Key Clinical MessageBy reporting this case, we hope to emphasize the importance of maintaining a high index of clinical suspicion for the early recognition of RS3PE in patients presenting with atypical symptoms of PMR and underlying history of malignancy.AbstractRemitting seronegative symmetrical synovitis with pitting edema is a rare rheumatic syndrome of unknown etiology. It shares qualities with many other common rheumatological disorders such as rheumatoid arthritis and polymyalgia rheumatica, making diagnosis especially challenging. RS3PE has been speculated to be a paraneoplastic syndrome, and those cases associated with underlying malignancy have shown to respond poorly to conventional treatment. Therefore, it is advisable to routinely screen patients with malignancy and presenting with RS3PE for cancer recurrence, even if in remission.