Loss of fragile histidine triad (FHIT) expression and microsatellite instability in periocular sebaceous gland carcinoma in patients with Muir-Torre syndrome.

Abstract

To report fragile histidine triad expression and microsatellite instability in periocular sebaceous gland carcinoma. Interventional case series. Biopsy specimens of periocular sebaceous gland carcinoma obtained from six patients (mean age, 60 +/- 17 years; range, 38 to 83 years, 5 male, 1 female) with Muir-Torre syndrome and histopathologically proven sebaceous gland carcinoma were studied immunohistochemically for the presence of fragile histidine triad protein. Polymerase chain reaction-based analysis of the markers BAT25, BAT26, D2S123, D5S346, and D17S250 was performed for microsatellite instability in tumorous and matching normal tissues. Fragile histidine triad protein was detectable in the sebaceous gland carcinoma from one patient with microsatellite instability. It was not detectable in sebaceous gland carcinoma specimens from five patients without any evidence of microsatellite instability. Inactivation of fragile histidine triad tumor suppressor gene or inactivation of the mismatch-repair system resulting in microsatellite instability may contribute to the development of periocular sebaceous gland carcinoma in Muir-Torre syndrome.