胰腺导管内乳头状黏液性肿瘤的诊断和鉴别诊断

目的探讨胰腺导管内乳头状黏液性肿瘤的临床病理学特征及其与黏液囊性肿瘤的鉴别诊断要点。方法复习17例导管内乳头状黏液性肿瘤的临床病理学特征,与13例黏液囊性肿瘤对照;行HE染色及免疫组织化学EnVision法染色,检测肿瘤内黏液素MUC（1、2、5AC）的表达。结果17例导管内乳头状黏液性肿瘤中10例发生在男性;13例位于胰头。大体切面可观察到15例肿瘤与胰腺主导管相通。镜下可见到胰腺导管增生呈乳头状,并有上皮轻至重度不典型增生的改变。无卵巢样间质,肿瘤内交错出现萎缩或正常的胰腺腺泡和胰岛。9例主要表达MUC2,4例主要表达MUC5AC,4例伴有浸润癌者主要表达MUC1。13例黏液囊性肿瘤中11例发生于中老年女性;胰尾部10例,胰头1例,全胰腺2例;肿瘤与主导管不相通。组织学特征是含有卵巢样间质。肿瘤细胞主要表达MUC5AC,不表达MUC2,伴有浸润癌的2例,癌组织也表达MUC1。结论导管内乳头状黏液性肿瘤预后较好,患者性别、年龄、肿瘤部位、卵巢样间质、与主胰管是否相通及表达MUC2和（或）MUC1检测均可帮助诊断,并与黏液囊性肿瘤鉴别。后者主要表达MUC5AC。MUC1阳性提示侵袭性生物学行为。

Diagnosis and differential diagnosis of intraductal papillary mucinous neoplasm of pancreas

Objective To study the clinicopathologic features of intraductal papillary mucinous neoplasm (IPMN) and its distinction from mucinous cystic neoplasm of pancreas. Methods The clinical, radiologic and histologic features of 17 cases of IPMN and 13 cases of mucinous cystic neoplasm (MCN) were reviewed. Mucin profiles (MUC1, MUC2 and MUC5AC) were studied by histology (HE) and immunohistochemistry(EnVision). Results 10 of the 17 cases of IPMN were males. 13 cases of the IPMN were located in head of pancreas. Communication with the main pancreatic duct was demonstrated in 15 cases. Histologically, there were mild to severe papillary ingrowths of dysplastic epithelial cells, associated with intervening normal or atrophic pancreatic parenchyma. Ovarian-like stroma was not seen. Ancillary investigations showed that MUC2 and MUC5AC were detected in tumor cells of 9 and 4 cases respectively. The 4 cases with invasive component showed MUC1 positivity. On the other hand, 11 of the 13 cases of MCN occurred in middle-aged to elderly females and were located in the body and tail of pancreas. Ovarian-like stroma was commonly seen and there was no connection with the main pancreatic duct. All non-invasive MCN, regardless of the degree of cytologic atypia, were positive for MUC5AC (but not MUC2). In the 2 cases with invasive component, MUC1 expression was observed, as in IPMN. Conclusions The age and sex of patients, tumor location, absence of ovarian-like stroma, communication with main pancreatic duct and characteristic mucin profiles represent useful parameters in distinguishing IPMN from MCN of pancreas. The tumor cells of IPMN express mainly MUC2, while those of MCN express MUC5AC. MUC1 may also be a useful marker in demonstration of stromal invasion in these tumors.