Clear-cell syringoma. A study by conventional and electron microscopy.
The epithelial component of a syringoma is usually composed of cuboidal cells that have a moderate amount of eosinophilic cytoplasm in tissue sections stained with hematoxylin and eosin. Some syringomas have variable numbers of larger epithelial cells that have pale or clear cystoplasm. Such lesions have been called clear-cell syringomas. Examination of 18 cases by conventional microscopy revealed that their general organization is the same as ordinary syringomas but that the epithelial component constitutes a greater proportion of neoplastic volume. Histochemical studies confirmed that the clear cells contain abundant glycogen. The cells near lumina also contained a mucous substance that had a staining profile consistent with sialomucin. Examination by electron microscopy of two lesions composed entirely of clear cells revealed numerous multivesicular bodies, some in large aggregates, in periluminal cells. All cells contained numerous glycogen granules. Lesions in which there were incomplete changes in clear cells tended to have cells predominantly around the lumina. These observations suggest that the majority of clear cells result from accumulation of glycogen. The periluminal cells may be clear owing to the large number of multivesicular bodies and storage of sialomucin in them.
D000236:Adenoma / Q000473:pathology*; D000293:Adolescent; D000328:Adult; D000368:Aged; D005142:Eyelid Neoplasms / Q000473:pathology; D005153:Facial Neoplasms / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D008854:Microscopy, Electron; D008875:Middle Aged; D013544:Sweat Gland Neoplasms / Q000473:pathology*