Sateesh Satchidanand

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.

Colonic Ischemic Necrosis Following Therapeutic Embolization

Transcatheter embolization of the middle colic artery for diverticular bleeding was followed by ischemic necrosis in the transverse colon at the site of previous anastomosis and stricture formation. This is a potential complication of intra-arterial embolization for colonic bleeding.

Light and ultrastructural studies of renal oncocytic adenoma

An asymptomatic renal oncocytoma was found in the upper left quadrant of an eighty-five-year-old woman during a routine physical examination. Ultrastructurally, the tumor was composed entirely of epithelial cells filled with normal and abnormal mitochondria. Selective renal angiography showed two renal arteries supplying a lobulated, highly vascular mass. The mass contained irregular and tortuous vessels without any arteriovenous shunting.

Malignant juxtadrenal schwannoma

We believe we report the first case of malignant juxtadrenal schwannoma. This rare tumor was discovered incidentally in a patient who presented with fever, mental confusion, weight loss, leukocytosis, and elevated erythrocyte sedimentation rate. Preoperative radiographic and endocrine evaluations were suggestive of a nonfunctioning adrenal tumor. Its suprarenal location was unequivocally demonstrated by CT scan, sonography, angiography, and magnetic resonance imaging studies. Angiography revealed that the tumor derived its blood supply from the adrenal and renal vessels. The final diagnosis and its juxtadrenal origin was confirmed by histologic and immunohistochemical studies. A review of the literature on retroperitoneal schwannoma is included.

Arteriovenous malformations as a cause of gastrointestinal bleeding: the importance of triple-vessel angiographic studies in diagnosis and prevention of rebleeding.

Arteriovenous malformations of the gastrointestinal tract are a source of upper and lower gastrointestinal bleeding. We studied 40 patients with arteriovenous malformations. Eighteen percent had single lesions in either the distal transverse colon or the left colon (the angiographic distribution of the inferior mesenteric artery). Seventeen percent had concomitant colonic and extracolonic arteriovenous malformations. Only 6% of those who underwent surgery for removal of arteriovenous malformations rebled. We also studied the incidence of angiodysplastic lesions of the colon of 159 patients over the age of 55 with lower gastrointestinal bleeding; associated arteriovenous malformations were present in 21%. These data suggest: that to evaluate arteriovenous malformations as a cause of gastrointestinal bleeding, one must perform inferior and superior mesenteric and celiac angiography; the incidence of rebleeding is reduced when triple-vessel selective visceral angiography precedes surgical removal of arteriovenous malformations; and the incidence of associated arteriovenous malformations approaches that of diverticulosis in elderly patients with lower gastrointestinal bleeding.

A functional parathyroid gland adenoma of transitional oxyphil cells. A light and ultrastructural study

&NA; This report describes light and ultrastructural features of a functional parathyroid gland adenoma, principally composed of transitional oxyphil cells, in a 64‐yr‐old hypertensive black woman. She was hospitalized for repeated episodes of headaches, lethargy, and dizzy spells. Her serum calcium level was 2.92 mmol/l and immunoassay for parathormone was 390 pg/ml. On neck exploration, the left lower parathyroid gland was found enlarged and therefore removed in toto. The serum calcium and phosphate levels returned to normal following parathyroidectomy. Microscopically, the diagnosis of functional oxyphil adenoma was made. On ultrastructural examination, the tumour was composed principally of transitional cells, occasional typical, and degenerating oxyphil cells. The predominant transitional cells were rich in mitochondria and contained multiple active Golgi complexes, stacked profiles of rough endoplasmic reticulum, and a few secretory granules. On the other hand, typical oxyphil cells were tightly packed with mitochondria at the expense of other organelles. It appeared that neoplastic oxyphil cells were chief eel Is transformed in response to some unknown oncogenic stimulus.

Anal duct/gland cyst

PURPOSE: The purpose of this communication is to report a case of anal duct/gland cyst and review cases of perianal and presacrococcygeal mucus-secreting cysts reported in the literature with emphasis on their histopathologic features. METHOD: Our patient presented with coccydynia. An extraluminal retrorectal tumor was felt on rectal examination. A computerized tomographic scan demonstrated a presacrococcygeal mass closely related to the anorectal junction. The tumor and the coccyx were excised using a posterior approach. Cases of perianal and presacroccygeal mucus-secreting cysts reported in the literature were reviewed. RESULTS: In our case, the tumor proved to be an anal duct/gland cyst. Some of the reported cases of presacrococcygeal glandular cysts had histopathologic features suggestive of anal duct/gland origin. CONCLUSION: Diagnosis of anal duct/gland cyst is based on routine histologic features, histochemical characteristics of mucus, and/or the presence of a communication with an anal duct or crypt. Based on these criteria, some of the reported cases of mucus-secreting cysts occurring around the anorectum may prove to be anal duct/gland in origin.