FNAC in Evaluation of Azoospermic Males
FNAC has been used as a diagnostic modality for evaluation of male infertility. It is particularly helpful in differentiating obstructive azoospermia from spermatocytic arrest which is important since the treatment is entirely different.
In our analysis of 60 cases of azoospermic males subjected of FNAC, we concluded that FNAC is a simple, non-traumatic alternative to histology in assessment of male infertility.
Absence of sperms in the ejaculate doesn’t allow conclusions as to the functional status of the seminiferous epithelium. Hence, further evaluation of testicular function in azoospermic individuals is a must because only examination of testicular architecture and cell population can discriminate between an endogenous or exogenous etiology of disturbed fertility. The difference is of paramount importance since the treatment is entirely different (hormonal vs surgical correction).
Fine needle aspiration cytology (FNAC) of the testis pioneered by Obrant and Person (1965) and Person et. al.,(1971) has long been used as a diagnostic modality for evaluation of male infertility not only for documentation but also for quantification of spermatogenesis in azoospermic individuals. Various studies have shown FNAC to be a very reliable and reproducible method for evaluating spermatogenic activity with excellent correlation between cytologic and histologic diagnosis.
For FNAC, the scrotal skin is thoroughly cleaned with spirit with the patient in a recumbent position. An inguinal block is given with 2-2.5 ml of Lignocaine hydrochloride injected around the spermatic cord. After waiting for around five minutes, aspiration is performed with the help of a 23 G hypodermic needle. The testis is gently held between the thumb and the index finger, a single pass with a to-and-fro motion of the needle once or twice is made under suction. The material obtained is spread into the clean glass slides taking care to properly spread out the threads when obtained. The smears are air-dried and stained with May-Grunwald Giemsa.
A single smear is prepared from each testicle and examined under the light microscope. The different cell types are classified using the identification criteria described by Schenk and Schill.
Spermatogenesis is a hormonally regulated process where germ cells differentiate into mature spermatozoa by passing through several stages of meiosis. These intervening stages are of spermatogonia type A and B, primary spermatocytes which undergo meiosis to form two secondary spermatocytes, secondary spermatocytes undergo second meiotic division to form two spermatids, and spermatids finally transform into spermatozoa.
Depending upon the state of spermatogenesis in a particular patient, a variety of cell types-including Sertoli cells, spermatogonia, primary spermatocytes, secondary spermatocytes, spermatocytes (early and late) and spermatozoa are encountered in the smears. Based on various proportions of the different cell types, the smears are categorized into six groups.
1. Normal spermatogenesis – This pattern is described when the smears show spermatogonia, primary spermatogonia, spermatids, many spermatozoa and a proportional number of Sertoli cells forming roughly one third of the total spermatogenetic cells.
2. Hypospermatogenesis – This pattern is described when all cell types up to spermatozoa are present in the smears but the proportion of Sertoli cells to germ cells is increased.
3. Sertoli cell only – In this category, the smears reveal only Sertoli cells and a total absence of germ cells whatsoever.
4. Maturation arrest – Either early or late when there is an arrest at the stage of spermatogonia (spermatogonial arrest) or at the stage of spermatids (spermatidic arrest) with absence of spermatozoa.
5. Deficient spermatogenesis-maturation up to spermatozoal level is seen but number is too few.
6. Non-committal group.