27933 A rare case of familial generalized multiple glomangiomas in an 11-year-old boy

Abstract

Glomus tumors are benign vascular neoplasms made up of specialized perivascular modified smooth muscle cells, glomus cells, that present clinically as violaceous-to-blue papules and nodules often on the distal fingers and toes, including the nail bed. Glomus tumors can be histologically classified into 3 variants: solid glomus tumors, glomangiomas, also known as glomuvenous malformations, and glomangiomyomas. We present the case of an 11-year-old boy who presented with multiple blueish lesions on the bilateral arms, trunk, and buttocks, present for 2-3 years. Of note, the patient’s brother reportedly has many similar lesions that developed around the same age. Physical exam revealed solitary and clustered tender, blue, nonblanching vascular papulonodules on the trunk, arms, and back. Biopsy of a lesion on the right arm was performed and histopathology revealed many dilated vascular channels surrounded by sheets of uniform round-to-cuboidal cells with oval nuclei, consistent with a diagnosis of glomangioma. Given the patient’s clinical presentation with multiple glomangiomas and a first degree relative with similar lesions, a diagnosis of familial generalized multiple glomangiomas (FGMG) was made. FGMG is a rare clinical variant present in less than 10% of all glomus tumor cases. FGMG is thought to be caused by mutations in Glomulin (GLMN) and exhibits autosomal dominant inheritance with incomplete penetrance and variable expressivity. Though glomus tumors are benign, they are typically persistent and may be tender. When desired, treatments with reported efficacy include sclerotherapy, local excision and electron beam radiation.