Recently, endoscopic ultrasonography-guided fine needle aspiration (EUS-FNA) has been applied for diagnosis of gastrointestinal submucosal tumors. There have been no definite criteria, however, for the adequate cytological diagnosis of gastrointestinal stromal tumor (GIST) in practice. To facilitate this a novel method is proposed that combines cytology and histology. For 49 cases of submucosal tumor of gastrointestinal tract, EUS-FNA was performed. The aspirated materials were processed for cytology and histology. Both cytological and histological findings were examined on immunocytochemical and immunohistochemical staining of c-kit. Of 49 cases, 40 (81.6%) proved adequate for cytological and/or histological examination. On cytology, cluster types were classified into type A (piled clusters with high cellularity showing a fascicular pattern), type B (thin layered clusters with high cellularity showing a fascicular pattern), and type C (mono-layered clusters or scattered cells). Types A and B were strongly associated with histological diagnosis of GIST. Type C clusters needed confirmation on c-kit positivity and histology. Thus, the combined cytology with newly defined features, and classification and histological diagnostic method for EUS-FNA materials can contribute to improved routine diagnosis for GIST.

Evidence has been provided in ulcerative colitis (UC) that early genomic instability of both epithelial and stromal cells is important for colorectal tumorigenesis, as well as remodeling and morphological alterations of mucosal crypts. To clarify roles of stromal cells in tumor development in UC, the present study focused on heterogeneous phenotypes of subepithelial myofibroblasts and interstitial cells, in association with mucosal remodeling. To clarify the relationship of alterations to tumorigenesis, mucosa of resected rectae from patients with UC (n= 49) and sporadic cancer (n= 10) were analyzed on immunohistochemistry and also on immunoelectron microscopy. Heterogeneous phenotypes of neural cell adhesion molecule (NCAM)+ and/or alpha-smooth muscle actin (alpha-SMA)+ subepithelial myofibroblasts and interstitial cells were demonstrated, corresponding to colonic stellate cells. Decrease of NCAM+ subepithelial myofibroblasts and interstitial cells, and increase of alpha-SMA+ interstitial cells were significant in UC with neoplasia as compared to without neoplasia. alpha-SMA+ muscularis mucosae was significantly more thickened in tumor cases. Deposits of Masson's trichrome+ and type III and I collagen in the muscularis mucosae and lamina propria appeared to increase in relation to the numbers of alpha-SMA+ interstitial cells. Mucosal remodeling with alterations of NCAM+ or alpha-SMA+ subepithelial and interstitial cells may play a critical role in UC-associated tumorigenesis.

Multilobated B-cell lymphoma-Ascites cytology-Immunoglobulin heavy chain gene rearrangement-Electron microscopy A case of a multilobated B-cell lymphoma, probably derived from a parapancreatic lymph node-Cytologic and electron microscopic features, and gene analysis

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