Malignant melanoma metastasis to pancreas diagnosed by endoscopic ultrasound guided fine needle aspiration Cytology: A case report

Pancreatic metastasis of malignant melanoma is rarely diagnosed on EUS FNAC while the patient is alive. Primary or secondary pancreatic malignant melanoma are rarely described in the literature. Most of the cases have been reported in the literature by surgical pathology. A 52-year-old male patient presented with 3 episodes of pain in abdomen for last 15 days. Patient had history of blackish discoloration with mass in big toe which was amputated 1 year age. On examination, multiple soft to firm non tender nodules palpable over right shin, right thigh and over right scapula. Patient was admitted for evaluation of pancreatic mass. CT abdomen and thorax showed lobulated heterogenous mass replacing pancreas with encasement of splenic vessels. Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) was performed from the mass of the pancreas. A probable cytomorphological diagnosis of malignant melanoma metastatic to pancreas was made. The final diagnosis of malignant melanoma was confirmed by strong positivity of HMB45 and S100 immunocytochemical staining on endoscopic ultrasound-guided fine needle aspiration cytology (EUS-FNAC). We report a very unusual case of malignant melanoma metastatic to pancreas diagnosed by EUS-FNAC. Although this is uncommon in the pancreas, malignant melanoma should be considered in the differential diagnosis of metastatic pancreatic masses on cytology. Keyword: Melanoma, Endoscopic, Cytology and Immunocytochemistry