A Case of Cutaneous Fistula of the Chest Presenting as a Fixed Nodule after Blunt Chest Trauma

An 83-year-old man presented with an intermittently bleeding fixed nodule on the left side of the chest for 2 months. Due to the clinical suspicion of metastatic cancer or a ruptured epidermal cyst, a punch biopsy was performed, which revealed granulation tissue. During surgical excision, a connection between the granulation tissue and the deeper structure was confirmed. Based on the clinicopathological findings, a cutaneous fistula was suspected; a detailed history revealed that he had experienced blunt chest trauma in a motorcycle accident 2 months before. Subsequent chest computed tomography showed soft tissue infiltration in the left sixth rib. Finally, the patient was diagnosed with a cutaneous fistula and underwent resection of the left sixth rib and costal cartilage. Cutaneous fistulae rarely occur in the chest. In cases where a recalcitrant inflammatory nodule is observed on the chest, the patient's trauma history and ordinary medical history should be evaluated to rule out a cutaneous fistula.