An autopsy case of Merkel cell carcinoma presenting aggressive intraabdominal metastasis and duodenal obstruction.

: A 85-year-old Japanese woman was urgently admitted to our hospital complaining of vomiting 20 months after the initial diagnosis of Merkel cell carcinoma on the right eyelid. The patient died of a huge intra-abdominal mass with complete obstruction of the distal duodenum two months later. On autopsy, the mass measuring 18 x 12 x 5 cm in size was histologically diagnosed as metastatic Merkel cell carcinoma and directly invaded the stomach, pancreas, and distal duodenum.