title: Crystalloid formation in gastrointestinal schwannoma.
abstract: We found intracytoplasmic crystalloids in two of six cases (33.3%) of gastrointestinal (GI) schwannomas. The crystalloid inclusions were periodic acid-Schiff (PAS) positive with diastase-resistance and stained blue with Masson's trichrome. They were needle-shaped and about 1 to 15 microm in length at microscopic levels. They had varying electron density revealed by electron microscopy and some of them showed distinct lattice structure with periodicity of about 9 nm. Survey of soft tissue schwannomas (n = 20) and S-100-negative GI stromal tumors (n = 41) did not detect such crystalloids. Although the origin and differentiation of GI stromal tumors (GISTs) have been a source of controversy, these intracytoplasmic crystalloids may be a marker for Schwann cell differentiation in some GIST.
authors.affiliation: Department of Pathology, Hirosaki University School of Medicine, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Yagihashi
authors.forename: M
authors.initials: M
authors.lastname: Kaimori
authors.forename: Y
authors.initials: Y
authors.lastname: Katayama
authors.forename: S
authors.initials: S
authors.lastname: Yagihashi
mesh_terms: D000328:Adult; D000368:Aged; D003593:Cytoplasm / Q000737:chemistry / Q000648:ultrastructure; D005260:Female; D005770:Gastrointestinal Neoplasms / Q000737:chemistry / Q000648:ultrastructure*; D006801:Humans; D007150:Immunohistochemistry; D002479:Inclusion Bodies / Q000648:ultrastructure*; D008297:Male; D008854:Microscopy, Electron; D008875:Middle Aged; D009442:Neurilemmoma / Q000737:chemistry / Q000648:ultrastructure*; D009418:S100 Proteins / Q000032:analysis
chemical_list: D009418:S100 Proteins