title: A case of mucinous cystic neoplasm of the pancreas misdiagnosed as a pancreatic pseudocyst at the initial exam and resected after a 2-year follow-up.
abstract: A 44-year-old woman was referred to our hospital because of a cystic lesion in the pancreatic body that was found by computed tomography (CT) as a result of a screening for impaired liver function after the patient presented with a high fever in 2011. Trans-abdominal ultrasonography (US) revealed a 33-mm unilocular cyst within the pancreatic body and a 5-mm hypoechoic mass in the pancreatic neck. Contrast-enhanced CT showed a slight enhancement around the cyst and a mild dilation of the main pancreatic duct, but neither septum nor nodule was detected inside. Contrast-enhanced endoscopic ultrasonography (CE-EUS) revealed a hyperechoic elevated lesion inside the cystic lesion without enhancement in the pancreatic body; CE-EUS also revealed a 5-mm homogeneous hypoechoic mass with a remarkable enhancement in the pancreatic neck with the use of Sonazoid(®) as a contrast medium. These lesions were diagnosed as a pancreatic pseudocyst and a neuroendocrine tumor (NET), respectively, and were followed up with periodic examinations. The cystic lesion showed contraction 6 months after the initial exam. However, US revealed an enlargement of the cystic lesion to 40 mm in diameter 2 years after the initial exam, and EUS showed irregular thickening of the wall with a cyst-in-cyst appearance. The diagnoses of a mucinous cystic neoplasm (MCN) and a concomitant small NET were made after a distal pancreatectomy. We herein report a rare case of MCN that showed various morphological changes over 2 years of observation.
authors.affiliation: Department of Gastroenterology, Japanese Red Cross Nagoya Daiichi Hospital, 3-35 Michishita-cho, Nakamura-ku, Nagoya, 453-8511, Japan. takuya2602@gmail.com.
authors.forename: Takuya
authors.initials: T
authors.lastname: Ishikawa
authors.affiliation: Department of Gastroenterology, Japanese Red Cross Nagoya Daiichi Hospital, 3-35 Michishita-cho, Nakamura-ku, Nagoya, 453-8511, Japan.
authors.forename: Jun-Ichi
authors.initials: J
authors.lastname: Haruta
authors.affiliation: Department of Gastroenterology, Japanese Red Cross Nagoya Daiichi Hospital, 3-35 Michishita-cho, Nakamura-ku, Nagoya, 453-8511, Japan.
authors.forename: Takeo
authors.initials: T
authors.lastname: Yamaguchi
authors.affiliation: Department of Gastroenterology, Japanese Red Cross Nagoya Daiichi Hospital, 3-35 Michishita-cho, Nakamura-ku, Nagoya, 453-8511, Japan.
authors.forename: Masao
authors.initials: M
authors.lastname: Doisaki
authors.affiliation: Department of Gastroenterology, Japanese Red Cross Nagoya Daiichi Hospital, 3-35 Michishita-cho, Nakamura-ku, Nagoya, 453-8511, Japan.
authors.forename: Tsuyoki
authors.initials: T
authors.lastname: Yama
authors.affiliation: Department of Gastroenterology, Japanese Red Cross Nagoya Daiichi Hospital, 3-35 Michishita-cho, Nakamura-ku, Nagoya, 453-8511, Japan.
authors.forename: Kentarou
authors.initials: K
authors.lastname: Murate
authors.affiliation: Department of Gastroenterology, Japanese Red Cross Nagoya Daiichi Hospital, 3-35 Michishita-cho, Nakamura-ku, Nagoya, 453-8511, Japan.
authors.forename: Shun
authors.initials: S
authors.lastname: Hattori
authors.affiliation: Department of Gastroenterology, Japanese Red Cross Nagoya Daiichi Hospital, 3-35 Michishita-cho, Nakamura-ku, Nagoya, 453-8511, Japan.
authors.forename: Fumihiro
authors.initials: F
authors.lastname: Hayakawa
authors.affiliation: Department of Gastroenterology, Japanese Red Cross Nagoya Daiichi Hospital, 3-35 Michishita-cho, Nakamura-ku, Nagoya, 453-8511, Japan.
authors.forename: Kenta
authors.initials: K
authors.lastname: Yamada
authors.affiliation: Department of Gastroenterology, Japanese Red Cross Nagoya Daiichi Hospital, 3-35 Michishita-cho, Nakamura-ku, Nagoya, 453-8511, Japan.
authors.forename: Jun
authors.initials: J
authors.lastname: Yashika
mesh_terms: D000328:Adult; D049448:Cholangiopancreatography, Magnetic Resonance; D003287:Contrast Media; D018291:Cystadenoma, Mucinous / Q000150:complications / Q000175:diagnosis* / Q000601:surgery; D003937:Diagnosis, Differential; D003951:Diagnostic Errors; D019160:Endosonography; D005260:Female; D005290:Ferric Compounds; D005500:Follow-Up Studies; D006801:Humans; D007501:Iron; D018358:Neuroendocrine Tumors / Q000150:complications / Q000175:diagnosis* / Q000601:surgery; D010087:Oxides; D010179:Pancreas / Q000000981:diagnostic imaging / Q000601:surgery*; D010190:Pancreatic Neoplasms / Q000150:complications / Q000175:diagnosis* / Q000601:surgery*; D010192:Pancreatic Pseudocyst / Q000175:diagnosis* / Q000000981:diagnostic imaging; D014057:Tomography, X-Ray Computed
chemical_list: D003287:Contrast Media; D005290:Ferric Compounds; D010087:Oxides; C069727:Sonazoid; D007501:Iron
keywords: Mucinous cystic neoplasm; Pancreatic neuroendocrine tumor; Pseudocyst