Neuroendocrine Testicular Tumors: A Systematic Review and Meta-Analysis

Abstract

Purpose: 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). Materials and Methods: 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. Results: 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%. Conclusion: 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.

A Rare Case of a Testicular Teratoma Associated with a Neuroendocrine Tumour

“…The mixed teratoma and neuroendocrine type testicular tumours are rare (under 1%) and have been reported in only 22 cases in literature. The majority occurred in patients between 38.5-39 years (2,3). The diagnosis of this type of tumour is difficult and the IHC testing is crucial in establishing the precise diagnosis.…”

“…The specific markers for testicular tumours (beta chorionic human gonadotropin, alfa-fetoprotein and lactate dehydrogenase) are usually within normal limits. The association between immature teratoma and neuroendocrine tumour was described only in one case (2).…”

“…Neuroendocrine testicular tumors associated with teratomas are rare, 22 patients were diagnosed between 1930 and 2017 (2,4,5) which represented 16.67% of the total number of neuroendocrine tumors of testicular origin. Literature data showed that no patient with a mixed-type teratoma and neuroendocrine tumour developed visceral metastases, those being described only in the case of pure testicular tumors and localized at the level of the lungs (2). Our patient had a solitary right superior lobe metastasis as well as multiple metastases at the level of the spine.…”

“…Only 3 patients with pure neuroendocrine testicular tumours and concomitant metastases were given radiotherapy for the inter-aorto-caval and inguinal, lymph nodes, and the spine metastases, respectively (4). Some of the patients with pure testicular neuroendocrine tumours and visceral metastases were given Octreotide (2). Patient survival at 5 years was 84% and was considered better in associated tumours (teratoma and neuroendocrine tumour) compared to pure tumour forms (2,8,9).…”

“…Only 22 cases of testicular teratomas associated with a neuroendocrine testicular tumour were reported between 1930 and 2017 in the literature. This particular tumour form represents only 1% from the total of the testicular tumours (2).…”