Dermatofibroma: Reappraisal and Updated Review

Dermatofibromas (DF), also known as fibrous histiocytomas, are common benign cutaneous lesions characterized histologically by dermal proliferation of spindle-shaped fibrocytes, with the overlying epidermis often demonstrating hyperplasia with acanthosis, basal layer hyperpigmentation, and a characteristic "collarette" of epidermal hyperplasia surrounding the lesion. The etiology of DF remains debated, with theories ranging from reactive processes triggered by local trauma, such as insect bites, to spontaneous development. DF typically presents as a hyperkeratotic nodule or plaque, most often on the lower extremities, and can exhibit a wide spectrum of clinical appearances. Variants such as hemosiderotic, epithelioid, aneurysmal, and cellular DF show distinct clinical and histopathological features that may sometimes mimic malignant lesions. Dermoscopic findings can aid in diagnosis, although biopsy is often required for definitive classification. Discrepancies in the literature persist regarding the pathogenesis and classification of DF, and while DF is generally benign, rare cases of metastasizing DF have been reported. This review aims to provide an examination of DF, including its clinical manifestations, etiology, subtypes, histological features, and differential diagnoses. It also discusses dermoscopic findings, controversies in the literature, and current treatment options. A clearer understanding of its diverse presentations, along with refined diagnostic criteria, will enhance clinical management and treatment strategies.