Testicular biopsy: clinical practice and interpretation.

Testicular biopsy was considered the cornerstone of male infertility diagnosis for many years in men with unexplained infertility and azoospermia. Recent guidelines for male infertility have limited the indications for a diagnostic testicular biopsy to the confirmation of obstructive azoospermia in men with normal size testes and normal reproductive hormones. Nowadays, testicular biopsies are mainly performed for sperm harvesting in men with non-obstructive azoospermia, to be used for intracytoplasmic sperm injection. Testicular biopsy is also performed in men with risk factors for testicular malignancy. In a subgroup of infertile men, there is an increased risk for carcinoma in situ of the testis, especially in men with a history of cryptorchidism and testicular malignancy and in men with testicular atrophy. Ultrasonographic abnormalities, such as testicular microlithiasis, inhomogeneous parenchyma and lesions of the testes, further increase the risk of carcinoma in situ (CIS) in these men. For an accurate histological classification, proper tissue handling, fixation, preparation of the specimen and evaluation are needed. A standardized approach to testicular biopsy is recommended. In addition, approaches to the detection of CIS of the testis testicular immunohistochemistry are mandatory. In this mini-review, we describe the current indications for testicular biopsies in the diagnosis and management of male infertility.