P2192 - Not All Pancreatic Masses Are Created Equal: Occult Melanoma in a Pancreatic Mass

Thao T. Nguyen, DO¹, Gabriel Gonzales, DO¹, Shilpa Madadi, MD², Long Hoang, DO³, Srujana Dasari, MD^1
1Medical City Fort Worth, Fort Worth, TX; ²John Peter Smith Hospital, Fort Worth, TX; ³UNT Health Science Center, Fort Worth, TX

Introduction: Pancreatic metastases from other malignant primary tumors are a rare clinical condition and account for approximately 2% of all pancreatic malignancies. Common primaries which metastasize to the pancreas include renal, breast, lung, and colon cancers; even rarer is a primary malignant melanoma. Here, we present a unique case of a patient who was diagnosed with metastatic melanoma to the pancreas, without an identifiable primary lesion.

Case Description/Methods: A 48-year-old Norwegian male without relevant past medical or social history presented to our ED for evaluation of a 25-lb weight loss over one month, associated with vague upper abdominal discomfort and dark urine. Labs revealed elevated liver enzymes in a mixed pattern, with total bilirubin level 1.8 mg/dl (direct predominant). A contrasted CT abdomen/pelvis demonstrated widespread hyperdense hepatic and splenic nodules with a necrotic 2.8cm pancreatic body mass with surrounding lymphadenopathy suggestive of metastatic disease. Tumor markers including CEA, CA 19-9, and AFP were all unremarkable. Evaluation with endoscopic ultrasound revealed a well demarcated hypoechoic/anechoic lesion with both cystic and solid components noted in the body of the pancreas, measuring 3.4 x 2.7cm. Fine needle aspiration of the pancreatic lesion as well as visualized hepatic lesions and celiac lymph nodes revealed metastatic melanoma. Detailed medical history-taking and a thorough skin examination resulted in no concerning lesion which could be biopsied. His family history was significant for an unknown skin cancer in his mother. Options for palliative chemotherapy were discussed with the patient, however, he ultimately decided to forgo treatment. He expired within months of diagnosis due to complications of multiorgan failure from rapid progression of metastatic disease.

Discussion: Melanoma is an aggressive malignancy with rapid metastatic potential, carrying a poor prognosis. Occult melanomas are especially dangerous as a primary lesion is not apparent, thus increasing the risk of metastatic lesions at diagnosis, as was the case with our patient. A pancreatic mass is an atypical presentation of metastatic melanoma and should be considered in the differential diagnosis when evaluating pancreaticobiliary lesions. Early diagnosis of an isolated pancreatic metastatic melanoma can alter the treatment plan as surgical resection can be an option; unfortunately this was not the case for our patient who presented with far too advanced metastatic disease.



Disclosures:


Thao T. Nguyen, DO¹, Gabriel Gonzales, DO¹, Shilpa Madadi, MD², Long Hoang, DO³, Srujana Dasari, MD¹. P2192 - Not All Pancreatic Masses Are Created Equal: Occult Melanoma in a Pancreatic Mass, ACG 2021 Annual Scientific Meeting Abstracts. Las Vegas, Nevada: American College of Gastroenterology.