Mucinous Cystic Neoplasm in a Patient With Polycystic Kidney Disease

Abstract

Mucinous cystic neoplasms (MCN) are thick-walled cysts with occasional septations that are filled with thick mucus or hemorrhagic material and have no connection to the pancreatic duct (PD). They can arise from the pancreas, ovaries, appendix and the lungs. A pancreatic MCN is exceedingly rare and the majority of these are benign, but they can have malignant potential. We present a unique case of a pancreatic MCN in a patient with autosomal dominant polycystic kidney disease (ADPKD). A 72-year-old male with a past history of renal transplant in 1987 and 2001 secondary to ADPKD, coronary artery disease with coronary artery bypass graft in 2008, diabetes mellitus and hypertension was found to have an evidence of chronic pancreatitis and a 6.5 x 6.5 cm cystic structure in the pancreatic body (Figure 1, 2) on a CT Scan of the abdomen performed during a hospitalization for pneumonia. A follow-up MRI of the abdomen showed an atrophic pancreas with innumerable cysts with the largest cyst measuring 6.7 cm. The patient presented to the gastroenterology clinic after 12 months with complains of epigastric pain, and weight loss. Subsequently a repeat MRI of the abdomen revealed an increase in the size of numerous cystic structures with the largest lesion measuring 7.5 x 7.5 x 8 cm. He underwent an endoscopic ultrasound with aspiration of the largest cyst. The fluid amylase level was > 12,000 U/L, and the carcinoembryonic antigen level was 1383 ng/mL suggestive of MCN. Histology revealed histiocytes, proteinaceous debris, and intestinal-type cyst epithelial lining without high grade dysplasia or malignancy. After a multidisciplinary discussion at our tumor board, the patient was deemed not to be a surgical candidate, nor a candidate for cyst ablation in presence of ongoing recurrent chronic kidney disease, multiple advanced comorbidities, absence of high-grade dysplasia or malignancy within the cystic lesion in addition to the proximity of the largest cyst to the main PD.1441_A.tif Figure 1: No Caption available.1441_B.tif Figure 2: No Caption available.ADPKD occurs in 1/400 - 1/1000 people in general population. Besides renal cysts, there are several extrarenal manifestations that have been described, including pancreatic cysts in 9-36% of the cases. Patients with ADPKD with pancreatic cysts are usually asymptomatic, but rarely these cysts can cause pancreatitis from compression of the PD as in our case, or may evolve into malignancies such as intraductal papillary mucinous neoplasm or cystadenocarcinoma.1441_C.tif Figure 3: No Caption available.