Coexisting Mucinous Cystic Neoplasm of the Pancreas and Type 1 Autoimmune Pancreatitis
- Author:
Mee Jeong KIM
1
;
Tae Jun SONG
;
Hyoung Jung KIM
;
Song Cheol KIM
;
Myung Hwan KIM
;
Seung Mo HONG
Author Information
- Publication Type:Case Report
- Keywords: Pancreas; Mucinous cystic neoplasm; Autoimmune pancreatitis
- MeSH: Epithelial Cells; Female; Fibrosis; Follow-Up Studies; Humans; Mucins; Pancreas; Pancreatectomy; Pancreatitis; Phlebitis; Plasma Cells; Receptors, Progesterone; Tail
- From:Journal of Pathology and Translational Medicine 2019;53(2):125-128
- CountryRepublic of Korea
- Language:English
- Abstract: Type 1 autoimmune pancreatitis (AIP1) is an IgG4-related systemic disease that mimics tumors. We report a rare case of AIP1 accompanied by mucinous cystic neoplasm (MCN). A pancreatic lesion was incidentally detected in a woman in her 60s. After 6 years of follow-up, the lesion abruptly increased in size. Computed tomography showed a 3.5 cm unilocular cyst in the tail of the pancreas and distal pancreatectomy was performed. On microscopic examination, the cyst was lined by mucinous and non-mucinous epithelial cells with mild cytologic atypia. The surrounding stroma comprised ovarian-type spindle cells with progesterone receptor positivity. The pericystic pancreas exhibited multifocal lymphoid follicles, lymphoplasmacytic infiltrations, obliterative phlebitis, and storiform fibrosis. IgG4-positive plasma cell infiltration (215 cells high-power field) and the IgG4/IgG ratio (57%) were increased. Cases of MCN coexisting with AIP1 are extremely rare; only two such cases have been reported in the English-language literature. This third case featured low-grade MCN with AIP1.
