Case Report: Diagnosis of a Rare Plaque-Like Dermal Fibroma Successfully Treated With Mohs Surgery

Background: CD34-positive plaque-like dermal fibroma (PDF) is a poorly characterised benign dermal neoplasm that has a wide differential diagnosis. It can be mistaken for other entities on superficial biopsy and be overtreated, leading to unnecessary worry and extensive surgery. Objective: To report on an uncommon presentation of this entity, the histopathologic differential diagnosis of PDF, and a novel treatment method. Methods: Clinical and histopathological information was obtained for a PDF lesion on a 75-year-old man. Results: On superficial biopsy, the PDF lesion was misinterpreted as a possible neurothekeoma. Successful Mohs surgery and genetic testing confirmed the diagnosis of PDF, and the patient received appropriate tissue-sparing surgical management. Conclusion: This case adds to our current knowledge about PDF and highlights the importance of early recognition of these lesions to direct appropriate diagnostic testing (full-thickness biopsy) and management. This case confirms successful management with Mohs surgery.