Acute arthritis as an unusual complication of malignancy

SUMMARYA 59‐year‐old man presented with an inability to weight‐bear due to an acute, red, hot, swollen knee joint which was subsequently found to be due to a malignant joint effusion consequent to colonic carcinoma. Treatment with radiation therapy relieved his symptoms. A review of the literature reveals that malignant joint effusion is rare and this is only the third reported case secondary to colonic carcinoma.