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This electronmicroscope study of the histogenesis of mucoepidermoid carcinoma is based on 15 cases from the major and minor salivary glands. Six major cell types were identified: undifferentiated (cuboid) stem cells, intermediate (columnar) ceils, serous/mucoid secretory cells, mucus-producing goblet ceils. squamous/epidermoid cells and myoepithelium It is proposed that undifferentiated stein ceils serve as pluripotential reserves which give rise to the various cell types seen in mucoepidermoid carcinoma. Reserve cells in the acinar-intercalated duct components of the salivary glands appeared to give rise to the serous/mucoid and myoepithelial cell populations of mucoepidermoid carcinoma. Reserve cells in the proximal ducts system (intra/extralobular striated ducts and excretory ducts) differentiated into myoepithelium. intermediate (columnar) cells, squamous/epidermoid and mucus-producing goblet cell lines, It is proposed that neoplastic reserve cells give rise to different tumor types in the salivary glands. These types result from varying admixtures and arrangements of tumor cells at different stages of their structural and functional cytodifferentiation from reserve cells. It is further proposed that neoplastic reserve cells differentiate along similar cell lines as the embryonic "stem cells" in the development of normal salivary glands. [ABSTRACT FROM AUTHOR]

Cytohormonal evaluation has become an accurate procedure for the assessment of estrogenic effect on the vaginal and buccal mucosa. Both show a cyclical variation in the maturation index (an "estrogenic value" based on epithelial maturation). Conjunctival smears were taken from the temporal conjunctiva of 11 premenopausal and 7 postmenopausal females on a near-daily basis. No females had evidence of ocular surface disease, including keratoconjunctivitis sicca. After fixation and Papanicolaou staining, maturation indices for each specimen based on the differential morphology were red in a single blind fashion by a Papanicolaou cytologist. Cyclical variations paralleling the menstrual cycle in eight of nine premenopausal women were noted with maturation index values ranging from 30 (low estrogen effect) to 82 (high estrogen effect), peaking on day 11 or 21 of the menstrual cycle. No cyclical change was found in postmenopausal smears and smears of subjects with endocrine abnormalities. Maturation index values ranged from 30 to 38. Conjunctiva appears to be an estrogen-sensitive epithelium.

This study describes the light microscopic, histochemical and electron-microscopic findings of 10 acinic cell carcinomas from the major and minor salivary glands. Ultrastructurally, four cell types were identified: secretory acinar cells, intercalated duct-like cells, pluripotential reserve/stem cells and myoepithelial cells. This cellular composition suggests that the tumours are derived from neoplastic proliferation, cytodifferentiation and functional maturation of pluripotential reserve/stem cells which normally reside at the acinar-intercalated duct junctions and/or in the intercalated ducts proper of adult salivary glands. This study further supports the concept that different salivary gland tumours recapitulate various developmental stages in the normal embryogenesis of the salivary glands.

Adenoid cystic carcinoma of the paranasal sinuses was demonstrated in a patient who subsequently developed a metastatic lesion to both orbits resulting in total blindness. While there are reports of extension of adenoid cystic carcinoma of the lacrimal gland to the adjacent orbit, this patient is an example of orbital extension of an adenoid cystic carcinoma of minor salivary gland originating in a paranasal sinus. The frequency and classification of this tumor also is reviewed.

A microscopic histopathological study was done on 500 full-eyelid-thickness surgical specimens: 25 with the diagnosis of senile ectropion and 25 with that of senile entropion. Five different staining techniques were used. There appears to be significantly more orbicularis and Riolan's muscle ischemia, atrophy, and collagen fragmentation with ectropion than with entropion. Entropion shows more septal and tarsal atrophy. In both conditions, the skin and conjunctiva show chronic inflammation and scarring as a constant feature. Statistical significance at the 1% level was present for all six characteristics studied. These histopathological changes, if not etiological, are at least concomitant features differentiating senile ectropion from entropion at the microscopic tissue level.

Five new cases of metastatic basal cell carcinoma are presented to highlight the potential of this tumor to develop malignant metastases. Histologic criteria of the primary and metastatic site are presented along with a review of the pertinent world literature.

Ceruminoma is a catch-all term that has caused much confusion both in the literature and in clinical practice in regard to the specific histologic diagnosis and proper treatment for tumors arising from the ceruminous glands of the external ear canal. The term ceruminoma has been used in the past to refer to both benign and malignant lesions. To clarify the terminology and better determine appropriate treatment, two cases of benign adenoma of the ceruminous glands along with their histopathologic findings will be presented. The specific characterization of the individual types of ceruminous gland neoplasms, their clinical manifestations, histopathology, and recommended treatment will then be discussed. Finally, suggestions for the appropriate nomenclature for these rare tumors will be reviewed.

This investigation deals with the histogenesis of the so-called 'epimyoepithelial islands' in Mikulicz's disease of the major salivary glands and is based on light and electron microscopic study in six patients. The 'epimyoepithelial islands' represent collapsed acini prior to their complete involution and disappearance, the intraductal cellular proliferation, stratification and differentiation into luminal and peripheral myoepithelial cells with partial and complete obliteration of their lumina and finally, cord-like proliferation and formation of nests of residual pluripotential cells showing squamous metaplasia and occasional myoepithelial cell differentiation. A pink, homogeneous and hyaline material on light microscopic examination is multilayered and extracellular and is in close association with the basal lamina when viewed with electron microscope.

A monomorphic adenoma (ductal type) of the palatal minor salivary glands is reported. Ultrastructurally, the predominant tumor cells contained zymogenlike dense secretory granules. There was a continuum from tumor cells with little or no secretory granules to ones with increasing numbers of granules. Except for that, the tumor cells shared many of their fine structural features. Histogenetically, the tumor originated from neoplastic proliferations of "undifferentiated" stem cells corresponding to "end-bud" stage of salivary glands embryogenesis. Under neoplastic influences, such cells underwent further cytodifferentiation and functional maturation along the secretory cell lines. In mature salivary glands, such pluripotential cells reside as "reserve" cells in the intercalated ducts.

In a 66-year-old woman, a large solitary neurofibroma arising in the right infraorbital nerve extended into the maxillary antrum and the orbit. Following extirpation of this rare tumor, bony defects of the right orbital floor and inferior orbital rim were repaired with a biplanar supramid implant.

The myoepithelium in human parotid, unlike that in other species, is not limited to the acinar-intercalated ductal system but extends to the intra- and extralobular striated ducts. Myoepithelial cells of the striated ducts are smaller, fewer, and different in shape but they are similar in their relationships and ultrastructural morphology to the acinar-intercalated system. Distribution of myoepithelium is discussed with respect to its role and participation in the histogenesis of salivary gland tumours, especially those of intermediate and large duct cell origin.