PAX8. No tumor showed only PAX2 staining. Within the metastatic carcinomas, PAX2 and PAX8 expression was noted in 38% and 98% of cases, respectively, with a diffuse and strong staining for PAX8, contrasting with a patchy and weak PAX2 expression. PAX2 and PAX8 are constantly expressed in normal or non-neoplastic tissue of müllerian origin. For primary and metastatic müllerian epithelial tumors, PAX8 shows strong and diffuse staining in most cases of all histologic subtypes, except in mucinous tumors. In contrast, PAX2 expression is always less than PAX8, and exclusive staining for PAX2 is not seen. PAX8 supersedes PAX2 as probably the best epithelial marker hitherto for primary or metastatic müllerian epithelial tumors.

CD133+ cancer stem cell-like cells derived from uterine carcinosarcoma (malignant mixed Müllerian tumor).

Cancer stem cells (CSCs) that display tumor-initiating properties have recently been identified. CD133, a surface glycoprotein linked to organ-specific stem cells, has been described as a marker of CSCs in different tumor types. We herein identify and characterize CSCs in human uterine carcinosarcoma (malignant mixed Müllerian tumor), which is one of the most aggressive and therapy-resistant gynecological malignancies and is considered to be of mesodermal origin. The CD133(+) population was increased in uterine carcinosarcoma, and this population showed biphasic properties in the primary tumor. CD133(+) cells predominantly formed spheres in culture and were able to differentiate into mesenchymal lineages. CD133(+) cells were more resistant to cisplatin/paclitaxel-induced cytotoxicity in comparison with CD133(-) cells. A real-time polymerase chain reaction analysis of the genes implicated in stem cell maintenance revealed that CD133(+) cells express significantly higher levels of Oct4, Nanog, Sox2, and Bmi1 than CD133(-) cells. Moreover, CD133(+) cells showed a high expression level of Pax2 and Wnt4, which are genes essential for Müllerian duct formation. These CD133(+) cells form serially transplantable tumors in vivo and the resulting CD133(+) tumors replicated the EpCAM, vimentin, and estrogen and progesterone receptor expression of the parent tumor, indicating that CSCs likely differentiated into cells comprising the uterine carcinosarcoma tissue. Moreover, strong CD133 expression in both epithelial and mesenchymal elements in primary tumor demonstrated significant prognostic value. These findings suggest that CD133(+) cells have the characteristics of CSCs and Müllerian mesenchymal progenitors.

Primary malignant mixed müllerian tumor of the peritoneum a case report with review of the literature.

Malignant mixed Müllerian tumor is a rare malignancy of the genital tract and extremely uncommon in extragenital sites. This report describes a case of malignant mixed Müllerian tumor arising in the lower peritoneum of a 72-year-old female patient. The patient presented with ascites, lower abdominal mass and pleural effusion. The serum level of CA125 was elevated. At operation a diffuse carcinosis associated with tumor mass measuring 20 × 15 × 10 cm in the vesicouterine and Duglas' pouch were found. The uterus and the adnexa were unremarkable. Histopathology revealed a typical malignant mixed Müllerian tumor, heterologous type. The epithelial component was positive for cytokeratin 7 and vimentin whereas the mesenchymal component was positive for Vimentin, S100 and focally for CK7. The histogenesis of this tumor arising from the peritoneum is still speculative. Based on the previous reports and the immunohistochemical analysis of our case, we believe that this is a monoclonal tumor with carcinoma being the "precursor" element. Nevertheless, further molecular and genetic evidence is needed to support such a conclusion.

Malignant melanoma arising in an ovarian carcinosarcoma: case report and review of the literature.

A case of ovarian malignant mixed mullerian tumor (MMMT) with melanocytic differentiation is described. A 74-year-old woman presented with left lower quadrant pain. Pathologic examination of the left ovary revealed a MMMT, composed predominantly of serous carcinoma (90%) with a minor sarcoma component containing focal chondroid differentiation. There was also a single focus of malignant melanoma. Immunohistochemical studies showed that the latter was positive for S-100, HMB-45, and pan-melanoma cocktail, and was negative for synaptophysin and neuron-specific enolase. To the best of our knowledge, this is the first case of MMMT with melanocytic differentiation described in the ovary.

The morphologic spectrum of uterine PEC-cell associated tumors in a patient with tuberous sclerosis.

Perivascular epithelioid cell (PEC) neoplasms are an unusual group of mesenchymal tumors thought to arise from the PEC, which characteristically expresses melanocytic markers with common coexpression of muscle markers. They show a wide morphologic spectrum and have been described in multiple anatomical locations, including the uterus. We report a 59-year-old woman with tuberous sclerosis, initially diagnosed with a uterine malignant mixed müllerian tumor, in whom the hysterectomy specimen also showed 3 other incidental tumors: a subserosal angiomyolipoma consisting of blood vessels of varying caliber, mature adipose tissue, and nests of spindle cells arranged in a perivascular location, a sclerosing PEComa consisting of small nests of clear epithelioid cells present in a background of marked sclerosis centered in the lower uterine segment/endocervix, and diffuse lymphangiomyomatosis involving the endocervix, lower uterine segment, and uterine corpus. This case provides further evidence of a common precursor cell of origin for these lesions.

Netrin-4 is upregulated in breast carcinoma effusions compared to corresponding solid tumors.

We recently identified overexpression of the NTN4 gene in breast carcinoma effusions compared to primary carcinomas using gene-expression arrays. The objective of this study was to validate this finding at protein level and analyze the clinical role of Netrin-4 in breast carcinoma effusions. We additionally studied Netrin-4 expression and its clinical relevance in Müllerian (ovarian, peritoneal, and tubal) carcinoma effusions. Sections from 82 breast carcinomas (53 effusions and 29 solid tumors) and 57 Müllerian carcinoma effusions were stained for Netrin-4 using immunohistochemistry. Immunoreactivity was scored in carcinoma cells and analyzed for association with clinicopathologic parameters, including survival. In breast carcinoma, expression of Netrin-4 was detected in carcinoma cells in 30/53 (57%) effusions compared to 3/29 (10%) solid tumors (P < 0.001). Netrin-4 was further expressed in 31/57 (54%) Müllerian carcinoma effusions. No association was found between Netrin-4 expression in breast or Müllerian carcinoma effusions and clinicopathologic parameters, including survival. Our data provide validation on protein level of upregulated Netrin-4 expression in breast carcinoma effusions. The frequent expression of Netrin-4 in Müllerian carcinoma effusions suggests a biological role for this molecule in metastases from gynecological malignancies. Netrin-4 expression in effusions does not appear to be a predictor of disease outcome.

Pax8: a marker for carcinoma of Müllerian origin in serous effusions.

PAX8 is a nuclear transcription factor with limited expression in normal and neoplastic tissues in a cell lineage-dependent manner. PAX8 has been detected in embryonic Müllerian ducts, human fallopian tubes, and ovarian carcinomas. However, little is known about its expression in other areas of the female genital tract. In this study, we used immunohistochemistry (IHC) to examine PAX8 expression in the normal uterine corpus and cervix, malignant tumors arising from these sites, and malignant effusions. We reported here that PAX8 was also detected in endometrial epithelial cells and endocervical glands, with a lower expression level in the latter, but not in the stromal cells of these areas. All endometrial carcinomas (N = 52) were positive for PAX8, whereas endocervical adenocarcinomas (N = 5) and uterine leiomyosarcomas (N = 3) were negative for PAX8. PAX8 was detected in 70% (22/31) and 68.8% (11/16) of metastatic carcinomas of the ovary and endometrium in serous effusions, respectively. No PAX8 was detected in carcinomas of nongynecologic origin or noncarcinomas (N = 71) in serous effusions except in one renal-cell carcinoma and one carcinoma of unknown primary in a woman. In addition, papillary serous carcinomas of the peritoneum (N = 10) were diffusely positive for PAX8, implying a Müllerian origin similar to malignant tumors in the female genital tract. Our findings suggest that PAX8 is an additional IHC marker for carcinomas of Müllerian origin hence we recommend including PAX8 for evaluation of malignant serous effusions in women, especially when tumors of Müllerian origin are in the differential diagnosis.

WT1 immunoprofiling and comparison of malignant Mullerian mixed tumors of the female genital tract.

A malignant Mullerian mixed tumor (MMMT) is a biphasic homologous or heterologous malignancy of the female genital tract. WT1 (Wilms tumor 1) is both a tumor suppressor gene and oncogene overexpressed in the nuclei of some gynecologic carcinomas. Expression in MMMT is incompletely described. Whole sections from 16 MMMTs were stained with WT1 (N terminus) using a standard immunoperoxidase technique. There were 7 heterologous and 9 homologous tumors and 10 were endometrial, 5 were ovarian, and 1 was of peritoneal origin. The tissue and cell staining pattern and score (intensity by amount) were evaluated and correlated with the tumor subtype and anatomic location. Among the 16 tumors, 81.3% showed mostly stromal and cytoplasmic staining and a score of 3 or 6. Staining was positive in 80% of the endometrial and ovarian tumors and the 1 peritoneal tumor and in all heterologous and 66.7% of the homologous tumors. The immunoprofile correlated with tumor subtype but not with anatomic location. Stromal and epithelial staining was more frequent (83.3%) in homologous tumors and differed significantly (P=0.009) from the heterologous types where stromal staining prevailed (85.7%). MMMT is another genital tract malignancy which can over express WT1 and the immunoprofile may assist in tumor subtyping.

Malignant mixed Mullerian tumors of the uterus: histopathological evaluation of cell cycle and apoptotic regulatory proteins.

AIM: The aim of our study was to evaluate survival outcomes in malignant mixed Mullerian tumors (MMMT) of the uterus with respect to the role of cell cycle and apoptotic regulatory proteins in the carcinomatous and sarcomatous components. METHODS: 23 cases of uterine MMMT identified from the Saskatchewan Cancer Agency (1970-1999) were evaluated. Immunohistochemical expression of Bad, Mcl-1, bcl-x, bak, mdm2, bax, p16, p21, p53, p27, EMA, Bcl-2, Ki67 and PCNA was correlated with clinico-pathological data including survival outcomes. RESULTS: Histopathological examination confirmed malignant epithelial component with homologous (12 cases) and heterologous (11 cases) sarcomatous elements. P53 was strongly expressed (70-95%) in 15 cases and negative in 5 cases. The average survival in the p53+ve cases was 3.56 years as opposed to 8.94 years in p53-ve cases. Overexpression of p16 and Mcl-1 were observed in patients with longer survival outcomes (>2 years). P16 and p21 were overexpressed in the carcinomatous and sarcomatous elements respectively. Cyclin-D1 was focally expressed only in the carcinomatous elements. CONCLUSIONS: Our study supports that a) cell cycle and apoptotic regulatory protein dysregulation is an important pathway for tumorigenesis and b) p53 is an important immunoprognostic marker in MMMT of the uterus.

Comparative analysis of P16 and P53 expression in uterine malignant mixed mullerian tumors.

Recent studies have shown that, in addition to cervical carcinomas, a substantial proportion of endometrial adenocarcinomas are also immunoreactive with p16. The expression of p16 in uterine malignant mixed mullerian tumors (MMMTs), in contrast, has not yet been analyzed in a large series. To our knowledge, we present the first study assessing p16 expression in both components of MMMTs. We performed p16 and p53 immunostains on 30 cases of uterine MMMTs. Both the epithelial and mesenchymal components were subclassified; p16 and p53 immunoreactions were assessed using a semiquantitative scoring system. p16 overexpression was noted in the carcinomatous component in 96.7% (29/30), and in the sarcomatous component in 86.7% (26/30) of cases. In comparison, p53 immunoreactivity was present in the carcinomatous component in 76.7% (23/30), and in the sarcomatous component in 83.3% (25/30) of cases. p16 immunoreactivity was more intense and diffuse than p53 in 40% of type I, 30% of type II carcinomas, and 27% of sarcomatous components. There was no significant difference in p16 or p53 immunoreactivity between the homologous and heterologous sarcomas. The concordance rates for p16 and p53 immunoreactivity between the 2 components were 83% and 90%, respectively. We conclude that p16 immunostain is positive in the vast majority of uterine MMMTs with no significant difference in staining between the 2 components. Compared with p53, p16 immunoreactivity is significantly more intense and diffuse in both components. Our findings indicate that alterations in the p16-Rb pathway play an important role in the pathogenesis of uterine MMMTs.