CD10 expression in epithelial tissues and tumors of the gynecologic tract: a useful marker in the diagnosis of mesonephric, trophoblastic, and clear cell tumors

CD10 Expression Correlates with Earlier Tumour Stages and Left-Sided Tumour Location in Colorectal Cancer but Has No Prognostic Impact in a European Cohort

The role of CD10 expression in colorectal cancer has been controversially discussed in the literature. Some data suggest a predictive capacity for lymph node and liver metastases, thus influencing overall survival (OS) and disease-free survival (DFS). This study aims to analyse the relationship between CD10 expression and overall survival (OS) in a European cohort. To determine the association of CD10 expression with tumour phenotype, molecular features, and prognosis, a tissue microarray of 1469 colorectal carcinomas was analysed using immunohistochemistry and was compared with matched clinicopathologic data. CD10 expression correlated with earlier tumour stages (p = 0.017) and left-sided colon cancer (p < 0.001). However, no correlation was found between CD10 expression and lymph node involvement (p = 0.711), tumour grading (p = 0.397), or overall survival (p = 0.562). Even in the subgroup analysis of tumour or nodal stage, CD10 did not affect overall survival, although it was significantly associated with p53 and nuclear β-catenin expression (p = 0.013 and p < 0.001, respectively). CD10 expression correlates with earlier tumour stages, colon cancer location, and indicators of aggressive CRC subtypes. However, we can exclude CD10 as a relevant independent prognosticator for CRC.

A comprehensive review of the literature on CD10: its function, clinical application, and prospects

CD10, a zinc-dependent metalloprotease found on the cell surface, plays a pivotal role in an array of physiological and pathological processes including cardiovascular regulation, immune function, fetal development, pain response, oncogenesis, and aging. Recognized as a biomarker for hematopoietic and tissue stem cells, CD10 has garnered attention for its prognostic potential in the progression of leukemia and various solid tumors. Recent studies underscore its regulatory significance and therapeutic promise in combating Alzheimer's disease (AD), and it is noted for its protective role in preventing heart failure (HF), obesity, and type-2 diabetes. Furthermore, CD10/substance P interaction has also been shown to contribute to the pain signaling regulation and immunomodulation in diseases such as complex regional pain syndrome (CRPS) and osteoarthritis (OA). The emergence of COVID-19 has sparked interest in CD10's involvement in the disease's pathogenesis. Given its association with multiple disease states, CD10 is a prime therapeutic target; inhibitors targeting CD10 are now being advanced as therapeutic agents. This review compiles recent and earlier literature on CD10, elucidating its physicochemical attributes, tissue-specific expression, and molecular functions. Furthermore, it details the association of CD10 with various diseases and the clinical advancements of its inhibitors, providing a comprehensive overview of its growing significance in medical research.

Histological Variants of Squamous and Basal Cell Carcinoma in Squamates and Chelonians: A Comprehensive Classification

In the present study, the histological characteristics of squamous cell carcinomas (SCCs) and basal cell carcinomas (BCCs) obtained from 22 squamate and 13 chelonian species were retrospectively evaluated. While the examined tissues were originally diagnosed as 28 SCCs and 7 BCCs based on histological evaluation by a specialty diagnostic service, eight SCCs could be re-classified as BCCs and three SCCs proved to be non-neoplastic lesions. In addition, all SCCs and BCCs were classified into distinct histological variants. The SCCs could be categorized as one SCC in situ, three moderately differentiated SCCs, seven well-differentiated SCCs, and six keratoacanthomas. BCCs were classified as five solid BCCs, four infiltrating BCCs, five keratotic BCCs, and one basosquamous cell carcinoma. In addition, the present study reports the occurrence of BCCs in seven reptile species for the first time. In contrast to what has been documented in humans, IHC staining with the commercially available epithelial membrane antigen and epithelial antigen clone Ber-EP4 does not allow differentiation of SCCs from BCCs in reptiles, while cyclooxygenase-2 and E-cadherin staining seem to have discriminating potential. Although the gross pathological features of the examined SCCs and BCCs were highly similar, each tumor could be unequivocally assigned to a distinct histological variant according to the observed histological characteristics. Based on the results of this study, a histopathological classification for SCCs and BCCs is proposed, allowing accurate identification and differentiation of SCCs and BCCs and their histological variants in the examined reptile species. Presumably, BCCs are severely underdiagnosed in squamates and chelonians.

A Rare Case of Cutaneous Metastasis of Renal Cell Carcinoma to the Lateral Thigh

Renal cell carcinoma (RCC) is a common cancer type in the United States, and at the time of diagnosis, many patients already have metastatic disease. RCC typically metastasizes to the lungs, liver, and bones, with few cases manifesting cutaneous metastasis. Most incidences of RCC metastases reported in the literature have been on the face and scalp. We discuss a case of a 64-year-old male patient who presented with a history of RCC and a purpuric nodule on his lateral thigh. Histopathological examination revealed vacuolated cytoplasm with areas of cytoplasmic clearing; the cells stained positively for cytokeratin AE1/AE3, CAM5.2, and PAX8. Cutaneous metastatic RCC was subsequently diagnosed. Cutaneous manifestations of RCC, particularly to the thigh, remain a rare presentation of metastatic RCC.

Mesonephric-like Endometrial Carcinoma: Results From Immunohistochemical Screening of 300 Endometrial Carcinomas and Carcinosarcomas for This Often Overlooked and Potentially Aggressive Entity

Mesonephric-like endometrial carcinoma is a rare but frequently misclassified and aggressive malignancy. KRAS mutations, limited estrogen receptor (ER) expression, and TTF-1, GATA3, and luminal CD10 expression are described in these tumors, but an immunohistochemistry-based screening approach has not been studied. We assessed 300 endometrial carcinomas/carcinosarcomas to ascertain the specificity of TTF-1/GATA3/luminal CD10 expression with or without ER staining for this diagnosis. Next-generation sequencing and morphologic review were performed on screen-positive cases. In all, 3% (9/300) were TTF-1+; 2 coexpressed GATA3. No cases expressed luminal CD10 or GATA3 in isolation. Two TTF-1+/ER- cases, one of which was also GATA3+, were reclassified as mesonephric-like based on morphology and molecular results (KRAS mutations without mismatch repair deficiency, TP53 mutations, or PTEN mutations): these represented 0.7% of all cases (2/300). The reclassified cases were originally diagnosed as grade 1 and 2 endometrioid carcinoma, and the latter had pulmonary metastases and pelvic recurrences. Six TTF-1+ cases retained their original serous (3) and endometrioid (3) diagnoses; 1 was reclassified as dedifferentiated. All had negative or low ER. KRAS mutations were identified in 4 TTF-1+ non-mesonephric-like cases, including 1 serous and 1 grade 3 endometrioid with p53 abnormalities, 1 mismatch repair-deficient endometrioid with a complex molecular profile, and 1 endometrioid with mucinous differentiation. These findings suggest that TTF-1 and ER are good first-line screens for mesonephric-like carcinoma, but caution that a TTF-1+/ER- immunoprofile is not specific, even in the setting of KRAS mutations. A final diagnosis of mesonephric-like carcinoma requires integration of morphologic and immunohistochemical features, with molecular support when relevant.

Mesonephric-like Adenocarcinoma of the Female Genital Tract: From Morphologic Observations to a Well-characterized Carcinoma With Aggressive Clinical Behavior

Mesonephric-like adenocarcinoma (MLA) was introduced as a new tumor type in the endometrium and the ovary in the 2020 World Health Organization (WHO) Classification. This is a rare recently described (2016) and clinically aggressive carcinoma with a propensity for distant spread, especially to the lungs. MLA has a characteristic morphology and immunophenotype (hormone receptor negative; TTF1 and/or GATA3 positive). These neoplasms are commonly associated with KRAS and PIK3CA mutations and in the Cancer Genome Atlas (TCGA) molecular classification of endometrial carcinomas fall into the copy number low/no specific molecular profile category. Although they show significant morphological, immunophenotypic and molecular overlap with cervical mesonephric adenocarcinomas, there are other parameters which suggest a Mullerian origin and, as such, the term MLA seems apt. MLA can be added to the list of endometriosis-associated ovarian neoplasms. In this paper, I outline the series of events which lead to the first description of MLA and review the subsequent literature on this tumor type which has expanded on the morphologic features and immunophenotype, discovered the molecular underpinnings and elucidated the clinical behavior. The discovery of MLA represents an example of "new" entities still to this day being discovered through careful morphologic observations and referral of cases for specialist opinion.

The complex and often confusing history, histology and histogenesis of mesonephric, STK11 adnexal tumour and mesonephric-like neoplasms of the upper female genital tract (including broad ligament)

Mesonephric lesions in the female genital tract are uncommon, with those arising from the upper tract being much less frequent than those developing in the lower tract (mesonephric hyperplasia and carcinoma). The most common upper tract lesions include rete cyst/cystadenoma and female adnexal tumour of Wolffian origin (FATWO). The integration of morphological, immunohistochemical and molecular studies on FATWOs has enabled recognition of a novel entity, the STK11 adnexal tumour, which is often associated with Peutz-Jeghers syndrome (~50%) and frequently has a salivary gland morphology but an unknown origin. Similarly, 'mesonephric-like' adenocarcinoma, an entity with striking similarities to mesonephric carcinoma but currently favoured to be of Müllerian derivation based on its association with other Müllerian tumours and molecular findings, has also been recently described, and may histologically mimic both FATWOs and STK11 adnexal tumours. In this review, we provide a historical overview of upper female genital tract mesonephric proliferations and discuss mesonephric lesions, STK11 adnexal tumour, mesonephric-like adenocarcinoma, and mimickers, the most common being endometrioid carcinoma.

Incidental mesonephric remnant hyperplasia of the jejunal mesentery: A diagnostic challenge

Mesonephric remnants are embryonic vestiges of the mesonephric (Wolffian) ducts which regress during normal development. These remnants have been uncommonly reported in the female and male reproductive tract as a spectrum of morphologic lesions that can be misdiagnosed as carcinoma. One case of mesonephric remnant hyperplasia of the jejunal mesentery incidentally found in a 47-year-old man is herein reported. This is the first description of mesonephric hyperplasia arisen in the mesentery. The presence of ducts, tubules, and cysts lined by bland, epithelial, cuboidal cells with scant cytoplasm, and diffuse pseudoinfiltrative growth pattern can raise the possibility of neoplasia. Immunohistochemically, mesonephric epithelia have a characteristic staining. CD10 highlights the apical-luminal aspect of the cells. Besides, intense reactivity is showed for high-molecular-weight cytokeratin (CK), CK7, bcl2, and vimentin. The main differential diagnosis includes mesothelial hyperplasia, epithelial mesothelioma, well-differentiated neuroendocrine tumor, and infiltration due to acinar adenocarcinoma of the prostate. However, a detailed microscopic study with the aid of immunohistochemistry helps separate mesonephric remnants from malignant processes. The mesonephric hyperplasia of the mesentery we have reported adds to the spectrum of mesonephric remnants a new location. Familiarity with this lesion is indispensable to avoid overdiagnosis.

Uncommon Cervical Lesions: A Review and Discussion of the Differential Diagnosis

CONTEXT.—

While the vast majority of cervical tumors consist of human papillomavirus (HPV)-related squamous cell carcinoma or adenocarcinoma, a subset of rare tumor types, frequently unrelated to HPV, does occur in this location. These tumors vary widely in prognostic and therapeutic implications, and accurate recognition is crucial to providing appropriate treatment. Some are benign or portend a favorable prognosis (adenoid basal carcinoma, ectopic prostate tissue), while others are frankly malignant lesions with a less favorable prognosis (adenoid cystic carcinoma, HPV-negative endocervical adenocarcinoma, mesonephric adenocarcinoma, clear cell carcinoma, small cell carcinoma, and adenosquamous carcinoma).

OBJECTIVE.—

To review the morphologic features of uncommon cervical lesions, the utility of immunohistochemistry for distinction between these entities, and the clinical and prognostic implications of accurate diagnosis.

DATA SOURCES.—

University of Michigan cases and review of the pertinent literature regarding the entities described.

CONCLUSIONS.—

Key morphologic and immunohistochemical features detailed herein will allow for the accurate distinction between these uncommon cervical lesions. Morphology is most useful in discriminating between the entities, as there is frequent immunohistochemical overlap between them; however, in rare instances immunohistochemistry can be useful in resolving the diagnosis.

Ovarian Combined Low-grade Serous and Mesonephric-like Adenocarcinoma: Further Evidence for A Mullerian Origin of Mesonephric-like Adenocarcinoma

Mesonephric-like adenocarcinomas are rare neoplasms occurring in the uterine corpus and ovary which bear a close morphologic resemblance to cervical mesonephric adenocarcinomas. They also have a similar immunophenotype and harbor similar molecular abnormalities to mesonephric adenocarcinomas and it is debated whether they are truly of mesonephric origin or represent Mullerian neoplasms closely mimicking mesonephric adenocarcinomas. We report an unusual case with bilateral ovarian serous borderline tumors and extraovarian low-grade serous carcinoma (invasive implants). In one ovary, there was a component of mesonephric-like adenocarcinoma. The immunophenotypes of the serous and the mesonephric-like components were distinct and as expected for the individual tumor types (serous component diffusely positive with WT1 and estrogen receptor and negative with GATA3, TTF1 and CD10; mesonephric-like component WT1 and estrogen receptor negative and GATA3, TTF1, and CD10 positive; both components diffusely positive with PAX8 and exhibiting "wild-type" p53 immunoreactivity). In all components (bilateral serous borderline tumors, low-grade serous carcinoma and mesonephric-like adenocarcinoma), an identical KRAS mutation was detected (NM_004985.4): c.35G>A, p.(G12D) proving a clonal association between the serous and mesonephric-like components and excluding a collision neoplasm. This represents the second reported case of a combined ovarian low-grade serous tumor and mesonephric-like adenocarcinoma; in the previously reported case, an identical NRAS mutation was present in both components. These 2 cases provide evidence that ovarian mesonephric-like adenocarcinomas have, at least in some cases, a Mullerian origin and differentiate along mesonephric lines. We present additional evidence for this by reviewing associated findings in published and unpublished ovarian mesonephric-like adenocarcinomas; 8 of 11 of these neoplasms contained other Mullerian lesions in the same ovary, mainly endometriosis and adenomas/adenofibromas.

Female adnexal tumors of probable Wolffian origin: morphological, immunohistochemical, and molecular analysis of 15 cases

Female adnexal tumors of probable Wolffian origin are rare and present a diagnostic challenge due to their morphological and immunohistochemical overlap with more common ovarian and broad ligament entities. We evaluated the morphological, immunohistochemical, and molecular features of 15 tumors of probable Wolffian origin. Patients ranged from 32 to 69 (mean 47) years and tumors from 1.8 to 30 (mean 10) cm. All except one arose in para-adnexal soft tissues. Follow-up was available for six patients, five of whom were alive and well, while the sixth, who had extra-adnexal disease at diagnosis, died from unrelated causes. The following patterns were noted: tubular (all tumors), solid 11/15 (73%), sieve-like 7/15 (47%), and reticular 1/15 (7%). A myxoid background was present in 3/15 (20%) of tumors and eosinophilic luminal secretions in 11/15 (73%). Most tumors (12/15, 80%) had low-grade nuclear atypia, while three showed foci with scattered high-grade atypia. Mitotic index ranged from 0 to 17 (mean 4) per ten high-power fields. Tumors were positive for pankeratin and negative for TTF-1. EMA, GATA3, and PAX8 were positive in 2/10 (20%; focal), 3/15 (20%; focal), and 1/15 (7%; focal) of tumors, respectively. CD10, SF-1, calretinin, inhibin, ER, PR, cytokeratin 7, and WT1 were variably expressed. Pathogenic mutations were rare and included STK11 (n = 3), APC (n = 1), and MBD4 (n = 1). Copy number variations were detected in the three tumors with STK11 mutations and a myxoid background. These data demonstrate that female adnexal tumors of probable Wolffian origin are morphologically and immunohistochemically diverse, but infrequently harbor pathogenic mutations. However, their lack of mutations in contrast to their mimickers may be a valuable tool in diagnostically difficult cases.

A Comparison of GATA3, TTF1, CD10, and Calretinin in Identifying Mesonephric and Mesonephric-like Carcinomas of the Gynecologic Tract

Mesonephric carcinomas of the gynecologic tract are neoplasms that are often under-recognized due to their varied morphologic appearances. Recently, GATA3 and TTF1 have been reported to be useful immunohistochemical markers for distinguishing mesonephric carcinomas from its morphologic mimics. Herein, we compared the performance of GATA3 and TTF1 to the traditional markers used for mesonephric carcinomas, CD10 and calretinin. We studied 694 cases: 8 mesonephric carcinomas (7 cervical [includes 3 mesonephric carcinosarcomas], 1 vaginal), 5 mesonephric-like carcinomas (4 uterine corpus, 1 ovarian), 585 endometrial adenocarcinomas, and 96 cervical adenocarcinomas. Mesonephric-like carcinomas were defined as tumors exhibiting the classic morphologic features of mesonephric carcinoma, but occurring outside of the cervix and without convincing mesonephric remnants. GATA3 had the highest sensitivity and specificity (91% and 94%) compared with TTF1 (45% and 99%), CD10 (73% and 83%), and calretinin (36% and 89%). GATA3, however, also stained a substantial number of uterine carcinosarcomas (23/113, 20%). TTF1 was positive in 5/5 (100%) mesonephric-like carcinomas and only 1/8 (13%) mesonephric carcinomas. In 4/6 (67%) TTF1 positive cases, GATA3 exhibited an inverse staining pattern with TTF1. In summary, GATA3 was the best overall marker for mesonephric and mesonephric-like carcinomas, but cannot be used to distinguish mesonephric carcinosarcomas from Müllerian carcinosarcomas. The inverse staining pattern between GATA3 and TTF1, suggests that TTF1 may be useful when GATA3 is negative in small biopsies where mesonephric or mesonephric-like carcinoma is suspected. The greater TTF1 positivity in mesonephric-like carcinomas suggests they may be biologically different from prototypical mesonephric carcinomas.

Spinal Versus Intracranial Meningioma: Aberrant Expression of CD10 and Inhibin with Relation to Clinicopathological Features and Prognosis

CD10 and inhibin are used mainly in CNS pathology to distinguish hemangioblastoma from metastatic clear cell renal cell carcinoma. Some meningiomas can mimic both tumors and so we aimed at this study to investigate the expression of both markers in a large number of meningioma cases. One hundred thirty-four meningioma samples were collected, 14 of them were spinal and 120 were intracranial. Manual TMA blocks were constructed using modified mechanical pencil tip method and immunohistochemistry for CD10 and inhibin was done. Intracranial meningioma occurred in significantly younger age than spinal ones. Most of spinal meningiomas were of transitional histology. CD10 was expressed in 14% of cases with significant positivity in spinal rather than intracranial cases. Transitional meningiomas showed the highest positivity for CD10 expression, while the least positive was the meningiotheliomatous type. Inhibin was expressed in 6% of cases with no significant relation to clinicopathological and histological features. There was no significant relationship between the expression of CD10 and inhibin expression in meningiomas. In conclusion, spinal meningiomas differ than intracranial ones in many clinicopathological and biological aspects. Among these differences is CD10 expression being more expressed in spinal meningiomas. However CD10 and inhibin are aberrantly expressed in a proportion of meningiomas, both have no relations to poor prognostic factors but more caution should be exerted during usage of these markers in diagnosis of hemangioblastoma and metastatic RCC. Further studies are suggested for exploring more biological differences between spinal and intracranial meningiomas.

Cervical Mesonephric Adenocarcinoma With Novel FGFR2 Mutation

Mesonephric adenocarcinoma is a rare tumor, accounting for <1% of cervical cancers. Well-differentiated mesonephric adenocarcinoma can be difficult to distinguish from diffuse mesonephric hyperplasia. Herein, we report a case of well-differentiated mesonephric adenocarcinoma with an FGFR2 mutation not previously reported in the literature. Nonselective tyrosine kinase inhibitors or FGFR2 inhibitors may represent options for targeted therapy.

Diagnostic Algorithmic Proposal Based on Comprehensive Immunohistochemical Evaluation of 297 Invasive Endocervical Adenocarcinomas

The International Endocervical Adenocarcinoma Criteria and Classification was developed to separate endocervical adenocarcinomas (ECAs) into 2 main categories on the basis of morphology such as human papilloma virus-associated (HPVA) and non-human papilloma virus-associated adenocarcinomas. We aimed to improve the diagnostic accuracy of International Endocervical Adenocarcinoma Criteria and Classification by performing a comprehensive immunohistochemical evaluation and constructing objective immunohistochemical-based algorithms for the classification of these tumors. Tissue microarrays were constructed from 297 of 409 cases used to develop the original classification. Immunostains included p16, p53, estrogen receptor (ER), progesterone receptor, androgen receptor, Vimentin, CK7, CK20, HER2, HIK1083, MUC6, CA-IX, SATB2, HNF-1beta, napsin A, PAX8, CDX2, GATA3, p63, p40, and TTF-1. High-risk human papilloma virus (HR-HPV) was detected by in situ hybridization (ISH) using probes against E6 and E7 mRNA expressed in 18 different virus types. Vimentin, ER, and progesterone receptor were expressed in a significant minority of ECAs, mostly HPVAs, limiting their use in differential diagnosis of endometrioid carcinoma when unaccompanied by HPV-ISH or p16. HR-HPV ISH had superior sensitivity, specificity, and negative and positive predictive values compared with p16, as published previously. HNF-1beta did not have the anticipated discriminatory power for clear cell carcinoma, nor did MUC6 or CA-IX for gastric-type carcinoma. HNF-1beta and napsin A were variably expressed in clear cell carcinoma, with HNF-1beta demonstrating less specificity, as it was ubiquitously expressed in gastric-type carcinoma and in the majority of HPV-associated mucinous (predominantly intestinal-type and invasive ECA resembling stratified mucin-producing intraepithelial lesion [iSMILE]) and usual-type carcinomas. HIK1083 was expressed in nearly half of gastric-type carcinomas, but not in the vast majority of other subtypes. GATA3 was positive in 10% of usual-type adenocarcinomas and in single examples of other subtypes. Rare gastric-type and HPVA mucinous carcinomas displayed HER2 overexpression. Androgen receptor was positive in 6% of usual-type adenocarcinomas. Aberrant p53 expression was found in only 3.6% of usual-type HPVA carcinomas, but it was more prevalent in mucinous (intestinal type and iSMILE) HPVAs and non-human papilloma virus-associates (particularly in gastric-type carcinoma, >50% of cases). The following diagnostic classification algorithms were developed with the above data. Carcinomas without overt cytoplasmic mucin (endometrioid, usual-type endocervical, clear cell, and mesonephric carcinomas) can be subclassified using HR-HPV ISH, ER, and GATA3, whereas carcinomas with easily appreciated cytoplasmic mucin (endometrioid carcinoma with mucinous features, HPVA mucinous, and gastric-type carcinomas) can be subclassified with HR-HPV ISH and ER.

Mesonephric adenocarcinoma of the cervix: a case report with a three-year follow-up, lung metastases, and next-generation sequencing analysis

Background

Mesonephric adenocarcinoma (MNAC) is a rare tumor of the female genital tract, which originates from mesonephric duct remnants. Its diagnosis is pathologically challenging, because MNAC may exhibit a mixture of morphological patterns that complicates the differential diagnosis.

Case presentation

The patient in this case was a 48-year-old woman with a polypoid mass protruding into the endocervical canal. The patient underwent a total hysterectomy outside the institution. During biopsy, the mass showed a cerebroid aspect. Histological study revealed a tumor with a predominantly tubular and ductal growth pattern. The immunoprofile showed negative staining for calretinin, carcinoembryonic antigen (CEAm), estrogen receptors (ER), and progesterone receptors (PR), and positive staining for CD10, p16, and PAX2. The Ki-67 score was 46%. Using a next-generation sequencing assay, we documented genomic alterations in KRAS and CTNNB1, low tumor mutation burden (TMB), and an absence of microsatellite instability. In addition, gain of the long arm of chromosome 1 (1q) was also documented using chomogenic in situ hybridization (CISH). Three years later, the patient presented pulmonary nodules in the lingula and left basal lobe that were resected by thoracotomy. The histopathologic study of the pulmonary nodules confirmed the presence of metastases.

Conclusion

Carcinomas of mesonephric origin are among the rarest subtypes of cervical tumors. We report the first case of mesonephric adenocarcinoma of the cervix with lung metastases showing a CTNNB1 gene mutation.

Persistent Mullerian duct syndrome: Report of two cases with phenotypical immunohistochemical profiling

INTRODUCTION:

Persistent Mullerian duct syndrome is a rare disorder of male organ development characterized by internal male pseudohermaphroditism. Persistent Mullerian duct syndrome is usually an incidental finding in patients presenting cryptorchidism, inguinal hernia, or a previous story of undescended testes.

CASE DESCRIPTION:

We report on two cases of persistent Mullerian duct syndrome: an adult fertile male with uterus and ectopic prostate occurring as pelvic mass and a 75-year-old organ donor with uterus and two fallopian tubes, discovered in course of organ recruitment. We performed routine histological analysis and immunohistochemical profiling of the different tissue components. Examined tissues were all benign, and the living patient is well after surgery.

CONCLUSION:

In order to prevent further complications such as infertility and potential malignant change, surgeons and surgical pathologists must be aware of this condition and should consider excision of the Mullerian remnant where possible.

Mesonephric proliferations of the female genital tract

The mesonephric (Wolffian) duct regresses in females during embryological development. Remnants of this duct may persist typically along the lateral walls of the cervix, vagina, adnexa, and uterine corpus. These mesonephric epithelia may expand into hyperplastic proliferations and rarely form neoplasms. The spectrum of morphology, immunophenotype, clinical presentation, and molecular characteristics of mesonephric lesions is reviewed, with attention to distinction from entities in the differential diagnosis.

Biological Features of a Renal Cell Carcinoma Cell Line Derived from Spinal Metastasis

The establishment of a metastatic renal cell carcinoma (mRCC) cell line can facilitate the search for molecular mechanisms involved in RCC metastasis. A novel human mRCC cell line, designated RCC96, was established from an mRCC of the spine from a 65-year-old Chinese man. Morphology, cell cycle phase, chromosome number, cell capability of migration, tumorigenicity in nude mice, and cytogenetic features of RCC96 were investigated. Cell growth curve was detected and the cell number doubling time was 52 h. Karyotype analysis showed that these cells were polyploidy. Transmission electron microscope showed that cells were with large atypical nuclei, well-developed rough endoplasmic reticulum, rich Golgi complex, and mitochondria, as well as visible microacinar in the cytoplasm. PCR and immunofluorescence staining demonstrated that the expression of some genes such as KISS-1, MMP2, and VEGF in RCC96 was not entirely consistent with that in other RCC cell lines, indicating the differences between primary and metastatic RCC cell lines. The RCC96 cell line may serve as a useful tool for studying the molecular pathogenesis and testing new therapeutic reagents for mRCC.

Role of B Cell Development Marker CD10 in Cancer Progression and Prognosis

The human CD10 antigen is a single pass, type II transmembrane, 100 kD cell surface glycoprotein belonging to peptidase M13 family. Identified in common acute lymphoblastic leukemia as a cancer specific antigen, CD10 is a cell surface ectoenzyme widely expressed on different types of cells. Earlier, it was used only as a cell surface marker to identify and differentiate between haematological malignancies. Later, reported to be present in various malignancies, it is thought to play significant role in cancer development and progression. Regulated expression of CD10 is necessary for angiogenesis and so forth. However its expression level is found to be deregulated in different cancers. In some cancers, it acts as tumor suppressor and inhibits tumor progression whereas in others it has tumor promoting tendency. However, its role in tumorigenesis remains unclear. This review summarises structural features, functions, and probable role of CD10 in cancer development.

Differential Expression Patterns of GATA3 in Uterine Mesonephric and Nonmesonephric Lesions

GATA binding protein 3 (GATA3) is a recently described immunohistochemical marker that has proven useful in the characterization of breast and urothelial carcinomas. However, the expression pattern of GATA3 in mesonephric proliferations is largely unknown. The aim of this study was to examine the immunohistochemical expression of GATA3 in cervicovaginal mesonephric lesions and compare it to its expression in endocervical and endometrial adenocarcinomas and cervicovaginal endometriosis. A cohort of 107 cases, including 33 cases of mesonephric lesions and 74 cases of nonmesonephric lesions, was selected for the study. Of 33 mesonephric lesions, 31 (94%) cases (16 remnants, 12 hyperplasias, and 3 adenocarcinomas) were strongly and diffusely positive in tumor cell nuclei for GATA3. The remaining 2 mesonephric carcinosarcomas showed focal nuclear staining and rare nuclear positivity, respectively. Of 36 endocervical adenocarcinomas, 33 (92%) were negative for GATA3 and the remaining revealed focal weak nuclear staining. Of 34 endometrial adenocarcinomas, 32 (94%) were negative, whereas 2 showed rare nuclear positivity. All 4 cases of endometriosis were negative. The benign endocervical epithelium and the benign endometrium in most cases lacked GATA3 expression, whereas the benign squamous epithelium in the majority exhibited nuclear basal and parabasal staining pattern. Our study demonstrates that GATA3 protein is expressed in most mesonephric lesions, regardless of them being benign or malignant. In contrast, GATA3 is absent in the majority of endometrial and endocervical adenocarcinomas. These results support that GATA3 immunostain can be a useful tool in differentiating mesonephric lesions from endocervical and endometrial adenocarcinomas.

Clear-Cell Atypical Fibroxanthoma: A Combined Immunohistochemistry Analysis

Atypical fibroxanthoma is considered to be a low-grade sarcoma, characterized by a proliferation of bizarre spindled cells. A case of a rare variant of this tumor, a clear-cell atypical fibroxanthoma, presenting with rapid growth on a 63-year-old female, is reported. The differential diagnosis of a clear cell proliferation and a review of the immunohistochemistry markers used in the diagnosis of atypical fibroxanthoma are discussed. In particular, the usefulness of markers such as CD10, procollagen 1, CD68, CD163, CD99, and S100A6, and the importance of negative markers such as S100, cytokeratin, and desmin are emphasized. Furthermore, the development of a keratoacanthoma at the site of previous Mohs surgery is recounted.

[Tumor of the mesosalpinx with unclear differentiation]

Female adnexal tumors of probable Wolffian origin (FATWO) are rare tumors, which are mostly localized in the broad ligament or the mesosalpinx. They show high intratumor and intertumor variability of histological patterns (e.g. solid, tubular, cribriform and cystic) with usually unremarkable cellular and nuclear morphology and a lower mitotic rate. In general, they behave in a benign fashion but there are rare cases with malignant transformation, so that careful examination and surveillance are necessary. Differential diagnoses include Sertoli-Leydig cell tumors, metastasized endometrioid carcinoma and the FATWO-like variant of the endometrioid carcinoma of the fallopian tubes. The FATWOs express pancytokeratin, CD10, vimentin, calretinin and inhibin A. Estrogen and progesterone receptors are expressed in a minority of cases, whereas epithelial membrane antigen (EMA) is not detectable.

Hormone receptor-negative, thyroid transcription factor 1-positive uterine and ovarian adenocarcinomas: report of a series of mesonephric-like adenocarcinomas

AIMS

To report a series of uterine corpus (n = 7) and ovarian (n = 5) neoplasms which we believe probably represent mesonephric adenocarcinomas based on their characteristic morphology and immunophenotype.

METHODS AND RESULTS

All neoplasms exhibited a relatively constant and characteristic morphological appearance with an admixture of architectural patterns with small glands or tubules, some containing luminal eosinophilic colloid-like material, typically predominating. Solid and papillary architectures were also often present. The nuclear features were characteristic with atypical angulated clear vesicular nuclei which often exhibited overlapping. All the tumours were 'flat' negative with oestrogen receptor and progesterone receptor and all except one exhibited nuclear staining with thyroid transcription factor 1 (TTF1), which was often diffuse. All tumours exhibited wild-type staining with p53. CD10, calretinin and GATA binding protein 3 (GATA3) were positive in a variable proportion of the neoplasms.

CONCLUSIONS

We believe these neoplasms to represent mesonephric adenocarcinomas which have only rarely been reported to arise in the uterine corpus and never in the ovary. We recommend they be termed mesonephric-like adenocarcinomas until their histogenesis is firmly established.

Recent Developments in Non-HPV-related Adenocarcinomas of the Lower Female Genital Tract and Their Precursors

Most adenocarcinomas in the lower female genital tract (cervix, vagina, vulva) arise in the cervix and are associated with high-risk human papillomavirus (HPV) infection. However, there is an emerging spectrum of non-HPV-related cervical adenocarcinomas, the most common of which is so-called gastric type. In this review, the concept of gastric-type cervical adenocarcinomas and their possible precursor lesions is covered, the precursor lesions still being poorly understood. Other non-HPV-related cervical adenocarcinomas are also discussed, including new information regarding molecular events in mesonephric adenocarcinoma. A variety of primary vaginal adenocarcinomas, including clear cell, endometrioid, intestinal and gastric types are also discussed. The spectrum of benign and malignant glandular lesions involving the lower female genital tract and probably derived from misplaced Skene's (periurethral) glands is also covered.

Practical issues in uterine pathology from banal to bewildering: the remarkable spectrum of smooth muscle neoplasia

Among mesenchymal tumors of the uterus, smooth muscle neoplasms are most common. The wide morphologic spectrum, especially within the category of leiomyomas, is responsible for diagnostic problems more frequently with leiomyosarcoma (including mitotically active, apoplectic, and leiomyoma with bizarre nuclei) but also with endometrial stromal tumors. In the former scenario, clinical information, gross appearance as well as strict utilization of morphologic criteria including cytologic atypia, mitotic activity, and tumor cell necrosis are clues in establishing the correct diagnosis. It is important to keep in mind that mitotic rate thresholds vary for the different subtypes of leiomyosarcoma. Of note, p16 should be used with caution in supporting a diagnosis of leiomyosarcoma as it is often positive in leiomyomas with bizarre nuclei and leiomyomas with apoplectic change (in the latter most frequently and more intense near areas of necrosis). MED12 mutations have also a very limited role in this differential diagnosis. Endometrial stromal tumors are by far, less common than smooth muscle tumors, but can be confused with leiomyosarcomas if they are associated with an undifferentiated uterine sarcoma and the low-grade component is overlooked or they have a myxoid/fibroblastic morphology. The differential diagnosis may be confounded if the latter is associated with a high-grade endometrial stromal sarcoma. It is important to highlight that CD10 is not a reliable marker in these differentials and should be used as a part of a panel of antibodies that also includes desmin and h-caldesmon. Two other recently categorized tumors in the uterus that merit special mention are PEComa and inflammatory myofibroblastic tumor as they enter in the differential diagnosis of smooth muscle tumors. PEComa may be part of the tuberous sclerosis syndrome and may show either a predominantly epithelioid or spindle morphology or combination thereof. Rarely, it may contain melanin pigment. There is variable positivity for HMB-45, MelanA, MiTF, and CathepsinK, and some tumors have been shown to express TFE-3 especially when associated with "clear cell" morphology. Patients with adverse outcome have tumors with ≥2 of the following features: ≥5 cm, infiltration, high-grade cytologic features, mitotic rate ≥1/50 high-power fields, necrosis, or lymphovascular invasion. Inflammatory myofibroblastic tumor is important to recognize as it often mimics myxoid smooth muscle tumors, either benign or malignant. The presence of an associated lymphoplasmacytic infiltrate should alert to that possibility and ALK studies (immunostain or FISH) are helpful in establishing this diagnosis. These tumors can behave in a malignant manner if large, associated with abundant myxoid change, brisk mitotic rate or show tumor cell necrosis.

GATA3 Is a Sensitive and Specific Marker of Benign and Malignant Mesonephric Lesions in the Lower Female Genital Tract

GATA3 is a transcription factor critical for embryogenesis, development, and cell differentiation. Recent studies have suggested that GATA3 is a sensitive and relatively specific biomarker for urothelial and breast carcinomas, with most Müllerian carcinomas being negative. We investigated GATA3 expression in mesonephric/Wolffian remnants and tumors in the female genital tract. A western blot was performed to assess specificity for the GATA3 antibody. GATA3 immunohistochemistry was performed on 59 formalin-fixed paraffin-embedded mesonephric samples, including 17 mesonephric remnants (MR; 11 cervical and 6 fallopian tube), 15 mesonephric hyperplasias, 21 mesonephric carcinomas, and 6 female adnexal tumors of probable Wolffian origin. Thirty conventional endocervical adenocarcinomas (ENDO-CA), 9 gastric-type cervical adenocarcinomas, and 165 endometrial adenocarcinomas (EM-CA) were also evaluated. GATA3 nuclear intensity and extent of staining was evaluated. The western blot revealed GATA3 expression in seminal vesicle and cell lines derived from breast and urothelial carcinomas, but not in other cell lines including ovarian, cervical, and endometrial cancers. All cervical MRs and mesonephric hyperplasias, 5/6 (83%) fallopian tube MRs, and 20/21 (95%) mesonephric carcinomas were GATA3 positive, although with great variability in both intensity (weak to strong) and extent (1+ to 3+) of staining. Only 1/6 (17%) female adnexal tumors of probable Wolffian origin showed weak multifocal staining. One of 30 (3%) usual-type ENDO-CAs and 3/165 EM-CAs exhibited weak-moderate GATA3 immunoreactivity; all gastric-type cervical adenocarcinomas were negative. GATA3 is a highly sensitive and specific marker for mesonephric lesions in the lower genital tract; however, its utility in the upper genital tract may be more limited. In addition, GATA3 can aid in distinguishing lower genital mesonephric lesions from usual-type and gastric-type ENDO-CAs and uterine EM-CAs.

Targeted genomic profiling reveals recurrent KRAS mutations and gain of chromosome 1q in mesonephric carcinomas of the female genital tract

Mesonephric carcinoma is a rare form of gynecologic cancer derived from mesonephric remnants usually located in the lateral wall of the uterine cervix. An analogous tumor occurs in the adnexa, female adnexal tumor of probable Wolffian origin. The pathogenesis and molecular events in mesonephric carcinoma are not known. The aim of this study was to examine the molecular alterations in mesonephric carcinoma to identify driver mutations and therapeutically targetable mutations. This study consisted of 19 tumors from 17 patients: 18 mesonephric carcinomas (15 primary tumors and three metastatic tumors) and 1 female adnexal tumor of probable Wolffian origin. In two patients, both primary and metastatic tumors were available. Genomic DNA was isolated and targeted next-generation sequencing was performed to detect mutations, copy number variations, and structural variants by surveying full exonic regions of 300 cancer genes and 113 selected intronic regions across 35 genes. Fluorescence in situ hybridization (FISH) for 1p and 1q was performed in two cases. Eighty-one percent (13/16) of mesonephric carcinomas had either a KRAS (n=12) or NRAS (n=1) mutation. Mutations in chromatin remodeling genes (ARID1A, ARID1B, or SMARCA4) were present in 62% of mesonephric carcinomas. All mesonephric carcinomas lacked mutations in PIK3CA and PTEN. The most common copy number alteration was 1q gain, found in 12 (75%) mesonephric carcinomas; this was confirmed by FISH in two cases. Mesonephric carcinoma is characterized by molecular alterations that differ from those of more common variants of cervical and endometrial adenocarcinoma, which harbor KRAS/NRAS mutations in 7% and 25% of cases, respectively. KRAS/NRAS mutations are common in mesonephric carcinoma and are often accompanied by gain of 1q and mutations in chromatin remodeling genes. Targeting inhibitors of the RAS/MAPK pathway may be useful in the treatment of mesonephric carcinoma.

Differential patterns of PAX8, p16, and ER immunostains in mesonephric lesions and adenocarcinomas of the cervix

Mesonephric remnants, usually located deep in the lateral cervical wall, may become hyperplastic resulting in a florid proliferation. These can be misinterpreted as malignant and confused with endocervical adenocarcinomas. Recent data have shown that PAX2 is diffusely expressed in mesonephric remnants and hyperplasias. PAX8 is a related transcription protein that is expressed in tissues of müllerian and wolffian origin. In this study, we have investigated the utility of an immunohistochemical panel comprising of PAX8, estrogen receptor (ER), and p16 in the differential diagnosis between mesonephric proliferations and cervical adenocarcinomas. A database search was conducted for cases of mesonephric remnants/hyperplasia/carcinoma of cervix and invasive cervical adenocarcinomas. Immunohistochemical stains for PAX8, ER, and p16 were performed using the avidin-biotin peroxidase technique on the most representative tissue. The search yielded 28 cases of mesonephric proliferations of cervix (15 mesonephric remnants, 12 mesonephric hyperplasias, and 1 mesonephric adenocarcinoma) and 16 cases of cervical adenocarcinomas (15 usual type and 1 adenoma malignum). Immunohistochemically, all the mesonephric proliferations, regardless of being benign or malignant, displayed a consistent staining pattern-diffusely and strongly positive for PAX8, negative for ER, and patchy cytoplasmic staining for p16. The usual type cervical adenocarcinomas exhibited a variable staining pattern with PAX8 and ER but all were strongly and diffusely positive for p16. The case of adenoma malignum was PAX8 positive, ER negative, and showed weak and patchy staining with p16. Our study suggests that a panel of immunohistochemical stains composed of PAX8, p16, and ER is useful in the distinction between mesonephric proliferations and cervical adenocarcinomas.

The endometriotic tissue lining the internal surface of endometrioma: hormonal, genetic, epigenetic status, and gene expression profile

Ovarian endometriomas are found in a consistent proportion of patients with endometriosis and are associated with a more severe form of the disease. The endometriotic tissue lining the inside of the endometrioma has been extensively studied over the years mostly for the need to compare the molecular and cellular characteristics of eutopic and ectopic endometria. Several aspects of hormonal regulation, response to local inflammation, carcinogenesis, and modifications of the local environment have been investigated in order to characterize also the processes associated with peritoneal endometriosis. In this review, we have summarized the current knowledge of pathophysiology of endometrioma, with a particular focus on the cellular components lining the internal surface of the cyst in order to provide a comprehensive overview of the hormonal, genetic, epigenetic, and gene expression profiles of this essential part of the cyst.

The Utility of Immunohistochemistry in the Differential Diagnosis of Gynecologic Disorders

Context

Immunohistochemistry has assumed an increasing role in the identification and characterization of gynecologic disorders including lesions with deceptively bland morphology, uncommon and underdiagnosed neoplasms, and neoplasms with specific genetic alterations associated with overexpression or loss of expression of specific proteins. The diagnostic accuracy has been significantly improved owing to the discovery and increasing experience with the tumor-associated biomarkers, and the increasing demand for precise tumor classification to assess suitability for the expanding therapeutic modalities including clinical trials.

Objective

To differentiate lesions of the gynecologic tract through the use of effective immunohistochemical panels.

Data Sources

Literature review and authors' personal practice experience.

Conclusions

The application of diagnostic and prognostic immunohistochemical panels has enabled pathologists to better guide therapeutic decisions and to better predict the clinical outcome. It is now well established that the use of ancillary testing, including immunohistochemistry, has a significant power in the identification, differentiation, and classification of reactive, premalignant, and malignant gynecologic disorders. This article discusses the utilities and pitfalls of the commonly used immunohistochemical markers in the context of overlapping morphologic features encountered in the uterus, ovaries, and fallopian tubes.

Temporal changes in neutral endopeptidase/CD10 immunoexpression in the cyclic and early pregnant canine endometrium

CD10 is a multifunctional transmembrane neutral endopeptidase (NEP) that is considered to be a reliable marker of ectopic human endometrial stroma. Available information on NEP/CD10 protein expression in animal endometria is scarce. This study focused on the immunolocalization of NEP/CD10 in the canine uterus and on its temporal changes during the estrous cycle and early pregnancy (Days 11 to 23 post-LH surge) in healthy females. NEP/CD10 expression was found in the canine endometrial stroma in all stages of the estrous cycle, showing cyclic differences both in intensity and in distribution pattern. A small population of negative stromal cells in subsurface position was also observed. This population shared some morphological characteristics with the human predecidual cells, which became positive in progesterone-associated stages of the cycle. In addition, positive immunolabeling was also observed in canine myometrial stroma. In early pregnancy, the basal glandular epithelia and the syncytium cords remained negative to this marker contrasting with the trophoblast and the lacunar epithelium. A weak to moderate intensity of immunolabeling was observed in the decidual cells, whereas stromal immunolabeling was more intense at the delimitation of the syncytium cords. In conclusion, CD10 is consistently expressed in the canine endometrial stroma and myometrium but not in the endometrial epithelia. The characteristic pattern seen in early pregnancy also suggests a role for this molecule in the process of embryo invasion at implantation.

The spectrum of cervical glandular neoplasia and issues in differential diagnosis

CONTEXT

Premalignant and malignant glandular lesions of the cervix are known to often cause diagnostic problems with a variety of benign (more common) as well as other malignant mimics, the latter setting often being represented by secondary involvement by endometrioid endometrial carcinoma especially in small samplings.

OBJECTIVE

To highlight key histologic features and immunohistochemical markers that may be helpful in the distinction of in situ endocervical carcinoma from benign glandular proliferations, and those that separate different subtypes of invasive endocervical carcinoma, as well as invasive carcinoma from other carcinomas secondarily involving the cervix and nonneoplastic proliferations of the cervix.

CONCLUSIONS

Clinical and morphologic features as well as immunohistochemistry results should be used in conjunction in the differential diagnosis of glandular proliferations of the cervix, as correct interpretation has major clinical consequences for the patient in most instances (especially benign versus malignant). Immunohistochemical markers should be used as part of a panel of antibodies, as exceptions may occur to the usual pattern of staining, and if used singly, they may mislead the pathologist to establish a wrong diagnosis.

PAX2 and PAX8 Expression in Primary and Metastatic Renal Tumors: A Comprehensive Comparison

Context.—The diagnosis of renal cell carcinoma (RCC) remains problematic, especially in the context of metastasis or small-needle biopsies. PAX2 and PAX8 transcription factors are known to be expressed by several histologic types of renal neoplasms.

Objective.—To evaluate the diagnostic utility of PAX2 and PAX8 relative to one another, which has not been studied.

Design.—Consecutive tissue sections from the archival samples of 243 primary and 99 metastatic renal neoplasms were submitted to PAX2 and PAX8 immunostain.

Results.—Within the primary neoplasms, PAX2 versus PAX8 expression was noted in 90 of 95 (95%) versus 92 of 95 (97%) for clear cell RCC, 29 of 38 (76%) versus 38 of 38 (100%) for papillary RCC, 14 of 25 (56%) versus 22 of 25 (88%) for chromophobe RCC, 3 of 7 (43%) versus 5 of 7 (71%) for collecting duct RCC, 6 of 8 (75%) versus 8 of 8 (100%) for acquired cystic kidney disease–related RCC, and 7 of 13 (54%) versus 11 of 13 (85%) for oncocytoma. Regardless of histologic subtype, PAX8 staining was noted in more cells and with more intense staining than PAX2. Within the metastatic RCCs, PAX8 expression was more frequently positive than PAX2 expression (88 of 99 cases; 89%; versus 75 of 99 cases; 76%).

Conclusions.—Both PAX2 and PAX8 are diagnostically useful markers for both primary and metastatic renal neoplasms of a large variety of histologic types. However, PAX8 appears to be more sensitive than PAX2 in both primary and metastatic settings. PAX8 can be included in any immunohistochemical panel for the diagnosis of primary renal neoplasms. Adding PAX2 should be optional, but this would gain limited further diagnostic yield. In a metastatic setting, both PAX8 and PAX2 can be included in a panel because a small subset of metastatic RCCs are stained only with PAX2.

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.

An analysis of five clear cell papillary cystadenomas of mesosalpinx and broad ligament: four associated with von Hippel-Lindau disease and one aggressive sporadic type

AIMS

Clear cell papillary cystadenoma (CCPC) is associated with von Hippel-Lindau disease (VHLD), but rarely involves mesosalpinx and broad ligament (M/BL). This study provides new data about its behaviour and immunophenotype.

METHODS AND RESULTS

We performed an analysis of four benign cases of CCPC of M/BL with either characteristic clinical features or genetic markers [loss of heterozygosity (LOH)] of VHLD in patients ranging from 24 to 36 years and a sporadic case in a 52-year-old presenting with peritoneal metastases. All CCPCs were papillary but had solid and tubular areas. Haemorrhage, thrombosis and scarring were constant features and related to an unusual pattern of sub-epithelial vascularity. All clear or oxyphilic cells co-expressed cytokeratin 7 (CK7), CAM5.2 and vimentin, with strong apical CD10 and nuclear paired box gene 2 (PAX2) immunoreactivity. Three cases also showed positivity for VHL40, epithelial membrane antigen (EMA), Wilms' tumour suppressor gene (WT-1) and cancer antigen 125 (CA125) but only one expressed renal cell carcinoma (RCC) antigen. Vascular plexus overexpressed nuclear and cytoplasmic WT-1.

CONCLUSION

The VHLD-associated cases appeared to be benign, but the sporadic case exhibited a low malignant potential. CCPCs show histological and immunophenotypical similarities with the recently reported clear cell papillary RCC, although the previously unreported apical CD10 and nuclear PAX2 expression may be related to their mesonephric origin. CCPC has a distinctive sub-epithelial vascular pattern that is consistent with its pathogenesis.

Isolation of hofbauer cells from human term placentas with high yield and purity

PROBLEM  Placental villus macrophages (i.e., Hofbauer cells, HBCs) were identified more than 100 years ago. Alterations in their numbers and characteristics are associated with several complications of pregnancy. Although HBCs have previously been isolated and cultured, there is no consensus methodology to obtain these cells with high yield and purity for in vitro studies. METHOD OF STUDY  Hofbauer cells were isolated from human term placentas using protocols in which cytotrophoblasts (CTs) and fibroblasts (FIBs), other major villous cell types, were isolated in parallel. Enzymatic digestion, Percoll gradients, and immunoselection were used to isolate the three cell types. Purity was assessed by morphology, flow cytometry, and phagocytosis assays. RESULTS  Hofbauer cells were isolated with 98-99% purity and a yield of 130-200 × 10(6) cells/80-100 g of tissue. HBCs exhibited a pleiomorphic and vacuolated appearance for at least 5 days in culture medium with and without serum. High levels of phagocytosis in HBCs, but not in CTs or FIBs, confirmed macrophage function in HBCs. Phagocytotic activity was maintained across several days in culture. CONCLUSION  Hofbauer cells were isolated from term placenta with high yield and purity using protocols in which CTs and FIBs were also obtained. This methodology will foster future studies that examine the role of HBCs in regulating villus function.