Dermatofibroma
Pronunciation: der-mah-toh-fy-BROH-mah
A common, benign fibrous nodule of the dermis, typically presenting as a firm, hyperpigmented papule on the lower limbs, often displaying a characteristic dimple sign on lateral compression.
Full Definition
Dermatofibroma (also known as a benign fibrous histiocytoma) is a reactive or neoplastic fibrohistiocytic proliferation within the dermis, most frequently encountered on the lower legs of adults. The lesion is typically 0.5–1.5 cm, dome-shaped, and indurated, with overlying skin showing varying degrees of hyperpigmentation. The 'dimple sign' or 'Fitzpatrick sign' — inward dimpling on lateral compression — is a pathognomonic clinical feature. Editors must not confuse 'dermatofibroma' with 'dermatofibrosarcoma protuberans' (DFSP), which is a locally aggressive malignant tumour and a clinically and editorially distinct entity.
Usage
Usage note: Never abbreviate to 'DF' without first defining the term, as this could be confused with DFSP (dermatofibrosarcoma protuberans). The two are clinically and histologically distinct, and conflation is a serious editorial error.
In Context
- "The biopsy confirmed a dermatofibroma with characteristic storiform architecture and overlying epidermal hyperplasia." — Histopathology report
- "Reviewers noted that the manuscript used 'dermatofibroma' and 'dermatofibrosarcoma protuberans' interchangeably in the introduction, a clinically significant error requiring correction." — Peer review comment