Diagnosis & Discussion
Diagnosis
Testicular adrenal rest tumor
Discussion
Testicular adrenal rest tumor (TART; also known as testicular tumor of the adrenogenital syndrome) is a benign mass-forming lesion commonly seen in patients with congenital adrenal hyperplasia. Patients usually present in childhood to early adulthood (average: 22.5 years) with bilateral (83% of cases) testicular masses. The diagnosis is confirmed by histologic examination of a biopsy or surgical specimen.
TART results from a hyperplastic reaction to excess ACTH by hormonally sensitive adrenal-like cells within the testis. A molecular signature similar to adrenocortical cells supports this view. In addition, cells of TART are positive for Leydig cell markers, thus also suggesting a pluripotent cell (adrenocortical and testicular) origin.
On gross examination, TART appears as a firm, lobulated and well-delineated, but unencapsulated mass within the testicular parenchyma. On histology, TART shows large polygonal cells with round nuclei and abundant eosinophilic cytoplasm. Cytoplasmic brown lipofuscin pigment, as seen in cells of the adrenal cortex and Leydig cells of the testis, may be present.
Leydig cell tumor and Leydig cell hyperplasia show nearly identical histomorphology with TART. However, Leydig cell tumor and Leydig cell hyperplasia are not associated with congenital adrenal hyperplasia, and both frequently show Reinke crystalloids, which are absent in TART. TART marks with inhibin, CD56, and synaptophysin but is negative for cytokeratins and the androgen receptor. In contradistinction to TART, Leydig cell tumor/hyperplasia are androgen receptor-positive and show no more than weak reactivity for CD56 and synaptophysin.
Unfortunately, TART is not preventable, and there are currently no treatment guidelines for its management. Irreversible testicular damage with loss of fertility can ensue from the compressive effect of the masses and the toxic paracrine effect of elaborated steroids. Fertility can be preserved by semen cryopreservation. Intensified exogenous high-dose glucocorticoid treatment may improve fertility in some patients. Testis sparing surgery is indicated to prevent further/irreversible decline in gonadal function.
References
1. Jin HY, Choi JH, Kim GH, Lee CS, Yoo HW. Testicular adrenal rest tumors in a patient with untreated congenital adrenal hyperplasia. Korean J Pediatr. 2011 Mar;54(3):137-40. doi: 10.3345/kjp.2011.54.3.137. Epub 2011 Mar 31. PMID: 21738545; PMCID: PMC3121001.
2. Engels M, Span PN, van Herwaarden AE, Sweep FCGJ, Stikkelbroeck NMML, Claahsen-van der Grinten HL. Testicular Adrenal Rest Tumors: Current Insights on Prevalence, Characteristics, Origin, and Treatment. Endocr Rev. 2019 Aug 1;40(4):973-987. doi: 10.1210/er.2018-00258. PMID: 30882882.
3.Smeets EE, Span PN, van Herwaarden AE, Wevers RA, Hermus AR, Sweep FC, Claahsen-van der Grinten HL. Molecular characterization of testicular adrenal rest tumors in congenital adrenal hyperplasia: lesions with both adrenocortical and Leydig cell features. J Clin Endocrinol Metab. 2015 Mar;100(3):E524-30. doi: 10.1210/jc.2014-2036. Epub 2014 Dec 8. PMID: 25485724.