Pure Sertoli cell tumour of the ovary: report of a case with ultrastructural observations.

A case of pure Sertoli cell tumour of the ovary is described. Unusual features were its great size, lack of clinical hormonal activity and the presence of granulomas in its interstitium. Mitochondria with tubular christae are described for the first time in such a tumour. These, together with lipid droplets and plentiful smooth endoplasmic reticulum, suggest a potential for steroid hormone synthesis which was not expressed clinically. Dense membrane-bound granules of undetermined type were present in large numbers. The presence of cilia and microvilli, and the absence of annulate lamellae and Charcot-Böttcher crystalloids, suggests that the tumour cells may not be truly of Sertoli type.