Paraneoplastic Hyperthyroidism in Advanced Testicular Non-Seminomatous Germ Cell Tumors: Prevalence and Clinical Management.

INTRODUCTION: Paraneoplastic hyperthyroidism (PH) has been reported in patients with testicular germ cell tumors (GCTs), sporadically. This disorder is caused by extremely elevated serum levels of beta-human chorionic gonadotropin (bHCG). To date, little is known about the prevalence of PH, and its clinical features are poorly understood. The aim of the present study was to analyze the relative frequency and clinical features of PH in GCTs and evaluate their effects on therapeutic outcomes. METHODS: A cohort of 438 patients treated for testicular GCT from 2017 to 2023 was retrospectively analyzed for histology, age, clinical stage, and presence of PH. The clinical features of the patients with PH were evaluated descriptively. The relative frequency of PH was compared among the subgroups using descriptive statistical methods. RESULTS: Three patients with PH were identified; all had clinical symptoms of hyperthyroidism, suppressed serum levels of thyroid-stimulating hormone (TSH), and increased levels of tri-iodothyronin (fT3). All the patients had advanced, metastasized, and non-seminomatous GCTs. Serum bHCG levels ranged from 225,00 U/L to 1,520,000 U/L. The prevalence of PH was 0.7% in the entire GCT population and 60% in those with very high bHCG serum levels. All the patients received standard cisplatin-based chemotherapy along with thyrostatic treatment. The clinical symptoms of the hyperthyroidism rapidly disappeared. TSH levels normalized with decreasing bHCG levels. The PH treatment did not affect the therapeutic outcomes of the patients. CONCLUSION: PH may occur in 0.7% of all patients with GCT but may be present in up to 60% of patients with very high levels of bHCG. Measuring serum levels of TSH and fT3 should be performed in addition to routine diagnostic measures in all patients with poor prognosis GCTs. Thyrostatic medication is recommended for patients with the clinical symptoms of hyperthyroidism. Early recognition of hyperthyroidism and prompt intervention will reduce comorbidity and help optimize therapeutic outcomes.

Myoid gonadal stromal tumor of the testis-the novel subtype of testicular gonadal stromal tumors: a case report and review of the literature.

BACKGROUND: Sex cord gonadal stromal tumors compose less than 10% of all testicular neoplasms and consist of a variety of histological subtypes. In 2016, the World Health Organization introduced a novel subtype, the myoid gonadal stromal tumor, that consists of spindle-shaped cells with immunohistologic features of muscle cells. Only few cases have been reported to date. Due to its rarity and owing to its only recent introduction, the current knowledge about myoid gonadal stromal tumor is limited, and particularly, appropriate clinical management is still ill-defined. CASE PRESENTATION: A 47-year-old man of Caucasian descent presented with nonspecific scrotal discomfort. A roundish and well demarcated hypoechoic mass of 8.5 mm in diameter was detected in the cranial region of the left testis. Serum tumor marker levels were within normal ranges. Testis-sparing surgery revealed a 9-mm whitish, hard mass with sharp surgical margin. Histologically, the neoplasm consisted of microfibrillar tissue with spindle-shaped cells harboring elongated nuclei. Immunohistochemical work-up disclosed expression of desmin, small muscle actin, and S100 protein giving evidence for the myogenic nature of the neoplastic cells. There was no indication of malignancy, neither histologically nor clinically. Follow-up of 1 year was uneventful. CONCLUSION: A literature survey revealed 22 previous cases of myoid gonadal stromal tumor. The median age was 37 years, the median size of the neoplasm was 20 mm, and there was no side-preponderance. Myoid gonadal stromal tumor is not much different from other subtypes of gonadal stromal tumors nor from testicular gem cell tumors regarding age and laterality; however, tumor size is smaller in myoid gonadal stromal tumors than in germ cell tumors. Although rarely performed so far, testis-sparing surgery probably constitutes an appropriate treatment of this neoplasm. Myoid gonadal stromal tumor represents an emerging novel entity of benign testicular new growths that caregivers of patients with testicular tumors should be aware of.

Serum Levels of MicroRNA-371a-3p for Predicting the Histology of Postchemotherapy Residual Masses of Germ Cell Tumours.

BACKGROUND AND OBJECTIVE: Serum levels of microRNA-371a-3p (M371) represent a novel and sensitive biomarker of germ cell tumours (GCTs). This study analysed the utility of M371 to identify viable cancer (VC) in postchemotherapy (pc) residual masses with the underlying goal of avoiding overtreatment. METHODS: A multicentric, prospective diagnostic study was conducted in 180 GCT patients undergoing pc resection of residual masses. A correlation of M371 measurement results with the histological presence of VC in masses was found. A receiver operating characteristic analysis was performed for exploring the performance characteristics of the test. KEY FINDINGS AND LIMITATIONS: The sensitivity was found to be 68.9%, specificity 99.3%, area under the curve 0.813, positive predictive value 0.969, and negative predictive value 0.905; sensitivity is significantly associated with the percentage of VC in the mass. In specimens with ≤10% VC, there were 33.3% elevated M371 levels as opposed to 85.7% in specimens with >50% VC. Teratoma and somatic-type malignancy do not express M371. A lack of a central pathological review is a limitation. CONCLUSIONS AND CLINICAL IMPLICATIONS: The M371 test can identify 68.9% of patients with VC in pc masses. However, cases with <10% VC in the mass may escape detection. Teratoma does not express M371. The test alone cannot correctly identify patients requiring pc surgery, but it may be a tool for scheduling the extent of surgery. PATIENT SUMMARY: The microRNA-371a-3p (M371) test can identify about two-thirds of patients with viable cancer in residual metastatic masses following chemotherapy for germ cell tumours. Only masses with high percentages of viable cancer cells can be identified, and the histological subtype teratoma remains undetected with the test.