Unusual distant metastatic lesion from buccal carcinoma mimics refractory gouty arthritis

Distant metastasis to small bones from buccal mucosal cancer was extremely rare. We reported a rare case of buccal carcinoma with an unusual metastasis to the calcaneus. Subsequently, this metastatic lesion directly involved the left ankle joint. As a result, it initially presented with a monoarthritis mimicking refractory gouty arthritis. Moreover, it transformed to an acute toxic reaction mimicking infectious monoarthritis. This case confirmed our clinical experience that cancer patients presented with common symptoms and refractory to conventional management might have an underlying malignant disease in nature.