Cutaneous mastocytoma simulating epidermal verrucous nevus in pediatrics: A case report

Abstract

Mastocytosis is a heterogeneous group of diseases characterized by clonal and abnormal proliferation of mast cells in the dermis. Its presentation is more frequent in the pediatric population. Cutaneous mastocytoma represents 10-30 % of cutaneous mastocytosis (CM) and can present polymorphism. We present the case of a 2-year-old male patient with a verrucous plaque on the left hand since birth, characterized by a negative Darier's sign. Dermoscopy showed whitish structures surrounded by reticular pigmentary networks, histopathology showed the presence of mast cells in the dermis, CD117 positive, showing findings compatible with mastocytoma. The treatment was topical corticotherapy with good progress. Knowledge of the dermoscopic features is helpful in establishing an accurate diagnosis of mastocytoma, but can be difficult when Darier's sign is negative and when the lesion may mimic other diagnoses. We report the following case because of its atypical presentation, the need for early diagnosis to prevent life-threatening episodes and to increase knowledge to support the diagnosis.