ARRS COTW- November 5, 2018

MUSCULOSKELETAL IMAGING: Metabolic/Hematologic

Case Author: Daniel E. Wessell, MD, PhD, Mallinckrodt Institute of Radiology at Washington University in Saint Louis

History

8-year-old boy with distal right femur pain after recent resection of a lesion from the proximal right tibia.

Imaging Findings

Anteroposterior (A) and lateral (B) radiographs of the right knee show dense metaphysial bands and dense zones of provisional calcification at all three growth plates depicted but especially in the distal femur. Mild physial widening (arrows, A) is evident in the distal femur. Surgical changes from recent resection of a proximal tibial lesion also are evident.

Diagnosis

Methotrexate osteopathy

Teaching Points

Methotrexate osteopathy is an uncommon complication of methotrexate therapy, which can cause severe pain.

The radiographic findings of methotrexate osteopathy resemble those of scurvy: osteopenia, thickened and dense provisional zones of calcification, and growth arrest lines.

Heavy metals can inhibit osteoclastic remodeling but not osteoblastic activity, resulting in dense metaphysial bands.

Because of lack of mineralization of cartilage, the classic radiographic appearance of rickets is widening of the growth plates and metaphyses with cupping of the metaphyses and bowing of the weight-bearing bones.

MUSCULOSKELETAL IMAGING: Metabolic/Hematologic

History

Imaging Findings

Diagnosis

Teaching Points

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