Interstitial cell tumour of the testis in a western lowland gorilla (Gorilla gorilla gorilla)

The post mortem in an adult male gorilla (Gorilla gorilla gorilla) aged approximately 33 years revealed very small testes, and the cut surface of the left testis appeared nodular. Microscopic examination showed a marked atrophy of seminiferous tubules and fibrosis together with a diffuse interstitial cell hyperplasia. Two interstitial cell adenomas were identified in the left testis.