title: Scanning electron microscopy of dimethylbenzanthracene (DMBA)-treated hamster cheek pouch.
abstract: The aim of the present study was to describe changes which could be regarded as a result of neoplastic rather than inflammatory processes. Fifty-five weeks after 6 weeks of DMBA application to the cheek pouches of 5 male hamsters there were 4 types of lesion: larger ulcerated sessile; smaller non-ulcerated sessile; non-ulcerated pedunculated; conical projections. These and the rest of the pouches were examined by scanning electron and light microscopy. The interlesional mucosa, non-ulcerated sessile lesions and conical projections were covered by flat polygonal cells with either a honeycomb surface pattern of interconnecting microridges, or microridges arranged into more parallel lines. Cell imprints and boundaries were formed by linear ridges, grooves or both. Pedunculated lesions had flat smooth-surfaced cells and cells with a honeycomb surface pattern. None of these lesions were carcinomas by light microscopy but the ulcerated sessile lesions were. The appearance of the cells on the ulcerated lesions varied: flat, with a variable number of short microvilli that were often knob-like, isolated short microridges, or both; plump, giving a cobblestone appearance with surfaces that were smooth, covered by microvilli, short microridges or both. Such appearances have been described as characteristic for dysplastic and malignant stratified squamous epithelium in a number of sites. Further study of both experimental and naturally occurring mucosal disease is needed to validate this.
authors.affiliation: Department of Oral Biology & Oral Pathology, University of Otago, Dunedin, New Zealand.
authors.forename: M D
authors.initials: MD
authors.lastname: McMillan
authors.forename: A C
authors.initials: AC
authors.lastname: Smillie
mesh_terms: D015127:9,10-Dimethyl-1,2-benzanthracene / Q000009:adverse effects*; D000818:Animals; D002273:Carcinogens / Q000009:adverse effects*; D002277:Carcinoma / Q000139:chemically induced / Q000473:pathology; D002610:Cheek; D003094:Collagen; D003238:Connective Tissue / Q000187:drug effects / Q000473:pathology; D006224:Cricetinae; D004848:Epithelium / Q000187:drug effects / Q000473:pathology; D005110:Extracellular Space / Q000187:drug effects; D008214:Lymphocytes / Q000187:drug effects / Q000473:pathology; D008297:Male; D008855:Microscopy, Electron, Scanning; D008871:Microvilli / Q000187:drug effects / Q000648:ultrastructure; D009061:Mouth Mucosa / Q000187:drug effects* / Q000648:ultrastructure; D009062:Mouth Neoplasms / Q000139:chemically induced* / Q000473:pathology; D014456:Ulcer / Q000139:chemically induced / Q000473:pathology
chemical_list: D002273:Carcinogens; D015127:9,10-Dimethyl-1,2-benzanthracene; D003094:Collagen