CLINICAL PRESENTATION AND LITERATURE REVIEW: MUSCLE METASTASIS IN UPPER TRACT UROTHELIAL CARCINOMA

Urothelial carcinoma often metastasizes by lymphatic pathways to locations including lymph nodes, bone, and liver. Similar to other cancers, muscle metastasis is uncommon. M.M., a 68-year-old with a history of hypertension, dyslipidemia, and thyroidectomy, has been suffering from lumbar discomfort since April 2023. CT scans revealed secondary lesions and infiltrating urothelial neoplasia in the kidney, renal pelvis, and abdomen. An FDG PET scan confirmed right renal neoplasia. The patient was treated with platinum-based chemotherapy, followed by avelumab. In the sixth cycle, the patient experienced severe pain in the left thigh and a painful mass.