glycogen and Cystadenoma--Serous

Pancreatic cysts are common, but cystic tumors are uncommon. We report a rare case of serous cystadenoma of the pancreas synchronous with ampullary adenocarcinoma which supports a common etiopathogeny of these tumors. We discuss the differential diagnosis with mucinous cystadenoma which is potentially malignant and recall the microscopic and radiologic features.

Topics: Adenocarcinoma; Aged; Cystadenoma, Serous; Diagnosis, Differential; Female; Glycogen; Humans; Neoplasms, Second Primary; Pancreatic Neoplasms

Serous microcystic adenoma of the pancreas, also known as microcystic adenoma, glycogen-rich cystadenoma or serous cystadenoma, is an uncommon benign tumor. We have studied 11 cases involving eight women and three men. The average age at diagnosis was 61.7 years. Four tumors were discovered incidentally. Tumors varied from 1.2 to 20 cm in maximum diameter and all were multicystic. Within the pancreas, three were located in the pancreas head, one involved the head and body, one was located in the body, five were in the tail, and one occupied the whole pancreas. Central stellate scar was seen in five (45%) cases. Histologically, all tumors were composed of microglandular cysts lined by clear epithelial cells rich in glycogen, which were separated by fibrocollagenous stroma. The expression of keratin in clear epithelial cells resembled that in ductal and/or centroacinar cells, but not acinar cells. alpha-Smooth muscle actin (SMA)-positive myoepithelial cells and stromal amyloid deposits were not detected. Ultrastructurally, fibrocollagenous stroma was composed of alpha-SMA-positive myofibroblasts and endothelial cells embedded in thick collagen bundles. Regardless of female propensity, estrogen and progesterone receptors were not detected. Therefore, female predominance in this tumor remains to be elucidated.

Topics: Aged; Biomarkers, Tumor; Cystadenoma, Serous; Female; Glycogen; Humans; Immunohistochemistry; Male; Middle Aged; Pancreatic Neoplasms; Periodic Acid-Schiff Reaction; Sex Distribution

Serous cystic tumours of the pancreas are uncommon and are usually classified as microcystic adenomas (MCA). As new types of serous cystic tumours of this organ have been reported we reviewed a series of 14 lesions and from macroscopic findings two groups were distinguished: ten tumours revealed the features of MCA, while four were clearly distinct from MCA. Grossly, the latter tumours showed only few cysts which were irregularly assembled in fibrous stroma. On the cut surface, there was neither a central stellate scar nor a circumscribed tumour border, features characterizing MCA. Microscopically, the cysts were lined by cuboidal, non-mucin-producing cells. Immunocytochemical staining for cytokeratins 7, 8, 18 and 19 revealed a ductal phenotype. All non-MCA were found in the head of the pancreas and three of them occurred in men. There were no tumour recurrences or signs or malignant transformation after resection (mean follow-up, 2.9 years). These results suggest that there are serous cystic tumours distinct from MCA which may represent another variant of the category of serous cystic adenomas of the pancreas. We propose the term serous oligocystic and ill-demarcated adenoma (SOIA) for these tumours. It is possible that the recently described macrocystic sybtype of serous cystadenoma and SOIA and variants of the same tumour.

Topics: Adenoma; Aged; Aged, 80 and over; Amylases; Cystadenoma, Serous; Cytoplasm; Female; Glycogen; Humans; Immunohistochemistry; Male; Middle Aged; Pancreatic Neoplasms; Periodic Acid-Schiff Reaction