Objective:To investigate the clinicopathological and immunohistochemical features, histogenesis and biologic behaviors of choroids plexus tumors of the cerebellopontine(CP) angle. Methods:Four cases of choroids plexus tumors of the CP angle were studied by histopathological analysis, immunohistochemical staining and electron microscopic examination. The literatures were review emphasising the diagnostic criteria, differential diagnosis and histogenesis. Results:The histopathologic features of choroid plexus tumors of the CP angle were identical to that in the ventricular system. Immunohistochemical analysis showed that S-100, vimentin and CK of the tumor cells express positive. Choroid plexus papilloma expressed GFAP. The carcinoma of choroid plexus expressed CEA as well. Conclusion:Choroid plexus tumors arising in and occupying the CP angle are rare. The final diagnosis can be made by pathologic examination. The histogenesis may be the small choroid tuft protruding from the foramen of Luschka into the CP angle.

Two cases of Paneth's cell adenoma of the stomach are reported and their morphological, histochemical, immunohistochemical, ultrastructural and immunocytochemical features are described. Both surgical specimens showed varied dysplasia with severe atrophic gastritis and intestinal metaplasia. 60%-70% of the tumor cells contained coarse eosinophilic cytoplasmic granules that are PAS positive but unstained by alcian blue at pH 2.5, and exhibited positive antiserum immunoreaction for ly-sozyme. The Paneth's nature of these granules was confirmed by electron microscopy and immunoelec-tron microscopy. In addition, some endocrine cells were detected in the neoplastic glands. The characteristics of Paneth's cell adenoma of the stomach are discussed and a close relationship between the histogenesis and intestinal metaplasia is suggested.