Ultrastructural and steroidogenic characteristics of an androgen-producing adrenocortical tumour

A 16-year-old female patient with an adrenal tumour was studied. Clinically she had progressive hirsutism, showed high urinary 17-oxosteroid excretion with normal plasma cortisol. Plasma C19-steroids, both unconjugated (including testosterone) and sulphate-conjugated, were greatly elevated. On surgical exploration an adrenal tumour was histologically an adenoma. On ultrastructural analysis the cells in all zones of the adjoining adrenal were considered normal. Although the tumour cells had the general appearance of a steroid-secreting cell their structure diverged from the cells of every subzone of the cortex. This was the case particularly with mitochondria and lipid inclusions. The only endogenous unconjugated steroids detected in the adjoining cortex were corticosterone and cortisol while in tumour tissue these were present in lesser amounts. The tumour tissue contained large amounts of C19-steroids, 11beta-hydroxy-androstenedione being quantitatively most significant. On the basis of the steroid profile an impaired defect of 21-hydroxylation in tumour cells leading steroid synthesis from corticosteroidogenesis to the C19 pathway is proposed.