CARTAS AL DIRECTOR

 

Pancreatic adenocarcinoma mimicking intraductal papillary mucinous tumor (IPMT)

Adenocarcinoma pancreático simulando tumor mucinoso papilar intraductal

 

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Palabras clave: Adenocarcinoma pancreático. Intraductal. Papilar. Mucinoso.

Key words: Pancreatic adenocarcinoma. Intraductal. Papillary. Mucinous.

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Sr. Director:

A 52-year-old male was admitted to hospital because of a persistent abdominal pain and weight loss in recent 6 months. Jaundice developed since 2 weeks ago. He did not have history of diabetes or other medical diseases. A fixed, firm, non-tender palpable mass was noted over right upper quadrant on examination of his abdomen. The total bilirubin level was 9.1 mg/dL on admission, with moderate elevation of liver enzyme. Blood sugar was 291 mg/dL. Other blood tests were nonspecific. A computed tomography (CT) scan of the abdomen showed a tumor mass from pancreatic head to tail with marked dilatation of the main pancreatic duct, and the grapelike multicystic dilatation of the branch ducts (white arrow). Severe parenchymal atrophy of pancreas was present (Fig. 1A). Intraductal papillary mucinous tumor (IPMT) was diagnosed under the characteristic imaging findings. Exploratory laparotomy with total pancreatoduodenectomy was done and the specimen showed a clustered cystic lesion communicating with the main pancreatic duct. The resected pancreatic tissue was sent for pathological study. The permanent pathological picture showed mucinous adenocarcinoma characterized by dysplastic tumor nests with nuclear pleomorphism, increased nucleus-to-cytoplasm (N/C) ratio, and hyperchromatism (Fig. 1B). Immunohistochemical stains showed that the cells were positive for CK7 and CK20, monoclonal antibodies for labeling epithelium of gastrointestinal tract, especially adenocarcinoma. The post-operative diagnosis was revised.

Pancreatic adenocarcinoma is the cancer arising from pancreatic ducts and the most common type of pancreatic cancers. This disorder is among the most aggressive of all cancers because the majority of pancreatic cancers appear in the late stage of disease. Most of the tumors locate in the head of the pancreas. The common features pancreatic adenocarcinoma on CT scan include alterations in morphology of the gland, obliteration of peripancreatic fat, loss of sharp margins with surrounding structures, involvement of adjacent vessels and regional lymph nodes, and obstruction of the common bile duct (CBD) (1). The treatment of pancreatic adenocarcinoma includes surgical resection, chemotherapy, or radiotherapy depending on the clinical staging. IPMT is a relative benign disease which has the intraductal and papillomatous growth pattern. The tumor is associated with excessive mucin secretion and results in progressive ductal dilatation or cyst formation. The typical CT findings of IPMT demonstrate diffusely dilated main duct and grapelike multicystic dilatation of the branch ducts. Total resection of pancreas is suggested in cases of IPMT. We present this rare case that pancreatic adenocarcinoma mimics IPMT with such interesting CT figure. The preoperative biopsy in such case may help for diagnosis before surgical intervention and influence the decision making of the surgeon.

 

S. Y. Chen, C. H. Lin, J. C. Yu and D. C. Chan

Division of General Surgery. Department of Surgery. Tri-Service General Hospital.
National Defense Medical Center. Taipei, Taiwan, R.O.C.

 

Reference

1. Clarke DL, Thomson SR, Madiba TE, et al. Preoperative imaging of pancreatic cancer: a management-oriented approach. J Am Coll Surg 2003;196 (1): 119-29.