Macrogenitosomia Caused by Interstitial Cell Tumour of the Testis. A Case in a 71/₂‐Year‐Old Boy

Summary The case is the 13th that has been published. The symptoms (premature somatic and genital development) commenced when the patient was 7 years; 6 months later a tumour of the right testis, measuring 2times2x3 cm, was removed and verified microscopically as a typical interstitial cell tumour without signs of malignancy. Following the operation the patient's abnormally rapid development ceased. 10 months later the patient's condition was unchanged, but 18 months after the operation there was a slight regression of the symptoms. After the operation the remaining testis developed to more than twice its original size, which was considered a compensatory hypertrophy, as there was no palpable tumour and the excretion of 17‐ketosteroids, which before the operation was 40.1 mg in 24 hours, immediately fell to normal values and remained normal. The possibility of malignancy, the result of the hormone analyses and the regression of the symptoms after operation are discussed. The presence of malignant tumoura has been reported only in adults. In addition to the increased excretion of 17‐ketosteroids there was a slightly elevated excretion of oestrogenic hormone. The latter is supposed to have been caused by a production in the tumour cells of abnormal steroids with oestrogen effect, or by an excess of normal oestrogenic hormone. Eegression of the symptoms has not been observed in all the cases reported. The possibility of regression is greater the earlier the patient is operated on after the onset of the symptoms.