Klinefelter syndrome (KS) is the most frequent type of congenital sex-
chromosomal disorder caused by at least one extra X chromosome and commonly treated with lifetime
testosterone therapy. Ulcerative lesions on lower extremities may occur as a complication of KS. The pathogenesis of
ulcers in KS patients has not been clarified on a molecular level. Here we present a case of
leg ulcers exacerbation associated with the administration of a high dose of
acetylsalicylic acid in a 63-year-old KS patient with karyotype 47,XXY undergoing
testosterone replacement
therapy for the last 20 years. The appearance of the
ulcer on the patient's leg occurred during one week of high oral
acetylsalicylic acid intake (1.2 g daily). The patient was advised to return to his standard daily dose of 0.1 g of
acetylsalicylic acid and significant improvement of his
leg ulcer was observed after two weeks. We hypothesize that
testosterone-mediated
nitric oxide balance in KS patient is perturbed under the condition of acute high-dose
acetylsalicylic acid administration. We propose that small standard doses of approximately 0.1 g/day of
acetylsalicylic acid have no apparent effect on
nitric oxide status, whereas higher doses may cause dysregulation of
nitric oxide production and/or utilization, creating conditions which may cause the appearance of
leg ulcers in the KS patients.