Renal cell carcinoma presenting as a cutaneous horn and nodules on the gingiva and scalp

A 63-year-old man presented with a pulsatile cutaneous horn on the nose and multiple angiomatous nodules on the gingiva and scalp, which appeared over 2 months. He had severe hypercalcaemia, lytic lesions in multiple bones and acute kidney injury. Excision biopsy from the gingival nodule showed a clear cell neoplasm. The bone marrow showed atypical cells with similar morphology. Imaging showed a 7 cmx7.5 cm mass at the upper pole of the left kidney with metastases to the bones, liver and lung. Immunohistochemistry was consistent with metastatic renal cell carcinoma. Renal cell carcinoma presenting as a cutaneous horn is extremely rare and to the best of our knowledge only one other case was found in the literature. There was visible regression in the size of the cutaneous horn and nodules following initiation of pazopanib therapy. However, he succumbed to his illness a month later.