title: [A case of invasive ductal carcinoma of the pancreas originating from an intraductal papillary mucinous tumor that was initially misdiagnosed as a mucinous cystic tumor].
abstract: A 57-year-old woman was discovered to have a cystic tumor, 8 cm in diameter, at the pancreas tail, during routine screening with ultrasonography. The patient did not complain of tenderness, and no abdominal mass was palpable at physical examination. Enhanced computed tomography(CT) revealed that the tumor had mural nodules in the cyst wall, and we suspected it to be a malignant tumor that had occurred in the mucinous cystic neoplasm(MCN). Therefore, surgical resection was attempted, upon which the tumor was found to be hard and the surrounding tissue adhered widely to the stomach. We separated it carefully from the stomach and then performed a distal pancreatectomy. The cut surface revealed that the posterior wall of the cystic tumor was partly thickened, and microscopic examination revealed it to be invasive ductal carcinoma. No ovarian-like stroma was involved and some degree of dysplasia(PanIN 1-3) was found in the neighboring tissues. Therefore, we re-diagnosed it to be invasive ductal carcinoma of the pancreas derived from intraductal papillary mucinous tumor(IPMT), not from MCN. The patient received adjuvant chemotherapy, although 5 months later multiple lung metastases had appeared. The international consensus guidelines for management of IPMN and MCN of the pancreas suggest that they can usually be distinguished preoperatively, if there is a complete understanding of their clinical and imaging features. However, we sometimes find it difficult to distinguish the 2, because some IPMN or MCN cases have shared preoperative features. Herein, we report the case of invasive ductal carcinoma of the pancreas derived from IPMT that was originally misdiagnosed as a MCN.
authors.affiliation: Dept. of Surgery, Yao Municipal Hospital, Japan.
authors.forename: Shigekazu
authors.initials: S
authors.lastname: Yokoyama
authors.forename: Yo
authors.initials: Y
authors.lastname: Sasaki
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Hashimoto
authors.forename: Mitsunobu
authors.initials: M
authors.lastname: Takeda
authors.forename: Reishi
authors.initials: R
authors.lastname: Toshiyama
authors.forename: Shuichi
authors.initials: S
authors.lastname: Fukuda
authors.forename: Atsushi
authors.initials: A
authors.lastname: Naito
authors.forename: Shinji
authors.initials: S
authors.lastname: Matsumoto
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Tokuoka
authors.forename: Yoshihito
authors.initials: Y
authors.lastname: Ide
authors.forename: Jin
authors.initials: J
authors.lastname: Matsuyama
authors.forename: Takashi
authors.initials: T
authors.lastname: Morimoto
authors.forename: Yukio
authors.initials: Y
authors.lastname: Fukushima
authors.forename: Takashi
authors.initials: T
authors.lastname: Nomura
authors.forename: Ken
authors.initials: K
authors.lastname: Kodama
authors.forename: Ikue
authors.initials: I
authors.lastname: Shiba
authors.forename: Masashi
authors.initials: M
authors.lastname: Takeda
mesh_terms: D002288:Adenocarcinoma, Mucinous / Q000175:diagnosis*; D021441:Carcinoma, Pancreatic Ductal / Q000175:diagnosis*; D002291:Carcinoma, Papillary / Q000175:diagnosis*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D010190:Pancreatic Neoplasms / Q000175:diagnosis*