Plasma cell leukaemia presenting with polyarthralgia and phalangeal lytic lesions

We present the case of a patient who presented with small joint polyarthralgia and mild lymphocytosis. The patient was subsequently diagnosed to have plasma cell leukaemia. Skeletal survey showed bony lytic lesions in the hands and feet with no skeletal lesions elsewhere. The most common sites of bony involvement in plasma cell dyscrasia are skull, vertebrae, ribs and long bones. Although it is quite unusual for plasma cell leukaemia or myeloma to involve solely small joints of hands and feet, we suggest plasma cell dyscrasia should be kept in the differential diagnostic list for polyarthralgia in adults if usual causes are ruled out.