Metastatic malignant melanoma of the gallbladder diagnosed by cytology of endoscopic naso-gallbladder drainage fluid

An 82-year-old man was referred to our institutionfor an examination on his cheek skin pigmentationwhich directly infiltrating to the parotid gland. Thepatient did not complain of any symptoms otherthan the recent increase in size of his skin lesion(Fig. 1a), and his physical condition was good. Hisdisease history was unremarkable, and there was nofamily history of MM. On admission, his blood testrevealed normal hepatic enzymes including lacticdehydrogenase (LDH) and tumor markers such ascarcinoembryonic antigen (CEA) and carbohydrateantigen 19-9 (CA19-9), however, only serum 5-S-cysteinyldopa was abnormally high (18.5 nmol/L