Working Diagnosis:
Right proximal humeral chondromyxoid fibroma with Salter Harris I fracture of proximal humerus

Treatment:
The patient underwent open biopsy, curettage, and bone grafting without complications. The lesion involved the diaphysis and epiphysis and crossed the physis. Pathology confirmed chondromyxoid fibroma. At follow-up, he reported no pain, the incision was clean, he had full range of motion, and he required no pain medications.

Outcome:
He was advised to use a splint for comfort, perform daily gentle range of motion, and avoid weightbearing for six weeks. At four weeks postoperatively, the patient was doing well with no complications. He was cleared for light sports at six weeks and instructed to avoid high-impact activity for three months. Imaging at three months demonstrated good healing of the fracture without evidence of reccurence. A nine-month follow-up was scheduled.

Author's Comments:
Chondromyxoid fibroma (CMF) is a rare benign lesion, representing less than 1% of bone tumors. It occurs most often in patients between 10 and 30 years old, often in the metaphysis of long bones. A decrease in range of motion, joint effusion, and pathologic fractures are uncommon. Case series report the tibia as most frequently involved, followed by the ilium, ribs, and distal femur. Chondroblastoma is more often localized in the humerus, whereas CMF is rarely seen there, making this humeral case unusual. Histology shows lobules of fibromyxoid tissue with myxoid stroma and stellate cells. Treatment is typically curettage and bone grafting with recurrence rates up to 25%. Surgical management and long-term follow-up are recommended. <br> <br>Growth arrest from chondromyxoid fibroma itself is not documented in the literature, despite the tumor's predilection for the metaphyseal region near growth plates in skeletally immature patients. However, surgical treatment of CMF in children with open physes carries theoretical risk of growth disturbance. We were not overly concerned about growth arrest in our patient given his growth plate was already closing.

Editor's Comments:
Extremity pain in young patients, in particular with a history of trauma, merits screening plain radiographs. When x-rays are suspicious for pathologic fracture, additional advanced imaging and a multidisciplinary approach to management should be pursued as was done in this case. It can easily be mistaken on imaging for other conditions such as a non-ossifying fibroma, chondroblastoma, or even chondrosarcoma Local recurrence is possible, for which some have advocated for en bloc resection to decrease this risk. Premature physeal closure should be considered with physeal fractures in young patients, and knowledge of expected age of closure of various physes helps in guiding follow-up.

References:
Karaca MO, Özyıldıran M, Alizade R, Başarır K, Yıldız HY. Chondromyxoid fibroma: A retrospective evaluation of 31 cases. Jt Dis Relat Surg. 2024 Apr 26;35(2):377-385. doi: 10.52312/jdrs.2024.1620. Epub 2024 Apr 26. PMID: 38727118; PMCID: PMC11128956. <br> <br>Nishio J, Shinohara Y, Chijiiwa Y, Aoki M. Chondromyxoid Fibroma: An Updated Review. In Vivo. 2026;40(2):692-703. doi:10.21873/invivo.14231 <br> <br>Tomazini ACC, Carniel JP, da Cunha LAM. Chondromyxoid fibroma of the distal fibula in a pediatric patient: a case report. Rev Bras Ortop. 2013;48(6):563-566. Published 2013 Dec 19. doi:10.1016/j.rboe.2013.12.005

Return To The Case Studies List.