Fibroma of tendon sheath is a benign tumor that presents as a small subcutaneous nodule that slowly increases in size.^[1] The tumors often have a multinodular growth pattern, with individual nodules being composed of bland, slender, spindle-shaped cells (myofibroblasts) in a dense, fibrous matrix.”^[2] A common microscopic finding is the presence of elongated, slit-like blood vessels.^[2] The lesions nearly always arise in the distal portions of the extremities.^[2] They often occur on the fingers, hands, toes, or feet. Although they are benign, they may recur after surgical excision in up to 40% of people.^[1]

Fibroma of tendon sheath
Photomicrograph of a fibroma of tendon sheath of the finger
Specialty	Plastic surgery

Although they may be regarded as a tumor of the skin, the lesions arise from tendons and aponeuroses in superficial sites, and are therefore properly classified in the category of soft-tissue tumor.^[2] The World Health Organization in 2020 reclassified these tumors as a specific, benign tumor type in a broad category of soft tissue neoplasms termed fibroblastic and myofibroblastic tumors.^[3]

The biological nature of fibroma of tendon sheath is not known, but the category appears to comprise a number of different pathological processes.^[2] It is considered that about one-third of the lesions in this category may be acral variants of the entity nodular fasciitis.^[2]