Response to a Novel Multitargeted Tyrosine Kinase Inhibitor Pazopanib in Metastatic Merkel Cell Carcinoma

Abstract

A 69-year-old woman presented with a 2-year history of gradually increasing scalp swelling in December 2001. The patient was in good general condition, but physical examination revealed a 5-cm fleshy tumor on the right scalp, with pathology consistent with Merkel cell carcinoma on excisional biopsy. A metastatic work-up, including computed tomography (CT) of the thorax and abdomen, mammography, and gastroscopy, was negative, and the patient underwent a subsequent wide excision with superficial skin graft. No adjuvant radiotherapy was administered at this time. In August 2002, the patient had a local recurrence of a bulky 12-cm mass fixed to the skull, and biopsies of the right upper deep cervical and supraclavicular lymph nodes were inconclusive for involvement. The tumor was inoperable, and the patient underwent radical radiotherapy for a total of 70 Gy, with excellent response at all tumor sites. In March 2003, two small nodules developed in the field, which were believed to represent either soft tissue radionecrosis or possibly a second local recurrence.