Sclerotic Fibroma Presenting as an Axillary Mass: A Case Report with Imaging Features

Sclerotic fibroma or storiform collagenoma is a rare benign neoplasm that predominantly affects the skin layer of the head, neck, or limbs. Less frequently, it occurs in non-dermal spaces such as the subcutaneous layer. No cases have been reported in the axilla, and imaging findings of this rare entity have not been described in the literature so far. We present a case of sclerotic fibroma in the deep subcutaneous fat layer of the axilla and describe its ultrasound and computed tomography imaging features.