Primary carcinoid tumour of the testis
Article first published online: 28 JUN 2008
Volume 83, Issue 1, pages 153–154, January 1999
How to Cite
Glazier, D.B., Murphy, D.P., Barnard, N., Cummings, K.B. and Weiss, R.E. (1999), Primary carcinoid tumour of the testis. BJU International, 83: 153–154. doi: 10.1046/j.1464-410x.1999.00852.x
- Issue published online: 28 JUN 2008
- Article first published online: 28 JUN 2008
A 36-year-old white man presented with a 4-week history of a painless left testicular mass which was not associated with any urological or systemic symptoms. He denied a history of injury or discomfort. Upon examination the right testicle appeared normal but the left testis was indurated, but not tender. Testicular ultrasonography showed an isoechoic, slightly heterogeneous left intratesticular mass with no calcification, measuring 2.4×2.9×2.9 cm which was hyperaemic on colour flow Doppler imaging. A small hydrocele and varicocele were seen the left side. His βhCG and AFP levels were within normal limits; the patient underwent a left radical inguinal orchidectomy. The tumour was a firm tan-coloured mass, measuring 3.0×2.5×2.3 cm. Histology confirmed a pure carcinoid tumour (Fig. 1) with no teratomatous elements, invading into the testicular capsule. The epididymis and spermatic cord were free of tumour. Chromogranin positivity was detected on immunohistochemical staining (Fig. 2). CT of the abdomen and pelvis revealed no retroperitoneal lymphadenopathy. After diagnosing carcinoid tumour, 5-hydroxyindoleacetic acid (5HIAA) and serotonin levels were assessed but neither was elevated. The patient underwent an octreotide scan and small bowel follow-through which were negative. These negative investigations were felt to be sufficient to exclude a primary carcinoid tumour elsewhere. The patient opted to undergo a surveillance protocol and will be followed with serial CT of his abdomen, and assessment of 5HIAA and serotonin levels.
Carcinoid tumours have a reported incidence of 15 per million population per year in the USA and are rarely found outside the gastrointestinal or respiratory tract. Carcinoid tumours most commonly present in the fifth decade of life. The origin of carcinoid tumour of the testis is probably related to a one-sided development of teratoma and indeed, many tumours also have teratomatous elements . The most important first steps are to exclude metastatic extratesticular primary carcinoid tumours. There are significant implications for survival, as metastatic carcinoid tumours are usually part of widely disseminated disease with a poor survival rate. To date, only six primary testicular carcinoids have produced 5HIAA  and hence, once it has been established after orchidectomy that the tumour is carcinoid, detection of elevated urinary 5HIAA increases the possibility of a metastatic tumour. CT of the abdomen and pelvis should also be carried out. To metastasize, a gastrointestinal carcinoid is usually >2 cm in diameter and would be detected by CT, which can also exclude macroscopic lymphatic spread of a primary tumour. A chest X-ray will help rule out a bronchial carcinoid. Octreotide scintigraphy is a recent imaging modality for carcinoid tumours. The octreotide binds to type 2 somatostatin receptors, which are expressed by most carcinoid cells. This investigation can identify about two-thirds of primary and metastatic carcinoid tumours, but it is not necessary in every evaluation.
Carcinoid tumours are similar to phaeochromocytomas in that the malignant potential cannot be predicted by histological appearance. Testicular carcinoids rarely metastasize, with the overall incidence estimated at 11% . Tumours that metastasize tend to be larger (mean 6.5 cm) than those which do not (mean 2.9 cm) . Metachronous carcinoid tumours are very common. Hence, although retroperitoneal node dissection is not recommended, careful surveillance should be carried out.