A Case of Squamous Cell Carcinoma on the Buttock Complicated with Hypercalcemia, Probably Arising from a Scar of Tuberculosis Cutis

Abstract

A 57-year-old man had been aware of a verrucous nodule, 2-3 cm in size, on the left buttock since childhood. The nodule increased in size and formed an ulcer in November 2006. He ignored it for a while. Then in March 2007 he visited a nearby physician because of difficulty in sitting. Biopsy revealed a well-differentiated squamous cell carcinoma (SCC), and he was referred to our hospital immediately. Physical examination revealed a tumor on his left buttock, 130×90×15 mm in size, with ulcerations and an irregular surface. It bled easily and was surrounded by a scar. He had complained of general fatigue recently. Results of laboratory examination indicated hypercalcemia and elevations of parathyroid hormone-related protein (PTH-rP) and SCC-related antigen. QuantiFERON-TB2G (QFT) was positive. Administration of pamidronate (bisphosphonate) and elcatonin with fluid infusion normalized serum calcium values. The tumor was excised, and chemotherapy was performed. No recurrence or metastasis of the tumor has been detected 11 months after the operation. Postoperative histopathological examination revealed caseation granuloma with Langhans giant cells in the lymph nodes in the pelvic cavity. This fact, together with the atrophic scar around the tumor, suggested the diagnosis of tubercular lymphadenitis and tuberculosis cutis. We considered that the etiological factors of the SCC in this patient might involve tubercular diseases.