Selective fluorescence study of salivary pleomorphic adenoma stroma with confocal laser microscope in stained slices with Hematoxylin / Eosine yellow

Abstract

Introduction: The pleomorphic adenoma (PA) is a benign salivary gland tumor. It has ductal cells,myoepitheliocytes and a stroma with hyalinised, myxoid and chondroid metaplasia zones. On the other hand, the H/ E gives an integral view of the tissue structure. Hematoxylin acts as a basic dye that stains violet. The eosin is an artificial acid dye that stains pink eosinophilic structures. The Eosina Y is strongly fluorescent, which allows to identify with the confocal laser microscope eosinophilic structures that are sometimes little visible to the photonic microscope. Objective: The PA chondroid stroma was analyzed with photonic and confocal scanning laser microscopes to demonstrate the value of the fluorescence emitted by Eosin Y in its structural description. Material & Methods: The histological examination of 10 PA parotid stained with H/E Y was performed. The images of the histological preparations were obtained by means of a photonic optical microscope and a FV1000 Olympus spectral confocal laser microscope, configured for the acquisition of orange / red fluorescence of the Eosin obtained between 555 to 655 nm. The eosin was excited at 543 nm using the He-Ne gas laser. Results: Photonic microscopy: The chondroid tumor areas presented a variable extension predominantly in only 4 cases. Histologically, these areas looked like immature hyaline cartilage, a chondroid type with an amorphous-like basophilic extracellular matrix and lacunae with round or oval chondroidocytes. * Scanning confocal laser microscopy: structures with strong red fluorescence were observed swollen in the extracellular matrix, the pericellular capsule of the chondroidocytes and the collagen of the territorial and inter-territorial matrices. Conclusions: The confocal laser scanning microscope allows visualizing structures in PA slides stained with H/E Y not visible to the clear field. We highlight the usefulness of H/E Y in histopathology both in photonic microscopy and confocal laser scanning microscopy.