A Solitary Fibrofolliculoma on the Back With a Nevus.

Multiple fibrofolliculomas (FFs) are a major feature for the rare autosomal dominant disorder Birt-Hogg-Dubé syndrome. Individuals with this condition carry a mutation in the FLCN (folliculin) gene that increases their risk for pneumothorax and renal cell carcinoma. Solitary FFs do not have a genetic component to suggest BHD syndrome. However, they are rare, benign tumors with epithelial and connective tissue features, primarily reported on the face, head, and neck. Here, we present the case of 46-year-old woman with a solitary FF on the back coexisting with a nevus. Histological analysis confirmed the diagnosis of FF, characterized by an irregular follicular structure with epithelial cords and an associated fibromyxoid stroma. This case contributes to the limited reports of solitary FFs, highlighting the rare occurrence and unique association with a nevus.