Skeletal Muscle Metastasis Mimicking a Shoulder Effusion

Urothelial carcinoma is a rare cause of metastatic disease appearing in skeletal muscle. We describe a rare presentation of malignancy mimicking a shoulder effusion. A 65-year-old man presented with ongoing swelling and dysfunction of his right shoulder. He had a history of urothelial cell carcinoma treated by surgical resection 8 months previously. Two months before presentation to the rheumatology service he developed progressive …