Chondromyxoid fibroma of the distal phalanx of the great toe: a tumor with unusual histological findings

Chondromyxoid Fibroma of Distal Phalanx of the Great Toe: A Rare Clinical Entity

Chondromyxoid fibroma is a rare benign tumor of cartilaginous origin with myxoid and fibrous components. It accounts for approximately 1% of bone tumors. Metaphysis of long bones is the most common location of this tumor. However, there a few case reports of this tumor arising from epiphysis of short tubular bones of the hand and feet.

An 11-year-old girl presented to our OPD with complaints of pain and a gradually progressive swelling of the right great toe. On examination, the swelling was diffuse with no signs of inflammation. X-ray examination revealed a well-defined, longitudinally oval lytic lesion in the right distal phalanx of great toe, involving the growth plate and, eroding the medial cortex. Computed tomography (CT) scan did not show any evidence of calcification, septations or involvement of soft tissue. Open biopsy and curettage was done and the specimen was sent for histopathological examination. Histopathological examination (HPE) showed a lobular pattern consisting of myxomatous stroma and immature cartilaginous cells in lacunae. The lobules were separated by fibrous septae. It was reported to be Chondromyxoid fibroma. The patient presented six months later with persisting pain and X-ray showed recurrence of the tumor. Hence, complete excision of the tumor was done and the defect was filled using synthetic bone graft. At six months follow up, the patient did not complain of pain and X-rays showed signs of bone formation with incorporation of the graft.

Chondromyxoid fibroma is a low grade tumor, which may demonstrate nuclear atypia histologically and mimic chondrosarcoma. Differentiating these two is of paramount importance to avoid over-diagnosis and aggressive treatment. Recurrence is common with marginal excision and especially in younger patients like in our case. Complete resection is the mainstay of management. Long-term follow up of patients is necessary to watch for malignant transformation, a rare complication. Chondromyxoid fibroma is an extremely rare neoplasm of bone. There are no specific radiologic features, and histopathology provides a definitive diagnosis. It should be considered in differential diagnosis of lytic lesion, and differentiated from other tumors, especially from chondrosarcoma to treat the patient appropriately.

Cystic bone tumors of the foot and ankle

Bone tumors are relatively rare in the foot and ankle region. Many of them present as cystic lesions on plain films. Due to the relative rarity of these lesions and the complex anatomy of the foot and ankle region, identification of such lesions is often delayed or they get misdiagnosed and mismanaged. This review discusses the most common cystic tumors of the foot and ankle including their radiographic features and principles of management.

Chondromyxoid fibroma of the distal phalanx of the big toe

Chondromyxoid fibroma rarely arises in the distal phalanx of the toe. It shows a wide spectrum of histology, mimicking other primary bone tumors. A 40-year-old woman had persistent swelling of her big toe after a minor injury a few years ago before a consultation. A radiographic and magnetic resonance imaging study suggested a highly aggressive tumor. Amputation was performed, and pathology of the lesion showed chondromyxoid fibroma.

Chondromyxoid fibroma of the foot and ankle: 40 years' Scottish bone tumour registry experience

Ten cases of histologically proven chondromyxoid fibroma (CMF) of the foot and ankle with a mean follow-up of 6.1 years were retrospectively reviewed using the Scottish Bone Tumour Registry. The patients' mean age was 19 years; there were six males and four females. The anatomical locations were five phalangeal, three metatarsal, one tarsal affecting body of os calcis and one distal tibial. The median delay in presentation was 4.5 months. The modes of presentation were pain only (n=4), painful lump (n=4) and painless lump (n=2). The typical radiological finding was an expansile, lobulated, cystic lesion. Cortical erosion was documented in 80% patients. In four cases, curettage alone was carried out, while five patients underwent curettage along with autogenous bone grafting. One patient with distal phalangeal CMF had a primary toe amputation. Two patients had recurrences 9 and 16 months after their initial curettage. Both of them were males with proximal phalangeal CMF, associated with cortical erosion. Foot and phalangeal CMF initially treated with curettage only should be closely followed up, as we observed a 20% recurrence rate within a 2-year period. Cases featuring cortical erosion require thorough curettage and may require autogenous bone grafting to prevent fracture.