Polymyalgia Rheumatica Associated with Ascending Colon Cancer, that was Difficult to Differentiate from Tumor-related Syndrome: A Case Report

Abstract

A 60-year-old man with ascending colon cancer and multiple liver metastases had undergone laparoscopic ileostomy 2 years ago. He had received postoperative chemotherapy, however, his general condition deteriorated, and he had been initiated on BSC 6 months ago, along with oral oxycodone for pain control of systemic joint pain. We considered that the pain was caused by tumor-related syndrome, and increased the amount of oxycodone to achieve satisfactory pain control. However, the pain control remained poor, and the patient became drowsy and inarticulate. Joint ultrasonographic examination revealed tendon sheath synovitis of the long head of the biceps, and as the symptoms met the Bird diagnostic criteria for polymyalgia rheumatica (PMR) and the ACR/EULAR classification, we diagnosed the patient as having PMR. Thereafter, we started the patient on prednisolone 10 mg/day, which resulted in remarkable improvement of the symptoms, allowing the oxycodone dose to be reduced and resolution of the various side effects of that drug. Thereafter, the patient’s condition remained stable under a small daily dose of the steroid.

In patients with malignancies, it is often difficult to judge whether multiple joint pain is caused by tumor-related syndrome or comorbidities. It is necessary to pay attention to the possible presence of comorbidities, such as PMR, as the cause of multiple joint pain before increasing the opioid dose, which could, in fact, deteriorate the quality of life.