MEN 2A-related cutaneous lichen amyloidosis: report of three kindred and systematic literature review of clinical, biochemical and molecular characteristics.

Multiple endocrine neoplasia type 2A (MEN2A) may be rarely associated with cutaneous lichen amyloidosis (CLA), a skin lesion located in the interescapular region. Here, we describe 3 MEN2A-related CLA kindred and perform a systematic review (SR) of the literature on clinical, biochemical and molecular characteristics of MEN2A-related CLA patients. Thirty-eight patients with MEN2A-related CLA followed at our institution were evaluated. The median age at MEN2A diagnosis in our cohort was 25 (13-41) years, 68 % were women and all harbored codon 634 RET mutations. The literature search resulted in 20 publications that contributed with 25 MEN2A families and 214 individuals. The mean age of MEN2A diagnosis was 31 ± 17 years, with 77 % women. The mean age reported by patients to initial skin lesion suggestive to CLA was 20 ± 13 years. All but two kindred harbored mutations at codon 634: C634R 7 kindred (35 %), C634Y 5 kindred (25 %), C634W 3 kindred (15 %), C634G 1 kindred (5 %), V804M 1 kindred (5 %) and S891A 1 kindred (5 %). Most interesting, the standardized CLA prevalence was higher in women (2.3/1.0, P < 0.005). The overall reported prevalence of medullary thyroid carcinoma, CLA, pheochromocytoma and hyperparathyroidism was 94, 51, 30 and 16 %, respectively. SR of literature indicates that MEN2A-related CLA is more frequent in women and presents a high penetrance, being the second most frequent manifestation of the syndrome, preceded only by MTC.