Specific demonstration of actin filaments in salivary gland tumors using immunohistochemistry

Neoplastic and non-neoplastic salivary gland tumors represented by pleomorphicadenoma and chronic sclerosing sialadenitis were selected for theirsimilarities to the normal structural elements of salivary glands, i.e. thepresence of developed duct-like pattern. The tissues were investigated bymeans of immunocytochemistry using antibodies against the filaments of actinin paraffin-embedded material. Actin was demonstrated in tumor cells in a waycorrelated to the topographic distribution of actin-rich cells, i.e. themyoepithelial cells. Also, the identification of such type of cells providesmore information about the proliferating nature of these myoepithelial cellsand its role in the histogenesis of salivary gland tumors

histogenesis of mucoepidermoid carcinoma: histological and ultrastructural study

Seven cases of mucoepidermoid carcinoma of minor salivary gl and s, located in the palate [five cases] and lip [two cases] were encountered in the present study. By light microscopy, three cell types [mucous, squamoid and intermediate] were observed. Ultrastructural examination of four of these cases was used to reveal the type of cellular differentiation. Mainly, biphasic patterns were detected [luminal and myoepithelial cells with varying degrees of differentiation]. Based on the present findings and its correlation with histogenetic aspect, acinar intercalated duct region can be stressed as an origin for the development of mucoepidermoid carcinoma in as much as most of salivary gl and tumors originate

presence of melanocytes in the lining epithelium of maxillary sinus mucosa

Dendritic cells containing melanin pigment have been demonstrated with silver impregnation in the epithelial lining of the maxillary sinus in seven cases. An extensive review of literature has shown that melanocytes are found in some unusual locations, but previous finding of their existence in the epithelial lining of the maxillary sinus has not been reported. The literature is reviewed, and the pathologic significance of this observation in relation to the histogenesis of melanomas of the paranasal sinuses with special emphasis to the maxillary sinus is discussed

Melanoacanthomatous hyperplasia of the oral cavity: histological and histochemical study

Melanoacanthomatous hyperplasia of the oral cavity is a rare reactive phenomenon analogous histologically to the skin melanoacanthoma. A few cases were previously reported in the literature under the name "oral melanoacanthoma". This study comprised the largest series and the first to be found in Asians. Fourteen cases were detected among 27 unclassified melanotic lesions, in which a definite history of trauma was documented in five cases. Histologically, bicellular proliferative reaction of dendritic melanocytes and squamous cell proliferation, which along with evidence of inflammation in the underlying lamina propria may characterize the lesion as a part of a spectrum of reactive process rather than neoplasia

Clear cell variants of salivary gland tumors: histochemical and ultrastructural study

Eleven cases identified as primary clear cell tumors of salivary gland were studied to determine the morphologic, and ultrastructural parameters of this group. These tumors were divided into two variants;the bimorphic variant composed of well defined tubules of cuboidal cells together with clear cells, while the monomorphic variant composed of pure nests or sheets of clear cells. Ultrastructurally, the bimorphic variant exhibited differentiation towards epithelial and myoepithelial directions. On the other hand, the monomorphic variant was composed of undifferentiated cells. Despite the fact that both variants contain clear cells, they are considered to be distinctive entities