Malignant sex cord-stromal tumour in a patient with the androgen insensitivity syndrome

A malignant sex cord–stromal tumour that occurred in a 56‐year‐old patient with the androgen insensitivity syndrome is reported. Although hamartomas composed of sex cord cells are common in the testes of patients with this syndrome, unequivocal neoplasms of sex cord type are rare. The tumour described herein most closely resembled, but lacked the overall morphology of, a juvenile granulosa cell tumour, and Charcot‐Böttcher filaments, indicative of Sertoli cell differentiation, were seen on electron microscopy. The features of the androgen insensitivity syndrome and the various tumours that have been reported in patients with this syndrome are briefly reviewed.