Percutaneous biopsy of the testicle: a mini review with a proposal flow chart for non-obstructive azoospermia

A general consensus on the role of testicular biopsy in non-obstructive azoospermia (NOA) is needed. This paper reviews and updates technical aspects and clinical performance of the percutaneous testicular biopsy techniques, in particular large-needle aspiration biopsy (LNAB), and proposes a flow chart for the management of NOA. The English literature and original data were reviewed or analyzed. Large-needle biopsy (LNB) includes large-needle cutting biopsy (LNCB) and large-needle aspiration biopsy (LNAB). LNCB usually requires scrotal incision for the insertion of relatively large needles. Fine-needle aspiration biopsy (FNAB) does not require surgical equipment or expertise, employs the smallest needles (23- to 20-gauge), and permits sperm cytologic detection. LNAB also does not require surgical equipment or expertise, employs needles of size from 20- to 18-gauge, is safe, and can be used for testicular histology and sperm recovery. An operative flow chart is proposed for the management of NOA in which FNAB, LNAB and open surgical biopsy are used for the optimal management of NOA.