Diagnostic challenge: intraductal neoplasms of the pancreatobiliary system.
To help pathologists avoid misdiagnosis of intraductal neoplasms arising from the pancreatobiliary system, we report two cases that illustrate diagnostic pitfalls. The first is of a 66-year-old man who complained of appetite loss. An early examination led to a diagnosis of intraductal papillary mucinous neoplasm. Macroscopically, a multilocular cyst without visible mucin was identified. Histologically, the compartments consisted of complex fusion of tubular glands surrounded by dilated pancreatic duct. The neoplasm resembled an acinar cell cystadenocarcinoma. However, the neoplastic cells were negative for trypsin. Thus, the final histopathologic diagnosis was an unusual cystic variant of intraductal tubulopapillary neoplasm (ITPN) of the pancreas. The second case is of a 71-year-old man who complained of right upper quadrant pain. Although bile duct stone was suspected, a polypoid nodule was extracted. Histologically, the nodule was composed of tubular glands, with some complex fusion and focal dysplasia, consistent with carcinoma. In addition, lack of MUC-5AC expression led to an initial impression of ITPN of the bile duct. However, the neoplasm showed dysplastic cells based on the columnar cells resembling pyloric glands, indicating the sequential progression. Thus, the final histopathological diagnosis was intraductal papillary neoplasm of the bile duct with high-grade intraepithelial neoplasia. Because phenotypic variants of intraductal neoplasms of the pancreatobiliary system exist, ITPN and ITPN-mimicking tumor must be carefully differentiated from other intraductal neoplasms.
Department of Diagnostic Pathology, Showa University Fujigaoka Hospital, Yokohama, Japan; Department of Diagnostic Pathology, Tokai University Hachioji Hospital, Tokyo, Japan. takumatajiri1003@yahoo.co.jp
Takuma
T
Tajiri
Genshu
G
Tate
Koshi
K
Matsumoto
Hiroki
H
Hoshino
Taro
T
Iwamura
Yuzo
Y
Kodaira
Ken
K
Takahashi
Nobuyuki
N
Ohike
Toshiaki
T
Kunimura
Toshiyuki
T
Mitsuya
Toshio
T
Morohoshi
D000230:Adenocarcinoma / Q000175:diagnosis* / Q000378:metabolism / Q000556:secondary; D000231:Adenocarcinoma, Papillary / Q000175:diagnosis* / Q000378:metabolism / Q000556:secondary; D000368:Aged; D014670:Ampulla of Vater / Q000473:pathology; D014408:Biomarkers, Tumor / Q000378:metabolism; D021441:Carcinoma, Pancreatic Ductal / Q000175:diagnosis* / Q000378:metabolism / Q000556:secondary; D003138:Common Bile Duct Neoplasms / Q000175:diagnosis* / Q000378:metabolism; D003937:Diagnosis, Differential; D017809:Fatal Outcome; D006801:Humans; D008297:Male; D010190:Pancreatic Neoplasms / Q000175:diagnosis* / Q000378:metabolism; D016577:Pancreaticoduodenectomy; D012074:Remission Induction
D014408:Biomarkers, Tumor