Testicular Sex Cord Stromal Tumors (TSCST)

Patients with TSCSTs typically present with indolent intra-testicular mass. Apart from benign disorders such as varicocele, cysts etc., malignant germ cell tumors (GCT) and teratomas are the most relevant differential diagnosis.1 Beyond infancy, malignant GCTs are almost exclusively yolk sac tumors, characterized by serum secretion of alpha-fetoprotein (AFP). After the onset of puberty, other histological types such as seminoma, embryonal carcinoma and choriocarcinoma may develop, being clinically categorized into seminoma and non-seminoma.
Most of TSCSTs present as painless testicular swelling. The only specific clinical manifestation that distinguishes TSCSTs from other testicular tumors of different histological origin is its hormonal secretion. However hormonal activity is mostly observed in Leydig cell tumors, a very rare type of pediatric SCSTs in which testosterone secretion is responsible of isosexual precocious pseudopuberty in prepubertal boys or gynecomastia due to aromatization of testosterone to estradiol in Leydig cells or adipose tissue.5Large-cell calcifying Sertoli cell tumors are another histological subtype of TSCSTs encountered in prepubertal boys, teenagers and young adults, which could be revealed by endocrine signs, in particular gynecomastia due to aromatase activity in Sertoli tumor cells. The main other pediatric TSCST is juvenile granulosa cell tumor (GrCT), mostly diagnosed in the first year of life as painless testicular swelling. All these pediatric TSCSTs have a benign course after curative total orchiectomy. A genetic susceptibility syndrome is rare but has to be explored in cases of large-cell calcifying Sertoli cell tumors which are associated with Peutz-Jeghers syndrome (STK11 mutations) and Carney complex (PRKAR1A mutations).

Diagnostic work-up