Epidemiology
On the skin it is very common and is called a dermatofibroma. The variant that belongs to this family of soft-tissue tumors is the deep one (deep benign fibrous histiocytoma), considerably rarer and managed more carefully. When it is superficial and typical it is usually managed simply; deep or atypical growth requires ruling out more aggressive diagnoses.
Basic features
The cutaneous dermatofibroma presents as a firm, small, slow-growing nodule in the skin. The deep variant, by contrast, forms a mass in the subcutaneous tissue or within the muscle and, because it is rare and resembles other lesions, requires pathological confirmation before surgery is decided.
Usual treatment
Observation, or local excision if it hurts, bleeds, changes, or the diagnosis is unclear.
Outcomes and prognosis
The prognosis is excellent; deep variants require more care because of a greater chance of recurrence.