Presentation
Known case of multiple myeloma with painful right thumb swelling.
Patient Data
The thumb's proximal phalanx shows an expansile lytic lesion with severe cortical narrowing and endosteal scalloping, accompanied by adjacent soft tissue swelling. The metacarpophalangeal and interphalangeal joints are intact.
Case Discussion
This case demonstrates an expansile lytic thumb lesion in a known patient with multiple myeloma.
Most bony lesions in multiple myeloma are purely lytic, sharply defined or punched out, with endosteal scalloping when abutting the cortex. It should be noted that the distribution of multiple myeloma mirrors that of red marrow in older individuals. Thus, it is mainly encountered in the axial skeleton and proximal appendicular skeleton. Distal extremities are rare locations for involvement in multiple myeloma.