Paratesticular cystadenomas with ovarian stroma, metaplastic serous Müllerian epithelium, and male adnexal tumor of probable wolffian origin: A series of 5 hitherto poorly recognized testicular tumors

Low-grade endometrial stromal sarcoma-like tumors in male with JAZF1 gene fusions

Low-grade endometrial stromal sarcoma (ESS) is a hormone-responsive low-grade sarcoma typically occurring in the uterine corpus in women. Their genetic hallmarks are recurrent gene fusions involving JAZF1, partnering with either SUZ12 gene or less commonly with PHF1. Low-grade ESS-like sarcoma, or endometrioid stromal sarcoma, is exceptionally rare in males and has been reported to date only in two cases, one in the paratesticular area and the other of prostatic stromal origin. We report herein two new cases of low-grade ESS-like sarcoma in male patients, one presenting as a periprostatic/peri-rectal mass with a JAZF1-GLI3 fusion, while the other as a paratesticular mass with a JAZF1-PHF1 fusion. As the GLI3 fusion appeared novel, we searched the transcriptional signature of 35 low-grade ESS from our archives and found a similar JAZF1-GLI3 fusion in a low-grade ESS arising from the uterine corpus, supporting a common pathogenesis. Histopathologically, both cases demonstrate cellular, monotonous proliferation of ovoid to fusiform cells with a background of arteriolar vascular network. Immunohistochemically, the neoplastic cells express ER, PR, and CD10, similar to ESS. One case also expresses diffuse and strong AR. On follow-up, the patient with the periprostatic mass recurred 2 years after initial surgery with peritoneal "sarcomatosis." We describe the salient diagnostic morphologic, immunohistochemical, and molecular features and discuss the differential diagnosis and possible pathogenesis of this unusual entity.

KRAS Mutation in Serous Borderline Tumor of the Testis: Report of a Case and Review of the Literature

Ovarian-like epithelial tumors of the testis, including serous borderline tumors, are rare entities. We report the case of a 60-year-old man with a left intratesticular mass who had a radical orchidectomy. Histologically, the tumor was identical to the ovarian counterpart showing a well-delineated cystic lesion characterized by intraluminal papillae. The papillae are lined by atypical cuboidal or ciliated cells and are associated with psammoma bodies. The tumor cells express cytokeratin 7 (CK7), cytokeratin 5-6 (CK5-6), cancer antigen 125 (CA125), estrogen (ER), progesterone (PR), Wilm's tumor gene (WT1), paired box gene 8 (PAX8), Ber-EP4, and epithelial membrane antigen (EMA). The diagnosis of a serous borderline tumor of the testis was proposed. Mutation testing using next-generation sequencing showed a Q61K KRAS gene mutation. To the best of our knowledge, this is the second case report of a serous borderline tumor of the testis with a Q61K KRAS gene mutation.

Male adnexal tumor of probable Wolffian origin: a new entity in males similar to female adnexal tumor of probable Wolffian origin

Female adnexal tumor of probable Wolffian origin is a rare tumor listed in the 2016 WHO classification of the female reproductive tract. It does not have a WHO-recognized counterpart in the male urogenital tract. However, some cases of male adnexal tumors have been described in the literature. We present the case of a 41-year-old male who presented with a 2-cm nodule in the testicle. LDH, HCG, and AFP blood levels were normal. Gross examination showed an intratesticular, whitish, microcystic, firm, and encapsulated nodule of 2 cm. Microscopically, the tumor was well circumscribed, solid, and microcystic. In the solid areas, cells were fusiform or polygonal with an eosinophilic pale cytoplasm and a regular oval nucleus. Cysts were surrounded by a fibromuscular stroma and lined by a single layer of cylindrical epithelium, with apical cilia. On immunohistochemistry, tumor cells expressed AE1/AE3 and vimentin and were negative for calretinin, epithelial membrane antigen (EMA), and inhibin. All the differential diagnoses at this localization being ruled out, the tumor was compared to a female adnexal tumor of probable Wolffian origin. Both tumors had approximately the same morphological and immunohistochemical profile. Naming our tumor MATPWO is therefore justified, but it remains of a probable origin because further studies need to be performed in order to certify this hypothesis.

DICER1 screening in 15 paediatric paratesticular sarcomas unveils an unusual DICER1-associated sarcoma

Individuals with DICER1 syndrome, a genetic disorder caused by pathogenic germline variants in DICER1, are at increased risk of developing a wide array of predominantly childhood onset conditions, including genitourinary sarcomas. However, data on DICER1 involvement in paratesticular sarcomas have not been published. Herein, we analyse a series of 15 paediatric paratesticular sarcomas and describe in detail the case of a male infant with a paratesticular myxoid tumour, considered to be a low‐grade sarcoma, who also manifested a cystic nephroma, a classic DICER1 syndrome phenotype. He harboured a pathogenic germline DICER1 variant and different somatic hot‐spot mutations in each tumour. The paratesticular tumour showed strong and diffuse expression for WT1 and CD10, an unusual immunophenotype in paediatric sarcomas, but typical of tumours of Müllerian origin. The tumour was postulated to arise from the appendix testis, a Müllerian remnant located in the paratestis. Such an origin would be analogous to other DICER1‐associated non‐epithelial gynaecological tumours, thought to arise from Müllerian derivatives. These findings point towards a key role of DICER1 in Müllerian‐derived structures. Supporting this hypothesis is the fact that the other paratesticular sarcomas from the series were either negative or focally positive for WT1 and for CD10, and none had any DICER1 mutations. In summary, we present the first case of a paratesticular sarcoma associated with DICER1 syndrome, emphasising that paratesticular tumours with an unusual histological appearance may suggest an underlying DICER1 mutation, especially in the presence of a personal or family history of DICER1‐associated disease. In this context, DICER1 mutation testing could lead to changes in clinical care including implementation of cancer care surveillance strategies.

Wolffian tumor (female adnexal tumor of Wolffian origin) presenting as a pelvic side wall mass: Report of a case

The Wolffian tumor, previously identified as “female adnexal tumor of probable Wolffian origin,” is a rare tumor first described in 1973. The tumor is usually benign and is characterized by diffuse and tubular patterns, accentuated by reticulum and periodic acid–Schiff stains. Immunohistochemistry is used to further identify and classify these tumors, which are positive for cytokeratins, vimentin, inhibin, calretinin, and CD10 and negative for cytokeratin 20, epithelial membrane antigen, estrogen receptor, progesterone receptor, 34betaE12, and glutathione S-transferase. We report the case of a 47-year-old female with Wolffian tumor arising from the pelvic sidewall, separate from all reproductive organs. This is the first reported case of Wolffian tumor in this location.

Low-grade Endometrioid Stromal Sarcoma of the Paratestis: A Novel Report With Molecular Confirmation of JAZF1/SUZ12 Translocation

Tumors with Müllerian-like serous or mucinous phenotypes originating in the testis and its adnexa are rare neoplasms that have been increasingly recognized in recent years. Cystadenomas with or without ovarian-type stroma, borderline tumors, and adenocarcinomas are the main documented types. Although a handful cases of putative endometrioid adenocarcinomas have been reported, to our knowledge no case of endometrial stromal-type neoplasm has ever been reported in the literature. A 59-year-old man presented with a 2 cm left intrascrotal mass that was found on sonographic examination to arise from the epididymal tail with prominent vascularization. He was otherwise healthy without significant clinical history, endocrinopathy, or external hormone therapy. His testicular tumor markers (beta-HCG, AFP) were normal. Histologic examination of the resection showed a multinodular tumor closely associated with the epididymis and composed of monotonous rounded to ovoid cells with scanty cytoplasm and prominent spiral-like arterioles and capillaries. Mitotic activity was high. No other tumor component was seen. Immunohistochemistry revealed strong and diffuse expression of vimentin, CD10, estrogen receptor, and progesterone receptor. Molecular examination (performed on paraffin-embedded tumor tissue using a 517 gene fusion next-generation sequencing assay) showed a JAZF1/SUZ12 translocation, which was then confirmed by fluorescence in situ hybridization (FISH). These findings are consistent with a low-grade endometrioid stromal sarcoma originating in the paratestis. This report represents a novel addition to the growing spectrum of Müllerian-analog testicular adnexal neoplasms.

High Grade Serous Cystadenocarcinoma of Testis-Case Report of a Rare Ovarian Epithelial Type Tumour

Ovarian epithelial type tumour of testis are extremely rare tumours that resemble ovarian surface epithelial tumours. They usually present as testicular or paratesticular tumours and can be serous, mucinous, endometrioid or Brenner tumour. Serous and mucinous types account for the majority of tumours. The tumours are benign, borderline or malignant, commonly borderline. Here, we report a case of high grade serous cyst adenocarcinoma of testis which manifested as extensive metastasis in supraclavicular, mediastinal and abdominopelvic groups of lymph nodes, lung and adrenal gland without clinical evidence of an overt primary tumour. We report this case so as to make clinicians and pathologists aware of this rare entity and to stress on the fact that this rare entity should be kept in mind when evaluating cases of metastatic adenocarcinoma in male patients.

Sertoliform Cystadenoma of the Rete Testis: Report of a Case and Review of the Literature

Sertoliform cystadenoma is a rare benign tumor of the rete testis with 8 previously reported cases and an additional 14 cases reported in an abstract form. It usually presents with a unilateral scrotal mass, clinically and radiologically indistinguishable from malignant testicular tumors. We report a 39-year-old man who presented with a right testicular mass. The patient underwent radical inguinal orchiectomy. Grossly, no masses were appreciated. After histologic examination with subsequent immunohistochemical staining, a sertoliform cystadenoma of the rete testis was diagnosed.

Conservative Treatment of Serous Borderline Paratesticular Tumor in a Pediatric Patient

Serous borderline tumors are rare neoplasms. Herein we report our conservative approach, whose rationale is neoplasm low-malignant potential. Tumor was removed under general anesthesia, and frozen section ruled out a germinal malignancy or a stromal tumor such as rhabdomyosarcoma. Ultrasound evaluation was initially performed every 3 months during the first 2 years, every 6 months during the next 3 years, and annually thereafter. After 8 years, the patient has not experienced any relapse, either clinical or ultrasonographical. In our opinion, conservative approach, whose final decision relies on intraoperative frozen section, represents the best option and does not jeopardize long-term oncological outcome.

Ovarian-type epithelial tumours of the testis: immunohistochemical and molecular analysis of two serous borderline tumours of the testis

Tumours of ovarian-epithelial type of the testis, including serous borderline tumours, represent very rare entities. They are identical to the surface epithelial tumours of the ovary and have been reported in patients from 14 to 68 years of age. We describe two cases of a 46- and a 39-year old man with incidental findings of intratesticular masses of the left respectively right testis. Under the assumption of a malignant testicular tumour the patients were subjected to inguinal orchiectomy. Histologically, the tumours were identical to their ovarian counterparts: They showed a cystic configuration with a fibrous wall and irregular papillary structures lined by partially multistratified columnar cells and areas of hobnail cells. Furthermore, there was mild cytological atypia with a proliferative activity of below 5 % as proved by Ki67 staining; mitoses could not be detected. Immunohistochemically, the tumour cells displayed expression of pan-cytokeratin AE3, progesterone receptor, Wilms’ tumour protein (WT1), and PAX8 (Paired box gene 8). Estrogen receptor was expressed in one case. Octamer-binding transcription factor-4 (OCT4), calretinin, thrombomodulin, and D2-40 were not expressed. Mutation testing of BRAF revealed a BRAF V600E mutation in one case, while testing for KRAS mutations proved to be negative in both. The BRAF mutated tumour showed strong cytosolic and membranous positivity for B-Raf also on immunohistochemical analysis. Comparative genomic hybridization of one case could not reveal any chromosomal aberrations.

The Application of Immunohistochemical Biomarkers in Urologic Surgical Pathology

Context

Tumors of the genitourinary tract can be diagnostically challenging, particularly in core biopsies and cystoscopic biopsies with limited material. Immunohistochemistry is a valuable tool to use when morphology alone is insufficient for diagnosis.

Objectives

To review tumors and benign lesions of the kidney, urinary bladder, prostate gland, testis, and paratesticular structures with an emphasis on difficult differential diagnoses, as well as staining patterns in normal tissue. Recommended immunohistochemical stain panels are discussed that can assist in the diagnostic workup.

Data Sources

Review of current literature.

Conclusions

Immunohistochemistry is a valuable tool, assisting in the diagnosis of problematic tumors and benign lesions of the genitourinary tract.