Distinct patterns of peritumoral histological findings in subtypes of intraductal papillary mucinous neoplasms of the pancreas.
Intraductal papillary mucinous neoplasms (IPMNs) of the pancreas are primary pancreatic neoplasms that can act as precursors to invasive adenocarcinoma of the pancreas. The peritumoral stroma has been increasingly recognized to play an important role in many types of tumors. Therefore, to investigate the clinicopathological significance of the peritumoral stroma in IPMNs, we examined the histological features of the peritumoral stroma in each subtype and histological grade of IPMNs. Eighty-two patients with IPMN, who underwent surgical resection, were reviewed clinicopathologically. Intraductal papillary mucinous neoplasms (86 lesions in total) were histologically subclassified into gastric (n = 51), intestinal (n = 22), pancreatobiliary (n = 11), and oncocytic (n = 2) subtypes. Peritumoral histological features between the gastric and intestinal subtypes were evaluated by each histological grade. The results showed that subepithelial edema and inflammatory cell infiltration were more commonly observed in the gastric subtype (74% and 79%, respectively) than in the intestinal subtype (12% and 25%, respectively) of low-grade IPMNs. On the other hand, mucus lakes were more commonly observed in the intestinal subtype (100%) than in the gastric subtype (0%) of high-grade IPMNs. In addition, pancreatobiliary subtype IPMNs tended to exhibit acute inflammation such as neutrophil predominance. This study showed that peritumoral histological features differed among subtypes of IPMNs from low-grade tumors. These differences suggest the possibility that each subtype of IPMNs has a distinct mechanism from an early stage of tumor progression, which is reflected in the properties of the peritumoral stroma.
Department of Diagnostic Pathology, Jichi Medical University Hospital, Tochigi 329-0498, Japan; Division of Gastroenterology and Hepatology, Department of Internal Medicine, Toho University Ohashi Medical Center, Tokyo 153-8515, Japan.
Michihiro
M
Saito
Department of Diagnostic Pathology, Jichi Medical University Hospital, Tochigi 329-0498, Japan.
Hiroki
H
Imada
Department of Diagnostic Pathology, Jichi Medical University Hospital, Tochigi 329-0498, Japan.
Tsukasa
T
Suzuki
Department of Surgery, Jichi Medical University Hospital, Tochigi 329-0498, Japan.
Naohiro
N
Sata
Department of Surgery, Jichi Medical University Hospital, Tochigi 329-0498, Japan.
Yoshikazu
Y
Yasuda
Division of Gastroenterology and Hepatology, Department of Internal Medicine, Toho University Ohashi Medical Center, Tokyo 153-8515, Japan.
Iruru
I
Maetani
Department of Diagnostic Pathology, Jichi Medical University Hospital, Tochigi 329-0498, Japan. Electronic address: nfukushima@jichi.ac.jp.
Noriyoshi
N
Fukushima
D002288:Adenocarcinoma, Mucinous / Q000145:classification / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D000231:Adenocarcinoma, Papillary / Q000145:classification / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D000368:Aged; D014408:Biomarkers, Tumor / Q000378:metabolism; D021441:Carcinoma, Pancreatic Ductal / Q000145:classification / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D010190:Pancreatic Neoplasms / Q000145:classification / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D012189:Retrospective Studies
D014408:Biomarkers, Tumor
Edema; Gastric subtype; Inflammatory cell; Intestinal subtype; Intraductal papillary mucinous neoplasm; Stroma