Cutaneous metastases mimicking keratoacanthoma

A 60-year-old man, with history of pulmonary tuberculosis treated and chronic obstructive pulmonary disease, presented with multiple, round skin-colored nodules with a central keratin plug were observed in the left parietal area and the left shoulder. In addition, there were palpable enlarged lymph nodes around the inguinal region. A biopsy of one of the lesions showed histological characteristics of a metastatic adenocarcinoma. Computer tomography of thorax showed lesions in the lung. Subsequently, a bronchoscopy revealed a mass in the left lung. Biopsies of the bronchic mass showed an adenocarcinoma resembling the previous skin tumor biopsy. The tumor cells of both lesions expressed cytokeratin 7, but neither expressed cytokeratin 20 nor thyroid transcription factor, so a highly differentiated adenocarcinoma was diagnosed. After diagnosis of a metastatic bronchial adenocarcinoma, the patient was transferred to the department of Oncology, where chemotherapy was started. The patient is under regular monitoring. Metastatic cancer to skin is not a frequent occurrence. It can present with several morphologies including, rarely, keratoacanthoma-like lesions. This included patients with primary tumors of the breast, bronchus, cartilage, esophagus and pleura.