Duodenal adenocarcinoma

Clinical History

Abdominal colic pain to the rigth lower and hypogastric quadrants.

Imaging Findings

A 78-years old man, with a history of gastroduodenitis, vagotomy for duodenal ulcer and resection of a large duodenal polyp, was referred to Surgery Division, for abdominal intermittent pain to the right lower and hypogastric quadrants. The physical examination was unremarkable. An esophago-gastro-duodenoscopic examination (EGDS) detected a lobulated, soft tissue mass, with a bleeding and ulcerated overlying mucosa. It was extended from the duodenal bulb until the lower duodenal flexure. An abdominal ultrasonography showed a global heterogeneous echogenicity of the pancreatic gland without other focal lesions.An endoscopic ultrasonographic examination(EUS)demonstrated an irregular,dysomogeneous echogenic lesion with central hyperechoic spots due to necrotic areas,involving the duodenal wall,probably arising from pancreatic head. An abdominal helical spiral CT with thin cuts, administrating oral and intravenous contrast medium was performed to define the mass origin. The exam revealed a solid mass, located in the second portion of the duodenum with extent to its lower flexure, most likely of neoplastic nature, without significant lymphadenopathy. This mass produced a partial duodenal obstruction, leading to a dilatation of common bile duct without enlargement of the pancreatic duct. A magnetic resonance cholangio-pancreatographic (MRCP) examination confirmed the presence of the neoplastic mass,characterized by a low intensity signal on axial T2 w images,similar to that of duodenal wall, in the second portion of the duodenum without local vascular invasion. The patient was subjected to pancreaticoduodenectomy. A pathological examination of a biopsied specimen revealed a poorly differentiated duodenal adenocarcinoma.

Discussion

An adenocarcinoma of the duodenum is a rare malignant tumor that accounts for less than 1% of all cancer of the gastrointestinal tract, but it represents 45%-65% of small bowel cancer. These tumors may develop de novo in the duodenum or may result from the malignant degeneration of preexisting adenomatous polyps, like in this report. The diagnosis is usually made with endoscopy and biopsy that allow to define the histology of the tumor. CT and MRI were shown to provide additional informations in the pre-operative assessment of these lesions.In this case,an endoscopic ultrasonographic examination was performed to detect the depth of infiltration of the duodenal wall and the locoregional extent of the tumor,but it did not give a correct diagnosis,because the duodenal mass had been mistaken for a primary pancreatic cancer.In fact,EUS is a very reliable technique in evaluating the wall layer structure of the duodenum,but it is limited by the small depth of visualization that doesn't always allow to define the origin of a large mass. CT is the method of choice for an accurate staging of small bowel neoplasm, in order to assess the locoregional extent, the presence of lymphoadenopaty, vascular invasion and distant metastatic desease.Instead , MRCP can help to characterized better the tumor through the analysis of intensity signal and is useful particularly in lesions involving biliary tract thanks to its three-dimensional reconstruction by using a maximum-intensity projection(MIP) algorithm. In fact,in this patient distal common bile duct was shaped by the duodenal lesion ,that particularly caused a dilatation of the cholechus with a normal pancreatic duct.This aspect ruled out the pancreatic origin of the tumor and confirmed diagnosis of primary duodenal adenocarcinoma.This case demonstrates CT and MRI examination have been allowed ,not only the accurate pre-operative staging of the tumor,but also the correct diagnosis,differentiating the primary duodenal adenocarcinoma from a pancreatic cancer.The authors highlight,despite the rarity of early duodenal cancer,it is important to be aware of its radiologic findings because affected individuals have a much better prognosis when the lesions are detected at an early stage with a high percentage of successfully pancreaticoduodenectomy.In this way,the radiologist plays a major rule in early diagnosis,therapeutic choice and prognosis of these patients with duodenal malignant tumors.

Differential Diagnosis List

Final Diagnosis

Primary duodenal adenocarcinoma

URL:	https://www.eurorad.org/case/4222
DOI:	10.1594/EURORAD/CASE.4222
ISSN:	1563-4086