Pedal acrometastasis secondary to urothelial carcinoma masquerading as Charcot arthropathy in a patient with diabetes

Abstract

A woman in her 80s with known diabetes mellitus and bladder cancer presented to her general practitioner (GP) with pain and swelling in her left foot following trauma. Initial radiographs were reported as normal, prompting a diagnosis of a simple sprain and conservative management. Three months later, the patient was referred to the orthopaedic team due to progressively increasing pain and swelling. Repeat X-rays revealed lytic lesions in both the talus and navicular bones; MRI confirmed the presence of a lytic and proliferative defect in the mid-foot, which was reported as acute Charcot arthropathy with superimposed infection. This was also considered the most likely diagnosis when imaging was reviewed in two separate multidisciplinary team) meetings. However, biopsy demonstrated that the cause of the presentation was in fact acrometastasis from urothelial carcinoma, an infrequently described entity.