Rare case of fibroma of the tendon sheath in a pediatric patient

Abstract

Fibroma of tendon sheath (FTS) is a benign uncommon soft tissue tumor that presents as a solitary, firm, slow-growing painless nodule. This tumor arises from the synovium of the tendon sheath that occurs mostly around small joints such as the fingers, hands, and wrist. This soft tissue tumor rarely arises around large joints such as the knees, shoulders, elbows, and ankles with intra-articular or extra-articular involvement. It most commonly presents as a painless, slow-growing tumor with small nodular swelling and is often seen in adults 20-50. Our report reviews a unique case of fibroma of the tendon sheath in a pediatric patient. A 12-year old right-hand dominant female presented to the clinic with a mass located on the volar region of the proximal phalanx of the right long finger. This mass was present for 6 months and progressively increased in size. It caused intermittent pain, with prolonged activity. An ultrasound displayed a 1.3 cm mass around the proximal portion of the right long finger, which was consistent with a giant cell tumor versus a neuroma. Surgical dissection was performed and the mass was about 1 cm in diameter and emanated deep to the flexor tendons in the flexor sheath. When the patient followed up in the clinic postoperatively, there was no tenderness of the hand and mild tenderness over the volar portion of the right long finger. There was no palpable mass or angular deformity noted and the patient was neurovascularly intact. Clinical presentation, surgical management, recurrence, differential diagnosis, progression, and growth of the mass make this case unique. Typically, this is seen in the young and middle-aged demographic and reported in a 3:1 male to female ratio. The differential diagnosis for FTS includes giant cell tumor, mucinous cyst, lipoma, epidermal cyst and leiomyoma. Future studies should investigate other forms of management for Fibroma of the tendon sheath.