Anand P. Chaudhry

Melanotic neuroectodermal tumor of infancy: An ultrastructural study, literature review, and reevaluation

Two cases of melanotic neuroectodermal tumor of infancy were examined by electron microscopy and an extensive review of the literature was performed. Ultrastructural examination revealed several features not previously described for this lesion. Three different types of melanin granule formation were observed, many cells had a single cilium, and cell junctions of the “close” or “modified‐tight” type were seen, but no desmosomes were found. The morphologic data were consistent with the concept that the tumor arises from neural crest cells. The review of the literature indicated that there have been 158 reported cases of this lesion, including the two reported here. There were five cases of malignant tumor reported for a rate of 3.2%. This rate of malignancy is very high in view of the fact that the tumor has been described as universally benign. The significance of this finding is discussed with regard to melanin‐producing lesions of the oral cavity.

Histogenesis of adenoid cystic carcinoma of the salivary glands: light and electronmicroscopic study

This ultrastructural study, based on 12 cases of adenoid cystic carcinoma of the major and minor salivary glands, was conducted to determine the role and extent of participation of myoepithelial cells in their histogenesis. The tumors were composed of four major cell types: intercalated duct, myoepithelial, secretory, and pluripotential reserve/stem cells. The cellular composition of adenoid cystic carcinoma is similar to that in the “terminal tubule” complex stage of a developing salivary gland except that in the tumor the pluripotential reserve/stem cells differentiate predominantly along the intercalated duct cell line rather than secretory cells as in the acinic cell carcinoma. Furthermore, adenoid cystic carcinoma appears to contain a far greater number of myoepithelial cells than acinic cell carcinomas. Cancer 58:72–82, 1986.

Myoepithelial cell adenoma of the parotid gland: A light and ultrastructural study

Light, histochemical, and ultrastructural features of a myoepithelial cell adenoma of the parotid gland are described. Ultrastructurally, the neoplasm was almost entirely composed of myoepithelium. The spindle‐shaped myoepithelial cells and their processes were filled with longitudinally oriented myofilaments with characteristic densities along their course and marginal attachment plaques. The tumor cells were interconnected by desmosomes. The role of myoepithelium in the genesis of some salivary gland tumors is discussed.

Glycogen‐rich tumor of the oral minor salivary glands a histochemical and ultrastructural study

A detailed electronmicroscopic study on glycogen‐rich tumor is presented. The neoplasm originated from the minor salivary glands on the ventral surface of the tongue. The role of myoepithelial cells in the histogenesis of this lesion is not supported. It is proposed that the tumor arises from “undifferentiated” stem cells analogous to cells in the “end bud” stage of salivary gland morphogenesis. The presence of a large amount of glycogen is secondary to defective carbohydrate metabolism within the tumor cells. Cancer 52:105‐111, 1983.

Monomorphic adenomas of the parotid glands their ultrastructure and histogenesis

Three cases of monomorphic basal cell adenoma of the parotid glands were studied with light microscopy. In one patient, fresh tissue was available for electron microscopic observations. On the basis of ultrastructural findings it was concluded that myoepithelial cells play little, if any, role in the histogenesis of this lesion. The tumor originates from the undifferentiated stem cells analogous to the cells seen at the “end bud” stage of salivary gland morphogenesis prior to their further cytodifferentiation and functional maturation into secretory and myoepithelial cells. In fully developed salivary glands such undifferentiated stem cells reside as “reserve” cells in the intercalated ductal system. Cancer 52:112‐120, 1983.

A nonfunctioning paraganglioma of vagus nerve: an ultrastructural study.

The clinical, histological, and ultrastructural aspects of a cervical paraganglioma of the vagus nerve, in a 66‐year‐old white man, have been discussed in detail. Ultrastructurally, the tumor chief cells contained characteristic membrane‐bound and dense‐cored neurosecretory granules which ranged in size from 85 mμ to 190 mμ Unlike earlier ultrastructural reports, the present study showed the presence of sustentacular or supporting cells. These cells were smaller, darker, polymorphic, and were commonly located at the periphery of a single or group of chief cells. Furthermore, unlike earlier reports on vagal paragangliomas, nonmyelinated nerve fibers and an occasional axon were identified in the present fine structure study.

Granulomatous laryngitis of unknown etiology

A 21‐year‐old man was admitted for odynophagia and hoarseness of four months duration. He smoked one and a half packs of cigarettes a day and occasionally inhaled marijuana. Indirect laryngoscopy revealed a massive swelling of the entire epiglottis, aryepiglottic folds, and arytenoids. The histopathologic diagnosis of chronic but active nonspecific inflammation was made. Combined antibiotics and steroid therapy gave temporary relief. He was readmitted several months later with progressive shortness of breath, dysphagia, and hoarseness. Biopsy of the epiglottic tissues showed multiple noncaseating epithelioid granulomatous lesions consistent with sarcoidosis. All pertinent laboratory tests failed to establish a definitive diagnosis. The patient eventually underwent supraglottic laryngectomy. He has been symptom‐free for 20 months following surgery.