Pancreatic Tail Cyst Causing Hydronephrosis.

Pancreatic cysts are abnormal masses found in the pancreas. They are either cancerous or benign and are mostly found incidentally on imaging. The majority are asymptomatic, but these cysts can sometimes become so large that they obstruct the function of structures around them. In this case, a pancreatic pseudocyst became so large that it caused hydronephrosis. An elderly female presented to a community hospital with abdominal pain. A computed tomography (CT) during that admission noted intraductal papillary mucinous neoplasm with ductal dilatation worrisome for underlying malignancy. An MRI was recommended but could not be performed due to incompatible hardware. The patient's abdominal pain improved, so she was discharged for outpatient endoscopic ultrasound (EUS). Soon after discharge, the patient experienced worse right upper quadrant (RUQ) pain. A repeat CT upon her return to the hospital showed a new pancreatic pseudocyst causing left hydronephrosis. The patient was transferred to a tertiary care center for further management. An esophagogastroduodenoscopy (EGD) was performed, and an extensive peripancreatic fluid collection was identified, measuring approximately 11 cm × 7 cm. A 15 mm Hot AXIOS (LAMS) cystogastrostomy tube was placed, and the cytopathology report was negative for malignant cells. A repeat CT abdomen post-procedure showed near-complete resolution of pseudocyst. A repeat EGD was performed to monitor the cyst and remove the LAMS cystogastrostomy tube. The patient was discharged home with close follow-up with GI. Overall, pancreatic pseudocysts sometimes resolve, but if they do not, they require surgery. In this case, minimally invasive advanced endoscopy using a cystogastrostomy tube relieved the patient's obstruction.