Immediate spermatogenesis assessment after testicular tissue retrieval for azoospermic males using touch print smear

Touch print smear (TPS) of testicular specimens provides immediate diagnostic results comparable to histopathology and in vitro fertilization laboratory findings. This study aimed to validate TPS as a rapid complement to histopathology for detecting post-meiotic germ cells in azoospermic patients.

We retrospectively analyzed 495 azoospermic patients (274 with obstructive azoospermia [OA]) who underwent testis needle biopsy (2015-2022). Specimens were immediately smeared onto sterile slides, then transferred into Bouin's solution for pathological diagnosis. Slides were stained with thionine and examined under light microscopy. Spermatogenesis development was compared between TPS findings and histopathology.

TPS and histopathology were concordant in 98.2% (269/274) of OA and 75.6% (167/221) of non-obstructive azoospermia (NOA) cases. Among discordant NOA patients, 74.1% (40/54) showed more advanced spermatogenesis with TPS. Of 20 patients in whom post-meiotic germ cells were identified by TPS but not by histopathology, 95% (19/20) achieved successful sperm retrieval during subsequent microdissection testicular sperm extraction (mTESE). Conversely, in NOA patients where TPS suggested less advanced spermatogenesis and failed to identify post-meiotic germ cells, the sperm retrieval rate was 57.1% (4/7).

TPS allows rapid identification of post-meiotic germ cells with excellent concordance in OA and provides clinically relevant information in NOA. Patients in whom TPS demonstrates post-meiotic germ cells have a high likelihood of sperm retrieval, whereas their absence on TPS indicates lower retrieval success, in which case histopathology remains a useful backup.