Extraskeletal Osteochondroma in an Unusual Location: A Case Report

Extraskeletal osteochondroma is a rare, benign, bone tumor of the soft tissue that generally affects the soft tissue of the hands and feet, followed by the trunk, and is rarely reported in the head and neck area. A 41-year-old female presented with an asymptomatic, skin-colored, palpable nodule on the neck that had been slowly growing over an unknown period of time. An ultrasound examination revealed a 0.9-cm-sized, dense, calcified lesion in the skin layer on the left side of the neck. Calcinosis cutis, pilomatricoma, and other benign tumors were clinically suspected, and a tumor excision was performed. The histological examination showed encapsulated round nodules composed of mature hyaline cartilage, which gradually changed into mature bone tissue. Extraskeletal osteochondroma was diagnosed by pathological examination. Here, we report an interesting case of extraskeletal osteochondroma in an unusual location. (Korean J Dermatol 2020;58(4):276∼278)