Acral lesions in tuberous sclerosis complex: Insights into pathogenesis

Background: Patients with tuberous sclerosis complex (TSC) are predisposed to developing ungual fibromas and other acral lesions. Objective: We sought to determine the numbers, types, and locations of acral skin lesions in TSC. Methods: We examined and photographed 76 adult women with TSC. Results: The age of the patients ranged from 20 to 69 years, with a mean age of 39 ± 11 years. Ungual fibromas were observed in 61 of 76 patients (80%). Periungual fibromas were more common than subungual fibromas, were more common on the feet than the hands, and showed the greatest frequency on the fifth toe. Longitudinal grooves in the nails occurred with or without a visible fibroma. Longitudinal short red streaks-lesions that we term "red comets"-were observed in 22 patients (29%). Longitudinal leukonychia was observed in 14 patients (18%). One patient had isolated digital overgrowth and one patient had pachydermodactyly. Limitations: No men or children were included in this study. Conclusions: Examination of patients for skin lesions of TSC could be improved by including inspection for longitudinal nail grooves, red comets, longitudinal leukonychia, and splinter hemorrhages in addition to ungual fibromas. The anatomic distribution of TSC ungual fibromas is not random and appears consistent with trauma-promoted tumor formation.