Comedones and Epidermal Cysts on the Abdominal Skin of a Dog Occurring After a Laparotomy

An 8-year-old neutered male shih tzu developed multiple cystic nodules on the abdominal skin following a laparotomy for cystolithectomy. These nodules, diagnosed as comedones and epidermal cysts, appeared 10 days post-surgery along the suture line and surrounding skin, despite the surgical incision healing well. Microscopic examination revealed cysts lined with stratified squamous epithelium filled with keratin, without adnexal differentiation. The study suggests that the implantation of epidermal fragments into the dermis during surgery may lead to the formation of epidermal cysts and comedones, particularly in dogs affected by hyperadrenocorticism.