Mast cell numbers negatively correlate with fibrosis in cryptorchid testes

PurposeMast cells have been found to play a role in fibrotic processes in multiple organ systems and are increased in number in the testes of infertile men. We have reviewed the literature and to date have found no studies investigating the role of mast cells in fibrosis of undescended testis. We examined the expression of mast cells in human cryptorchid testes and compared mast cell expression with testicular fibrosis in these testes.MethodsTesticular biopsies from cryptorchid testis were collected over 2 years. Biopsies from 78 patients were retrospectively sectioned, stained, and reviewed for the amount of fibrosis (graded 0–3) as well as mast cell number (MCN). MCNs were quantified by tryptase staining, and the average MCN per high-powered field (HPF) was determined. Statistical analysis was performed using a one-way ANOVA with a Kruskal–Wallis test and post hoc analysis with the Dunn test when significant.ResultsLarger MCNs were significantly associated with lower fibrotic indices at the time of orchidopexy. The average MCNs were 2.06, 0.86, 0.37, and 0.58 for fibrotic indices of 0, 1, 2, and 3, respectively. MCNs were significantly higher in biopsies with a fibrotic index of 0 than all other groups (p < 0.05).ConclusionMast cell expression correlates inversely with testicular fibrosis in cryptorchid testes. Further studies correlating mast cell expression with testicular function in boys with cryptorchidism are warranted.