Intravasal "toothpaste" in men with obstructive azoospermia is derived from vasal epithelium, not sperm

Men undergoing vasectomy reversal many years after vasectomy are at increased risk for secondary epididymal obstruction. When this occurs the intravasal fluid is often a thick, white, toothpaste-like material devoid of sperm. In this study we characterize the vasal fluid found in men with a newly described entity, segmental dysplasia of the vas deferens, in which at least 2 distinct sites of vasal obstruction are present. We determine the significance of this fluid in men with obstructive azoospermia.

Three men who underwent scrotal exploration for obstructive azoospermia due to segmental dysplasia of the vas deferens were evaluated. Each underwent scrotal exploration including bilateral vasotomy and testicular biopsy. Intravasal fluid was collected, evaluated microscopically and sent for cytopathological evaluation.

All men had isolated segments of the vas 2 to 5 cm in length that were not connected to the epididymis or ejaculatory ducts. We have named this condition segmental dysplasia of the vas deferens. Vasotomy was performed between aplastic segments, revealing thick, white, toothpaste-like material identical to that seen in men with secondary epididymal obstruction undergoing vasectomy reversal. Cytopathological evaluation of this fluid revealed proteinaceous concretions and rare clusters of degenerated columnar epithelial cells, but no sperm or sperm products.

Thick, white, toothpaste-like material is produced between 2 obstructed segments as seen in men with segmental dysplasia of the vas deferens and with secondary epididymal obstruction. Our findings in men with segmental dysplasia of the vas deferens indicate that vasal "toothpaste" must be derived from vasal epithelium, not sperm.