Endocrine Abstracts

Testicular neuroendocrine tumours (TNETs) are rare accounting for less than 1% of all testicular neoplasms. We present the case of a 64-year-old male referred from urology services with a slowly enlarging, painless, firm right testicular mass. This was on a background of chronic kidney disease IV secondary to membranoproliferative glomerulonephritis. Ultrasound revealed an enlarged right testis with a 2.5 x 2.8 x 3.3cm encapsulated, heterogenous, intratesticular mass. Of note, a previous testicular ultrasound in 2004 had shown a coarse calcification of the right testicle with a differential diagnosis at that time of old tuberculosis epididymitis. He proceeded to radical orchidectomy. Post-operative histology revealed a well-differentiated tumour, 27 mm in maximum dimension, Ki67 2%, with tumour cells positive for synaptophysin, cytokeratin AE1/3, somatostatin receptor 2A, and chromogranin. Findings were in keeping with a primary TNET, monodermal teratoma, pre-pubertal type. The patient is planned for Gallium DOTA-TOC PET CT to out rule metastatic disease with pending urinary 5HIAA. He denies any symptoms of carcinoid syndrome. TNET can be subdivided into pure tumours (75%) or tumours associated with teratoma (25%). Mean age at presentation is 46 years. Clinical carcinoid syndrome is seen in up to 12% of cases. Metastases via haematogenous spread can occur, with lymphatic spread also reported. Metastatic disease is usually associated with atypical features such as larger tumour size > 7 cm and carcinoid syndrome. Diagnosis is made histologically, and treatment is with orchidectomy. This case highlights the interesting association of a rare TNET associated with pre-pubertal teratoma.