Radiography and MRI of the left lower tibia demonstrated features of a chondromyxoid fibroma (CMF), with fracture of the lower end of the tibia. Grossly, the specimen demonstrated multiple gray-white fragments, with focally identifiable firm periosteal bone attached over the fragments. The cut surface of the fragments showed a shiny myxoid appearance with intervening firm gray-white areas.
Histopathologic examination showed a lobulated lesion. The lobules of chondromyxoid materials were separated by thin cellular septae composed of innocuous-looking spindle cells, with interspersed small vessels and few osteoclastic giant cells. The chondromyxoid component showed varying cellularity. The periphery of the lobules was more cellular in appearance, and the cells were predominantly spindle in shape.
In the center, the cells had a moderate amount of eosinophilic cytoplasm, whereas a few others were stellate-shaped. Chondrocytes were also identified. No evidence of multinucleation within the lacunae or significant nuclear pleomorphism was noted. The spindle-cell component also did not show any pleomorphism or mitotic activity (Figure 4). These features, correlated with the radiologic findings, were indicative of CMF.
CMF is a benign tumor of bone that was first described by Jaffe and Lichtenstein in 1948.[1,2] This lesion accounts for 1% of all bone tumors and 2% of all benign bone tumors. It is most commonly found in the long tubular bones, especially the tibia and femur near the knee joint; however, the overall most common site is the proximal tibia, which is affected in 30% of cases. Approximately 25% of cases occur in the flat bones.[3,4] The small bones of the lower limbs may also be affected. The skull, spine, and bones of the upper extremity are relatively uncommon sites for this lesion.
Patients with this condition range from 3 to 70 years of age; however, most cases are seen in patients aged 10-30 years. A male predominance has been described (male-to-female ratio, 2:1).[3,5] The most common presenting symptoms are pain and swelling, which are noted in 85% and 65% of cases, respectively; the third most common symptom is restriction in joint movement. The pain is usually mild, transient, and of long duration. Approximately 15% of cases are discovered incidentally on radiologic examination. Pathologic fracture may occur in 5% of cases, causing significant morbidity.
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Cite this: Prasenjit Das, Elanthenral Sigamani. A 13-Year-Old Boy With Recurrent Lower Leg Pain - Medscape - Jun 13, 2017.