Testicular adrenal rest tumors - Epidemiology, diagnosis and treatment

Introduction: Testicular adrenal rest tumors (TART) are common in males suffering from congenital adrenal hyperplasia (CAH). Correct and timely diagnosis is important for differential diagnosis with malignant testis tumors, related infertility and as TART may worsen in time, especially in the absence of adequate and continuous hormonal control. The rarity of the disease, predominance of small cohorts and case reports and research heterogeneity (concerning type of CAH, patients' age and specific focus of the paper) complicate the understanding of this condition.

Objectives: To review epidemiological and clinical aspects of TART, including treatment and prognosis.

Methods: Non-systematic review of CAH-related TART research.

Results: TART's prevalence grows progressively over time, predominating after puberty, affecting a mean of 20-40 % of CAH males. There is no proof of more frequent proportional affection of specific CAH phenotypes or types of enzyme deficiency, but cases of TART among non-classic CAH patients have been rarely reported. Chronic undertreated are more frequently affected and present larger tumors. Systematic ultrasound screening of CAH males is the state-of-the art for diagnosis, but TART are still often diagnosed in CAH adults seeking infertility treatment. TART are usually asymptomatic and present normal testicular volume. Biopsies are not recommended, except when the differential diagnosis between TART and testicular tumors cannot be guaranteed. Abnormal semen analysis is common. Leydig cell tumors are the main differential diagnosis, due to histological similarities to TART. Misdiagnosis may lead to unnecessary orchiectomies. Preservation of gonadal functions is inversely proportional to the total tumor volume. Tumors tend to regress under adequate adrenal suppression with steroids. Surgery in not indicated to treat TART.

Discussion: The reported prevalence of TART depends on age, usage of systematic follow-up ultrasound, and adequate CAH control. Timely detection of the disease is important to avoid irreversible gonadal dysfunction (not clinically apparent, due to high serum levels of androgen) and infertility. The relationship between TART and specific CAH phenotypes/genotypes has not been proved, and some cases do not present abnormal serum ACTH levels. Knowledge about TART should be disseminated among non-experts, to avoid unnecessary orchiectomies and false diagnosis of malignant testis tumors. Infertility is frequent, but has not been not satisfactorily addressed by physicians, even among experts. Sperm cryopreservation should be early offered to CAH adult males, but there are offer problems related to high cost.