Diagnosis of a metastatic phyllodes tumor of the pancreas using EUS-FNA.

CONTEXT Phyllodes tumors are rare fibro-epithelial lesions which make up less than 1% of all breast neoplasms. After curative surgery, distant metastases may occur without local recurrence; the typical sites of the metastases being the lungs and the bones. Endoscopic ultrasound (EUS) and EUS-guided fine needle aspiration (EUS-FNA) has emerged as the leading modalities for the evaluation of pancreatic masses. Until now, there have been no published reports on the use of EUS-FNA to diagnose recurrent phyllodes tumors metastatic to the pancreas. CASE REPORT A 55-year-old female was hospitalized for the problem of painless obstructive jaundice due to a pancreatic head mass causing biliary obstruction. She had a past history of a left breast phyllodes tumor treated with mastectomy. The diagnostic dilemma was whether this was a case of primary pancreatic cancer or a recurrent phyllodes tumor presenting as a pancreatic metastasis. EUS-FNA of the mass was performed and it revealed a metastatic phyllodes tumor. The patient was treated with palliative biliary stenting and was referred for palliative chemotherapy. CONCLUSION This is the first report of a recurrent phyllodes tumor metastatic to the pancreas diagnosed using EUS-FNA. It highlights the utility of EUS-FNA in characterizing the nature of pancreatic head masses.