Massive lymphocytic infiltration of uterine leiomyomas associated with GnRH agonist treatment

Aims: To report two unusual cases of massive lymphocytic infiltration of uterine leiomyomas, following GnRH agonist treatment, Previous reports have described a variety of alterations in leiomyoma histology following such therapy, Methods and results: These cases were studied using haematoxylin and eosin stains, and immunohistochemistry for B and T-cell markers (CD20/CD79a and CD3/UCHL-1) was performed. Leiomyomas were heavily infiltrated predominantly by mature lymphocytes of T-cell phenotype, Associated myocyte degenerative changes were present, Conclusion: Massive lymphocytic infiltration of leiomyomas may occur as a result of GnRH agonist treatment, although the mechanism is unclear.