[Microcystic serous cystadenoma of the pancreas. Enucleation or regulated pancreatic resection?]. / Cistoadenoma sieroso microcistico del pancreas. Enucleazione o resezione pancreatica regolata?

Cystic benign tumors of the pancreas are rare lesions: they represent less than 10% of all pancreatic neoplasms. We studied two cases of microcystic adenoma, one of the less common varieties, that only in the last few years has been morphologically recognized as a distinct pathological entity. Our clinical experience--though limited--made us remark some interesting features: 1) preoperative diagnostic procedures (ultrasonography and CT) may present great interpretative difficulties: in one of the cases observed, radiographic imaging demonstrated an unresectable pancreatic tumor. On the contrary, in both cases surgical radicality has been achieved; 2) preoperative needle aspiration cytology (FNAB) does not always provide diagnostic material, as happened in both case observed; 3) the diagnosis of a benign tumor may result from surgical exploration and multiple biopsies with intraoperative frozen sections. Further and more complex histological investigations will definitively diagnose a microcystic adenoma; 4) in disagreement with some authors' results, we observed that microcystic adenoma may grow rapidly: one of our patients, after an incomplete tumor enucleation, developed a local relapse in a few months, needing a subtotal distal pancreatectomy, followed by complete recovery; 5) surgical radicality is mandatory. This result can be achieved through a simple, but complete, tumor enucleation or through a pancreatic resection; 6) our immunohistochemical and ultrastructural studies on microcystic adenoma exhibited no cells with endocrine activity, supporting the hypothesis that this tumor may originate from ductal or centroacinar cells.

[Microcystic adenoma of the pancreas. Immunohistochemical and ultrastructural study of 7 cases]. / L'adenoma microcistico del pancreas. Studio immunoistochimico e ultrastrutturale di 7 casi.

Microcystic cystadenoma of pancreas is a rare benign neoplasm with peculiar pathologic characteristics. It is more frequent in women and in elderly age. Macroscopically it is composed of a spongy, microcystic mass with a starry central fibrous core. Histologically serous cysts are lined by cuboidal or flattened epithelium without nuclear atypias and with PAS positive cytoplasms. A surgical conservative approach is the treatment of choice. Seven cases of microcystic cystoadenomas of the pancreas observed within ten years at Osp. San Carlo Borromeo-Milano and Osp. Santa Maria degli Angeli-Pordenone from 6 women and 1 man aged 54-87 years are described. The preoperative and intraoperative investigations that have been necessary for reaching its diagnosis are discussed.

Purification, cDNA cloning, and tissue distribution of bovine liver aldehyde oxidase.

Aldehyde oxidase was purified to homogeneity from bovine liver and primary structural information obtained by sequencing a series of cleavage peptides permitted the cloning of the corresponding cDNA. The cDNA is 4,630 base pairs long, and it consists of a 102-base pair 5'-untranslated region followed by a 4017-base pair coding region and a 511-base pair 3'-untranslated region. The open reading frame predicts a 1339-amino acid polypeptide with a calculated molecular weight of 147,441, which is consistent with the size of the aldehyde oxidase monomeric subunit. The aldehyde oxidase polypeptide contains consensus sequences for iron-sulfur centers and a molybdopterin binding site. The amino acid sequence deduced from the cDNA shows significant similarity with that of xanthine dehydrogenases from various sources. The primary structure of bovine aldehyde oxidase is remarkably similar (approximately 86%) to that of the translation product of a cDNA recently isolated by Wright et al. (Wright, R. M., Vaitaitis, G. M., Wilson, C. M., Repine, T. B., Terada, L. S., and Repine, J. E. (1993) Proc. Natl. Acad. Sci. U.S.A. 90, 10690-10694) and reported to represent human xanthine dehydrogenase. With the help of a monospecific antibody raised against the purified protein and the isolated cDNA, the tissue distribution of the bovine aldehyde oxidase protein and corresponding mRNA was determined. Aldehyde oxidase is expressed at high levels in liver, lung, and spleen, and, at a much lower level, in many other organs.