Fig. 2

Macroscopic and microscopic pathology (hematoxylin and eosin stain) of the surgical specimen. Macroscopically, an invasive tumor with a diameter of 15 mm (a, b, white arrow) and cystic lesions (b, white arrowheads) were observed. There was an invasive tumor with a diameter of 15 mm and cystic lesions around the tumor (c; loupe magnification, ×4). The solid tumor was proliferating with irregular small and medium-sized glandular cavities with interstitial fibrosis (d; original magnification, ×40). There were partially invasive micropapillary patterns, and differentiation into squamous cell carcinoma was noted (e; original magnification, ×200). The columnar epithelium of intraductal papillary mucinous neoplasm cysts observed around the solid tumor had a papillary appearance (f; original magnification, ×20)