Juvenile Hyaline Fibromatosis Presenting as Progressive Flexion Contracture of the Middle Finger in a Child: A Case...

Juvenile fibromatosis is a rare benign fibroproliferative condition that may cause functional impairment when affecting the upper extremity. Deep involvement of flexor tendons in the hand is particularly unusual. An 8-year-old girl presented with a 6-year history of progressive flexion contracture of the left middle finger, causing inability to extend or grasp objects. Examination showed severe proximal interphalangeal and distal interphalangeal contractures of the middle finger and mild proximal interphalangeal contracture of the index finger. Radiographs revealed deformity without bony abnormality. Intraoperatively, extensive fibrosis and thickening of the flexor tendons of the middle and ring fingers were found (zones III-V), with adhesions and tendon shortening. Adhesiolysis, excision of fibrotic tissue, and tendon lengthening were performed, achieving full passive extension. Histopathology confirmed juvenile fibromatosis. Postoperative splinting and physiotherapy resulted in functional improvement. Juvenile fibromatosis is a rare myofibroblastic proliferation that, although histologically benign, is characterized by locally aggressive growth and a high propensity for recurrence. Its presentation within the deep flexor tendons of the hand is exceedingly uncommon and can easily be misdiagnosed as more frequent pediatric conditions, such as camptodactyly or congenital trigger finger. In this case, the six-year progression of the contracture led to significant adaptive shortening of the tendons, necessitating adhesiolysis and tendon lengthening. Juvenile fibromatosis of the flexor tendons is an exceedingly rare cause of progressive digital contracture in children. Early recognition and surgical intervention with rehabilitation can preserve hand function.