Evaluation of Retained Testes in Adolescent Girls and Women with Complete Androgen Insensitivity Syndrome

PURPOSE: To evaluate the magnetic resonance (MR) imaging appearance of the testes in women with complete androgen insensitivity syndrome (CAIS), including any benign or malignant changes. MATERIALS AND METHODS: This was a retrospective review of the testicular MR images and histologic reports from 25 patients with CAIS who chose to retain their testes beyond age 16 years and who were imaged between January 2004 and December 2010. Ethical approval was obtained, and informed consent was obtained from each subject to review the medical records, images, and histologic slides and reports. Imaging and histologic findings were compared. RESULTS: Twelve patients (mean age, 24 years; age range, 18-39 years) retained their testes and 13 (mean age, 22 years; age range, 17-37 years) eventually underwent gonadectomy. Review of the MR images showed that testicular parenchyma was heterogeneous in 30 of 46 testes (65%). The most common changes on MR images included simple-looking paratesticular cysts (34 of 46 testes, 74%) and low-signal-intensity, well-defined Sertoli cell adenomas (26 of 46 testes, 56%). Correlation of the histologic and MR imaging findings showed that MR imaging could correctly depict the presence or absence of Sertoli cell adenomas in 19 of 23 testes (83%). Paratesticular cysts were correctly detected in 22 of 23 testes (96%). Microscopic examination showed that the testes were composed of atrophic seminiferous tubules, whereas germ cells were found in 13 of 26 testes (50%). All paratesticular cysts were confirmed to be benign; however, a focus of intratubular germ cell neoplasia was found in a Sertoli cell adenoma. Premalignant foci were detected in three patients, two with intratubular germ cell neoplasia and one with sex cord tumor with annular tubules. No invasive cancers were found. CONCLUSION: MR imaging is accurate in the detection of testicular changes, including paratesticular cysts and Sertoli cell adenomas. Although these changes are usually benign, Sertoli adenomas can sometimes harbor premalignant lesions. MR imaging cannot depict premalignant changes; therefore, the standard of care for patients with CAIS should remain gonadectomy after puberty.