Promising Immunotherapy in Metastatic Testicular Sex Cord Stromal Tumours After First-Line Chemotherapy.

Background: Testicular sex cord stromal tumours (TSCSTs) are rare, with few studies focusing on the metastatic TSCST prognosis. The value of treatments, including radical orchiectomy (RO) and retroperitoneal lymph node dissection (RPLND), in preventing metastasis is controversial. Additionally, metastatic TSCSTs are resistant to chemotherapy. We aimed to assess the effectiveness and safety of immunotherapy in metastatic TSCSTs after first-line chemotherapy. Methods: We retrospectively screened patients with testicular tumours undergoing testis surgery between January 2005 and January 2019. Patients with TSCSTs who had undergone testis-sparing surgery (TSS) or RO were identified. The malignant type was defined as metastasis confirmed by pathology. Treatment responses, progression-free survival (PFS), overall survival (OS) and safety were analysed. Results: Among the 494 testicular tumour patients who received TSS or RO, 11 (2.2%) patients with histologically proven TSCSTs were identified. At the last follow-up, 7 patients survived without tumours, and 4 patients developed metastasis and received first-line cisplatin-based chemotherapy, with 1 of them achieving an objective response. Their PFS times were 1.5, 2.2, 9.0, and 17.0 months, respectively. Two patients received immune checkpoint inhibitors (ICIs) after developing chemotherapy resistance and achieved a partial response up to the last follow-up; one of them experienced Grade 1 adverse events, and the other experienced Grade 2 adverse events during immunotherapy. The median OS time of the 4 patients with metastatic TSCSTs was 32 months. Conclusions: TSCSTs are rare, and most are benign with a good prognosis. ICIs represent a promising option for improving clinical outcomes in metastatic TSCSTs.

Primary signet ring stromal tumor of the testis: a study of 13 cases indicating their phenotypic and genotypic analogy to pancreatic solid pseudopapillary neoplasm.

Primary signet ring stromal tumor of the testis (PSRSTT) is an extremely rare tumor described only twice in the literature. Pancreatic-analogue solid pseudopapillary neoplasm (SPN) of the testis is a recently reported entity with morphological overlap with PSRSTT. We reviewed our files to find all cases of PSRSTT to better characterize this entity. We studied 13 cases of PSRSTTs using histological, immunohistochemical (IHC), and molecular genetic methods and compared the results with pancreatic SPN. Grossly, the size of PSRSTTs ranged from 0.5 to 2 cm (mean 1.1). Microscopically, PSRSTTs predominantly showed a proliferation of low-grade epithelioid cells containing characteristic cytoplasmic vacuole dislodging the nucleus (signet ring cells) separated by fibrous septa into trabeculae and nests. The immunoprofile was characterized by immunoreactivity for ß-catenin, cyclin D1 (nuclear positivity for both antibodies), CD10, vimentin, galectin-3, claudin 7, α-1-antitrypsin, CD56, and neuron-specific enolase and negativity for chromogranin, inhibin, calretinin, SF-1, NANOG, OCT3/4, and SALL4. In some cases, the IHC panel was restricted because of a limited amount of tissue. Molecular genetic analysis revealed mutations within exon 3 of the CTNNB1 encoding ß-catenin in all analyzable cases. Based on histological similarities between pancreatic SPN and PSRSTT and their identical IHC and molecular genetic features, we assume that both neoplasms share the same pathogenesis, and thus, PSRSTT can be considered as a testicular analogue of pancreatic SPN.

Uterine tumour resembling ovarian sex cord tumour is an immunohistochemically polyphenotypic neoplasm which exhibits coexpression of epithelial, myoid and sex cord markers.

AIMS: To describe the clinicopathological and immunohistochemical findings in four cases of uterine tumour resembling ovarian sex cord tumour (UTROSCT). METHODS: Four UTROSCTs were stained with a wide range of antibodies, including epithelial (AE1/3, epithelial membrane antigen), myoid (desmin, alpha smooth muscle actin, h-caldesmon), sex cord (alpha inhibin, calretinin, melan A, CD99) and neuroendocrine (chromogranin, CD56) markers as well as hormone receptors (oestrogen receptor, progesterone receptor, androgen receptor), vimentin, CD10, WT1 and HMB45. RESULTS: The tumours ranged from 0.8 to 19.5 cm. Three were relatively well circumscribed intramural myometrial lesions; the other was a pedunculated mass attached to the uterine serosa. The tumours were variably composed of solid, corded, trabecular, nested, glandular and retiform arrangements of tumour cells. In three cases, cells with eccentric nuclei and abundant eosinophilic cytoplasm, resulting in a rhabdoid appearance, were a prominent feature. Three cases were diffusely positive with AE1/3 and all with epithelial membrane antigen. Positivity with myoid markers was common with 3, 4 and 1 case respectively staining with desmin, alpha smooth muscle actin and h-caldesmon; 2, 4, 1 and 2 cases respectively were positive with alpha inhibin, calretinin, melan A and CD99. All were chromogranin negative and exhibited diffuse strong staining with CD56. All were diffusely positive with oestrogen receptor, progesterone receptor, vimentin and WT1. Three cases were androgen receptor positive and all were CD10 and HMB45 negative. CONCLUSIONS: UTROSCT exhibits a polyphenotypic immunophenotype with coexpression of markers of epithelial, myoid and sex cord lineage as well as hormone receptors.

Recent advances in immunohistochemistry in the diagnosis of ovarian neoplasms.

This leader reviews recent advances in immunohistochemistry that are useful in the diagnosis of ovarian neoplasms. These include the value of different anticytokeratin antibodies in the distinction between a primary ovarian adenocarcinoma and a metastatic adenocarcinoma, especially of colorectal origin. These antibodies have also helped to clarify the origin of the peritoneal disease in most cases of pseudomyxoma peritonei. The value of antibodies against so called tumour specific antigens, such as CA125 and HAM56, in determining the ovarian origin of an adenocarcinoma is also reviewed. In recent years, several studies have investigated the value of a variety of monoclonal antibodies in the diagnosis of ovarian sex cord stromal tumours and in the distinction between these neoplasms and their histological mimics. These antibodies include those directed against inhibin, CD99, Mullerian inhibiting substance, relaxin like factor, melan A, and calretinin. Of these, anti-alpha inhibin appears to be of most diagnostic value. It is stressed that these antibodies should always be used as part of a larger panel and not in isolation.

Value of A103 (melan-A) immunostaining in the differential diagnosis of ovarian sex cord stromal tumours.

AIMS: To assess A103 (melan-A) immunoreactivity in a range of ovarian sex cord stromal tumours and to evaluate it for the differential diagnosis of other neoplasms. METHODS: Paraffin embedded tissue sections from 45 sex cord stromal tumours and 44 potential histological mimics were examined immunohistochemically using the antibody A103. The sex cord stromal group included 21 adult granulosa cell tumours (AGCT), two juvenile granulosa cell tumours (JGCT), eight tumours showing Sertoli cell or Sertoli-Leydig cell differentiation, two unclassified tumours, two gonadoblastomas, one sex cord tumour with annular tubules, two steroid cell tumours, five thecomas/fibrothecomas, and two sclerosing stromal tumours. The histological mimics include 14 primary ovarian carcinomas, 13 metastatic carcinomas, four carcinoid tumours, four lymphomas, three endometrioid stromal sarcomas, two ovarian tumours of probable Wolffian origin, and one case each of small cell carcinoma, desmoplastic small round cell tumour, melanoma, and primitive neuroectodermal tumour. RESULTS: A103 immunoreactivity was identified in 25 sex cord stromal tumours including 10 AGCT, two JGCT, six Sertoli/Sertoli-Leydig cell tumours, two steroid cell tumours, three thecomas/fibrothecomas, and two sclerosing stromal tumours. Of the potential histological mimics, staining was present only in the two ovarian tumours of probable Wolffian origin and the melanoma. Immunoreactive stromal cells were noted in a minority of cases. Normal hilus cells and rete ovarii epithelium also expressed A103. CONCLUSIONS: A103 is a moderately sensitive and specific marker of sex cord stromal differentiation within the range of tumours examined in this study and as such is a valuable adjunct to other immunocytochemical markers in the assessment of diagnostically problematic ovarian tumours. The staining of normal and neoplastic Wolffian elements merits further investigation.

Testicular sex cord-stromal tumors in children: clinicopathologic study of sixteen children with review of the literature.

Sex cord-stromal tumors of the pediatric testis present diagnostic and therapeutic challenges. This study examines the clinicopathologic features of 16 testicular sex cord-stromal tumors from children less than 18 years of age. Four juvenile granulosa cell tumors and five tumors of Sertoli or incomplete differentiation in this study had high mitotic rates and/or sarcomatoid areas that suggested malignancy, but none of these children developed recurrence or metastases. Some of these tumors had been initially misdiagnosed as yolk sac tumors or rhabdomyosarcomas because of the presence of areas superficially resembling these neoplasms. These morphologic pitfalls have received little attention in the literature. Even incompletely differentiated sex cord-stromal tumors have at least focal areas characteristic of juvenile granulosa or Sertoli cell differentiation. In addition, immunohistochemical negativity for alpha-fetoprotein, muscle specific actin, and desmin are useful for ruling out yolk sac tumor and rhabdomyosarcoma. Four patients had Leydig cell tumors and three had large cell calcifying Sertoli cell tumors. Children with Leydig cell tumors are not at risk for metastasis, but children with large cell calcifying Sertoli cell tumors are at risk for endocrine syndromes as illustrated by one of our cases. The differential diagnosis of these tumors is also discussed.