Abstract

Post-traumatic ‘pseudolipomas’ (PTL) are benign adipose masses which develop in the epidermis following an acute or chronic physical trauma to the soft tissue. Unlike traditional lipomas, post-traumatic adiposities are unencapsulated. Given their low rate of occurrence and the paucity of literature on these fatty tumors, the pathogenesis is not fully understood. This case illustrates a unique incidence of trauma-induced adipose proliferation.

A 27-year-old female presented to the family medicine clinic for a deformity of her right buttock. She first noticed a soft protruding mass months after landing on her buttocks onto a stick during physical training. Prior ultrasound proved unhelpful in determining the etiology. On physical exam she had a two-centimeter, flesh-colored protruding mass at the right buttock inter-gluteal fold which was soft, compressible and non-tender. There was no capsule, nodule, loculation or sinus tract. The patient underwent excisional biopsy with findings of benign appearing unencapsulated adipose tissue. The wound was closed and after several weeks she had a well-healing scar and no noted contour deficits of the buttocks. Months following the initial repair, the patient returned to the family medicine clinic with recurrence of the fatty protrusion and was referred to Plastic Surgery for definitive management.

Two of the leading pathogenic theories include (1) subepidermal fat herniation through the septa, and (2) inflammatory upregulation of preadipocytes which develop into mature adipocytes. Surgical excision or liposuction are the preferred treatments with unknown recurrence rates. The case highlights the importance of further exploration in post-trauma pathologies and their pathogenesis.