Nonobstructive azoospermia: a spectrum, not a single disease


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VOLUME 115, ISSUE 2, P315


Michael B. Tradewell, M.D., Thomas A. Masterson, M.D.


Reflections on "A predictive model to estimate the chances of successful sperm retrieval by testicular sperm aspiration in patients with non-obstructive azoospermia" by Majzoub et al.

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Fertility and Sterility

Editorial Office, American Society for Reproductive Medicine

Fertility and Sterility® is an international journal for obstetricians, gynecologists, reproductive endocrinologists, urologists, basic scientists and others who treat and investigate problems of infertility and human reproductive disorders. The journal publishes juried original scientific articles in clinical and laboratory research relevant to reproductive endocrinology, urology, andrology, physiology, immunology, genetics, contraception, and menopause. Fertility and Sterility® encourages and supports meaningful basic and clinical research, and facilitates and promotes excellence in professional education, in the field of reproductive medicine.


Go to the profile of Peter N Schlegel
about 2 months ago

In their Reflection, Tradewell & Masterson comment on the value of FSH and testis volume to predict the chance of sperm retrieval in men with non-obstructive azoospermia, in a series published in the same journal issue by Majzoub et al.  The authors of the Reflection appear to miss the concept that men with obstructive azoospermia can also be identified by the presence of normal FSH and normal testicular volume.  It has been long-ago identified that azoospermic men with a testis length >4.5 cm and FSH <7.6 have a 90% chance of obstructive azoospermia (Schoor et al., 2002).  Since 64% (45/70) of the men who underwent successful TESA had no histologic evaluation, but normal testis volume and normal FSH, the reviewers/Reflectioners seem to miss the obvious conclusion that most of the men with sperm retrieved by TESA likely had obstructive azoospermia rather than non-obstructive azoospermia.  Indeed, of the articles which demonstrate that low FSH and normal testis volume predict sperm retrieval in NOA, most of them have very limited testis sampling and/or include men with obstruction.  Mature series of effective microTESE procedures have demonstrated no adverse predictive value of elevated FSH on sperm retrieval rates (and, indeed, a trend toward lower sperm retrieval in those men with low FSH who are more likely to have diffuse maturation arrest; Ramasamy et al., 2009).

Interpretation of studies that propose preoperative predictive values in men with NOA who undergo attempted sperm retrieval must be carefully reviewed to assess for the extent of sperm search with microTESE as well as the potential contamination of the study population with men who have obstructive azoospermia.  Failure to do so results in pollution of our published literature with misleading information that can ultimately lead to harm to our patients who may be given inaccurate preoperative counseling.


Ramasamy R, Lin K, Gosden LV, Rosenwaks Z, Palermo GD, Schlegel PN.  High serum FSH levels in men with nonobstructive azoospermia does not affect success of microdissection testicular sperm extraction.  Fertil Steril. 2009 Aug;92(2):590-3.

Schoor RA, Elhanbly S, Niederberger CS, Ross LS. The role of testicular biopsy in the modern management of male infertility.  J Urol 2002 Jan;167(1):197-200.

Go to the profile of Thomas A. Masterson, M.D.
about 2 months ago

Thank you for the insightful reply! You are without a doubt the authority on mTESE! I agree with your points and they are well taken. It is certainly a possibility that some of the men included into the study may have had obstructive azoospermia, and this could affect the results which are similar to Schoor et al.  Although TESA success was similar to other published series of NOA, suggesting similar populations.

I continue to believe that NOA is the phenotype of diverse pathologies, and inconsistent identification of sperm supports this.  In two nearly identical men (similar labs, history and exams), why we find sperm in one and not the other, remains unanswered.

To address one of your points, the manuscript by Schoor et al. to predict OA vs NOA is very useful for patient counseling. However, we cannot forget that 10% of NOA will present with normal testis volume and normal FSH. Something not mentioned in most studies are epididymal exam findings. I have encountered several men with azoospermia, normal FSH and normal testis volume with flat epididymal exams who have negative TESA. Compare this to the post vasectomy patients who often have a full or dilated epididymis. What is your experience with these challenging 10% NOA men with normal FSH and normal testis volume? Do you find epididymal exam important?