Adenocarcinoma with intraductal papillary mucinous neoplasm arising in jejunal heterotopic pancreas

Abstract

A 74-year-old man suffered from jejunal perforation and adhesion to sigmoid colon due to adenocarcinoma associated with intraductal papillary mucinous neoplasm (IPMN) arising in a jejunal heterotopic pancreas. The jejunal lesion showed direct extension to the sigmoid colon, which was mistaken as sigmoid colon cancer by surgeons. Malignant transformation is a rare complication of a heterotopic pancreas. About half of malignancies in reported cases were ductal adenocarcinoma arising in the stomach, and the jejunal location is extremely rare. Furthermore, IPMN is also uncommon finding in a heterotopic pancreas.

Keywords: Adenocarcinoma; Heterotopia; Jejunum; Pancreas.

Fig. 1

The jejunal wall shows areas of intraductal papillary mucinous neoplasm, invasive adenocarcinoma and heterotopic pancreas (arrow).

Fig. 2

The heterotopic pancreas in jejunum demonstrates aggregates of ducts and acini.

Fig. 3

Grades of pancreatic intraepithelial neoplasia (PanIN). (A) A duct involved by PanIN2 shows pseudostratification of nuclei with mild to moderate cytologic abnormalities. (B) In PanIN3, budding of cellular tufts into the duct lumen and moderate to severe nuclear atypia are noted.

Fig. 4

A cystically dilated duct is containing intraluminal papillae. The papillae are lined by tall columnar cells with abundant apical cytoplasmic mucin and basally oriented nuclei with mild to moderate dysplasia, consistent with intraductal papillary mucinous neoplasm.

Fig. 5

(A) A transitional area from high grade pancreatic intraepithelial neoplasia to adenocarcinoma is identified. (B) A transitional area from intraductal papillary mucinous neoplasm to adenocarcinoma is present.

Fig. 6

The sigmoid colon shows transmural invasion by adenocarcinoma.