A comparison of clinical characteristics of keratoacanthomas in Muir-Torre syndrome and xeroderma pigmentosum.

Abstract

Data on the clinical characteristics of keratoacanthomas (KAs) associated with Muir-Torre syndrome (MTS) and xeroderma pigmentosum (XP) are limited. To compare the clinical features of KAs in patients with MTS and XP. Consecutive patients diagnosed with MTS or XP were evaluated for the occurrence of KA in a single dermatology centre. Age at onset, number, size, localization, association with cutaneous horn, and regression patterns of KAs were compared in both groups and with sporadic KAs. A total of 26 KAs were observed in 7 of 38 patients with XP and 11 lesions in 4 of 8 patients with MTS with a mean age at onset of 11.4±6.5 and 50.5±8.5 years, respectively. Most individuals with both syndromes presented with multiple KAs. In MTS patients, lesions involved both facial and truncal sites and were frequently >1 cm in diameter, and spontaneous regression commonly resulted in depressed or hypopigmented, atrophic scars surrounded by a thin rim, and mutilation was observed in one case. In contrast, KAs in XP patients were predominantly localized to the head and neck, with occasional mucosal involvement, and were sometimes associated with cutaneous horn and typically healed with minimal or no scarring. Sporadic KAs manifested mostly as solitary lesions, predominantly on the face, in 14 patients with a mean age of 60.2±14.2 years. KAs in XP and MTS patients differ with regards to age at onset, distribution, associated features, and regression patterns. Truncal involvement, larger size and prominent scarring favour MTS, whereas early onset, mucosal involvement, and association with cutaneous horn are more characteristic of XP.