Neuroendocrine Testicular Tumors: A Systematic Review and Meta-Analysis

The purpose of this study is to study the main epidemiological, clinical, para clinical, pathological, therapeutic, and evolutionary features of patients with testicular neuroendocrine tumors (TNET).

Nine case series and sixteen case reports were identified by searching PubMed database and qualified for inclusion in this study. We added the data of one case treated in the department of urology in Habib Bourguiba Hospital in Sfax, to the published cases.

A total of 132 cases were collected. Median age at diagnosis was 39 years old (range 10- 83 years). The most common presenting symptom was either a testicular mass or a swelling in 38.46% of cases. Carcinoid syndrome was documented in 10.60% of patients. The clinical examination revealed a palpable mass in 44.70% of patients. This mass was painless and firm in most cases. Serum tumor markers (β-gonadotrophine chorionique humaine, α-feto protein, and lactate dehydrogenase) were within normal limits in all patients except in one case. Most testicular neuroendocrine tumors (76.52%) were primary and pure. The tumors were positive for chromogranin (100%), synaptophysin (100%) and cytokeratin (93.10%). Metastases were detected at time of diagnosis in eight cases (6.06%). The main treatment was radical orchiectomy performed in 127 patients (96.21%). The 5-year overall survival rate was 78.70% and the 5-year specific survival rate was 84.30%.

The diagnosis of testicular carcinoids is based on the immunohistochemistry study. The treatment of choice for these tumors is radical orchiectomy. Somatostatin analogues were reported to be effective in patients with carcinoid syndrome.