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I Dardick

Publications and source records attributed to I Dardick.

At least 19 recordsLinked to original sources
PubMed1992

Immunohistochemical and ultrastructural correlates of muscle-actin expression in pleomorphic adenomas and myoepitheliomas based on comparison of formalin and methanol fixation.

The degree and range of differentiation of the cells referred to as myoepithelial-like in pleomorphic adenomas and the tumour cells of myoepitheliomas are not definitely established. This type of information is critical for establishing reliable diagnostic criteria, such as expression of muscle-specific actin and ultrastructural identification of myofilaments, in these and other salivary gland tumours. Pleomorphic adenomas (18) and myoepitheliomas (5), of which 10 cases were fixed only in formalin and 13 cases where tissues were fixed in both formalin and methanol/acetic acid, were studied. Each tumour and normal accompanying parotid was immunostained with two monoclonal antibodies for smooth muscle actin, HHF35 and MSA. Staining of myoepithelial cells was absent in certain samples of normal gland with both HHF35 (15%) and MSA (69%) when formalin-fixed tissue was used. Using formalin-fixed tissue from 15 pleomorphic adenomas/myoepitheliomas, 2 (14%) had focal positivity with HHF35, while 8 cases (57%) were positive with MSA. However, a certain degree of false positivity was suspected since in samples of normal parotid, both acinar and duct cells were frequently stained, particularly with MSA. With methanol/acetic acid-fixed tissue only 4 of 13 cases (31%) were positive with either MSA or HHF35 and 2 of these only had a minor proportion of the tumour cells expressing muscle-specific actin. Using alcohol-fixed tissue, myoepithelial cells were strongly stained in all examples of normal parotid gland with both anti-actin antibodies. In 5 cases examined by electron microscopy, there was no apparent correlation between immunohistochemical results and the presence or absence of cytoplasmic filament accumulation. The results indicate considerable tumour cell heterogeneity in muscle-specific actin expression and suggest that non-luminal cells in pleomorphic adenomas and the tumour cells in myoepitheliomas may differentiate as classical myoepithelial cells, as partially differentiated (i.e. modified myoepithelial cells) or as the counterpart of basal cells present in the intra- and interlobular ducts of normal salivary gland.

Actins↗
PubMed1992

The pathobiology of salivary gland. II. Morphological evaluation of acinic cell carcinomas in the parotid gland of male transgenic (MMTV/v-Ha-ras) mice as a model for human tumours.

In the transgenic TG.SH (mouse mammary tumour virus/v-Ha-ras) mouse, designed to develop mammary tumours, occasional spontaneous salivary gland tumours have been reported, predominantly in males. The incidence and histomorphology of salivary gland tumours in 73 TG.SH mice were surveyed and in total, 21.9% developed both overt and microscopic parotid tumours. The majority developed between 73 and 150 days of age. In 31.5% of the TG.SH mice, occasional unilateral, but more frequently bilateral exophthalmos due to hyperplasia of the intraorbital (Harderian) lacrimal gland was observed. In 70% of these animals, parotid tumours developed later. Since Harderian gland hyperplasia, occurring as early as 5 weeks of age, preceded the development of palpable salivary gland lesions, this stigma is useful for the early selection of animals likely to progress to tumour formation. Before tumour-bearing transgenic mice are considered to be suitable models of human neoplastic disease, morphological characterization is necessary to ensure that the tumours are histologically representative of the human lesions for which they are potential models. In this study, all parotid tumours consisted of acinar-like glandular structures with central lumina discernible by electron microscopy. Ultrastructurally, secretory granules evident in the apical cytoplasm of the tumour cells resembled the zymogen granules of the normal parotid acinar cell, and some cells had a prominent complement of rough endoplasmic reticulum. These features, along with focal amylase expression detected immunohistochemically in some parotid tumours, identified these neoplasms as acinic cell carcinomas that mimic the human salivary gland acinic cell carcinoma faithfully.

Animals↗
PubMed1992

Trabecular and solid-cribriform types of basal cell adenoma. A morphologic study of two cases of an unusual variant of monomorphic adenoma.

Monomorphic adenomas are a morphologically complex group of salivary gland tumors. Two unusual examples, one a trabecular and the other a solid form of basal cell adenoma, reveal the development of a cribriform growth pattern focally in the former example and diffusely in the latter. They illustrate the potential for cellular differentiation within this subgroup, organization of synthetic products by the tumor cells, and the histologic criteria useful for the distinction of basal cell adenoma from adenoid cystic carcinoma.

Adenoma↗
PubMed1992

Acinic cell tumour: a metastasis in the lung diagnosed by electron microscopy of aspirated material.

A case of acinic cell carcinoma, metastatic to lung is presented. Fine needle aspiration showed a low-grade adenocarcinoma. Electron microscopy of the aspirated material, however, allowed definite preoperative diagnosis of metastatic acinic cell carcinoma. The lesion was successfully resected and diagnosis confirmed on histology. Ten years previously an acinic cell carcinoma of similar histology had been excised from the left parotid region.

Adenocarcinoma↗
PubMed1992

The need for clinical awareness of polymorphous low-grade adenocarcinoma: a review.

Adenocarcinomas of the salivary glands are a heterogeneous group both in terms of histomorphology and clinical course. One recently described adenocarcinoma, polymorphous low-grade adenocarcinoma (solely of minor salivary gland occurrence), is appropriately named. This neoplasm has a wide spectrum of histology and can resemble tumors such as pleomorphic adenoma and adenoid cystic carcinoma; both aspects can lead to diagnostic problems for the pathologist. As well, despite an infiltrative growth pattern, which frequently results in perineural invasion, this tumor has a low local recurrence rate and a remarkable infrequency of local or distant metastasis. In order to provide appropriate therapy for polymorphous low-grade adenocarcinoma, oral and head and neck surgeons must be familiar with this neoplasm.

Adenocarcinoma↗
PubMed1992

The effect of basic fibroblast growth factor and omentopexy on revascularization and epithelial regeneration of heterotopic rat tracheal isografts.

Donor airway ischemia is a significant problem after clinical lung transplantation despite the use of omentopexy for accelerated local bronchial revascularization. Several growth factors have been shown to induce angiogenesis in vitro and in vivo. In the present study the quantitative effects on tracheal revascularization and epithelial regeneration of omentopexy and continuous local administration of basic fibroblast growth factor were investigated in a heterotopic rat tracheal isograft model. Tracheas were harvested from donor rats and heterotopically implanted into the omentum of syngeneic recipient rats. Animals were randomly assigned to study groups differing only in treatment of the tracheal segments: omental wrap for 2, 7, or 14 days; omental wrap plus continuous local administration of basic fibroblast growth factor for 7 or 14 days; or omental wrap plus local application of saline for 7 or 14 days. Two, 7, or 14 days after the animals were put to death, the vascularity of the tracheal segments and attached omentum and the tracheal epithelial morphology were assessed in a blinded fashion with use of light microscopy and morphometric image analysis. Vascularity in tracheal segments treated with basic fibroblast growth factor was significantly (p less than 0.05) greater than in control tracheas after 7 and 14 days. Epithelial regeneration was also improved in the basic fibroblast growth factor-treated groups at days 7 and 14 (p less than 0.05). We conclude that continuous local administration of basic fibroblast growth factor enhances early revascularization of tracheal segments induced by omentopexy and accelerates epithelial regeneration in a heterotopic rat tracheal isograft model.

Animals↗
PubMed1992

Pharyngeal rhabdomyoma: a clinico-pathological study.

Adult extracardiac rhabdomyomas are rare with only 33 head and neck cases being reported in the world literature. In this select group, only nine cases have been found in the pharynx. We present two cases of pharyngeal rhabdomyoma focusing on the imaging findings, surgical approaches and more specifically on the histopathological and electron microscopic diagnosis of this interesting lesion. It is important to differentiate this tumor from other neoplasms, including granular cell myoblastoma, rhabdomyosarcomas, hamartomas, and fetal rhabdomyomas.

Biopsy↗
PubMed1991

The pathobiology of salivary gland. I. Growth and development of rat submandibular gland organoids cultured in a collagen gel matrix.

Fragments of rat submandibular gland (organoids) which maintained the topological organization of the parent tissue were cultured in a three-dimensional collagen gel matrix for up to 30 days. At 48 h, vigorous peripheral outgrowth had occurred around each organoid. This was accompanied by central necrosis and the bridging of adjacent organoids. By day 5, large cyst-like spaces occupied the centre of many organoids. Bromodeoxyuridine labelling indicated that a considerable proportion of the lining cells were proliferating. Organoid growth peaked at between 5 and 10 days. Thereafter, the number of viable colonies and proliferating cells declined. Addition of isoproterenol after 24 h culture resulted in marked morphological alterations, with earlier and more prolific outgrowth and a greater tendency for organoids to flatten and grow out over the surface of the gel with squamous differentiation. Ultrastructurally, nuclear and cytoplasmic features of isoproterenol-treated and untreated cultures were similar. The secretory granules and extensive rough endoplasmic reticulum of terminal tubule cells, evident in organoids immediately after isolation, were infrequent after 24 h and absent by 48 h. Similar alterations occurred in the few acinar cells, so by 5 days the cultures were composed entirely of a uniform population of primitive, dedifferentiated cells. Further uses of this culture systems will include the study of diseases and disorders of the salivary glands as well as normal growth and differentiation pathways.

Animals↗
PubMed1991

Synovial sarcoma. Inter-relationship of the biphasic and monophasic subtypes.

In order to assess minimum diagnostic criteria for synovial sarcoma, particularly the monophasic variety, and the inter-relationship between the monophasic and biphasic types, 32 examples were studied histologically, immunohistochemically (26 cases), and ultrastructurally (13 cases). Of the six biphasic synovial sarcomas examined by electron microscopy, the spindle cell component did not show evidence of epithelial differentiation or resemble the epithelial phase, but did appear fibroblastic; no tumor cells transitional between the spindle and epithelial component were evident. In contrast, all of the seven monophasic lesions had ultrastructural growth patterns and some cellular features approximating the epithelial cells of the biphasic variant. In 11 biphasic synovial sarcomas, epithelial membrane antigen was detected in the glandular epithelium of all cases and cytokeratins in eight cases; in no case were these antigens detected in the spindle cell regions of biphasic lesions. Of the 15 monophasic synovial sarcomas, two were positive for cytokeratins and four for epithelial membrane antigen. Thus, the detection of epithelial markers either immunohistochemically or by electron microscopy (or both) should be the minimal diagnostic criteria for monophasic synovial sarcomas. Based on these findings, it is suggested that monophasic synovial sarcomas do not represent the spindle cell or "stromal" phase of biphasic synovial sarcomas, but are a poorly differentiated variant of the latter. As others have suggested, these tumors are, in fact, carcinosarcomas and carcinomas of the soft tissues and the designation synovial sarcoma is inappropriate for this tumor class.

Adolescent↗
PubMed1991

Paraganglioma of the vulva.

A case of vulvar paraganglioma is reported. Following presentation with vulvar pain, a 1-cm nodule was excised from the labium minus of a 58-year-old woman. Histologically, the tumor was composed of nests of round eosinophilic cells with moderately pleomorphic nuclei, beneath an intact squamous epithelium. Ultrastructural studies indicated two cell types within the neoplasm: chief cells with numerous small neurosecretory granules and peripheral slender sustentacular cells. A reticulin stain confirmed the "zellballen" nature of the neoplasm, and the neoplastic cells showed moderate argyrophilia on a Grimelius stain. The immunoperoxidase stains for chromogranin and neuron-specific enolase were strongly positive in the neoplastic chief cells. Immunostaining using anti-S-100 antibody confirmed the finding of sustentacular cells by identifying many slender cellular processes among the chief cells. These light and electron microscopic findings are diagnostic of paraganglioma, an entity not previously reported in the vulva to our knowledge.

Cell Nucleus↗
PubMed1991

Two unusual tumours of the gastrointestinal tract in a patient with tuberous sclerosis.

A 16 year old girl with an established diagnosis of tuberous sclerosis presented with a 1 year history of swelling of the left cheek. A 2 cm diameter tumour was excised which showed histological features of a solid variant of a minor salivary gland basal cell adenoma. One year later during laparotomy and excision of multiple renal angiomyolipomas, a 5 cm diameter subserosal tumour was found at the hepatic flexure of the colon. Examination of biopsy material revealed a leiomyoma. This case is presented to demonstrate two tumours that have not to the authors' knowledge been previously described in a young patient with tuberous sclerosis. Although the association may be coincidental, these tumours could represent two rare associations of tuberous sclerosis.

Adenoma↗
PubMed1991

Cellular differentiation and morphologic heterogeneity in polymorphous low-grade adenocarcinoma of minor salivary gland.

Histologic diversity is intrinsic to salivary gland tumors, but it is a particular feature of polymorphous low-grade adenocarcinoma as denoted by the terminology. Application of immunohistochemistry and electron microscopy to three examples allowed the study of some aspects of tumor cell differentiation in this minor salivary gland lesion. In one case where the tumor cells were cytologically of one type, immunohistochemistry clearly identified both luminal and nonluminal tumor cells, but the latter showed no evidence of myoepithelial cell differentiation. A second case revealed differentiation only of luminal-type tumor cells, while a third example was largely differentiated as myoepithelial cells but again immunohistochemistry confirmed focal formation of duct-like structures by luminal epithelium. These cases show a considerable range of tumor cell heterogeneity as well as variations in their organization. This variation in differentiation characteristics underlies the histology of polymorphous low-grade adenocarcinomas, and likely occurs in other salivary gland tumors. To establish specific and reliable diagnostic criteria for such tumors requires awareness of this neoplastic process. The limited malignant potential and excellent survival of patients with polymorphous low-grade adenocarcinoma is apparently little affected by patterns of differentiation in this particular neoplasm.

Actins↗
PubMed1991

S-100 protein antibodies do not label normal salivary gland myoepithelium. Histogenetic implications for salivary gland tumors.

Neoplastically modified myoepithelial cells have a key role in developing the histologic characteristics of some salivary gland tumors. S-100 protein expressed in certain of these tumors is suggested to support this role, as the principal component in the human salivary gland reported to be S-100 protein-positive is myoepithelium. Confirmation of such an important aspect is required. Immunoperoxidase staining of parotid salivary gland shows considerably different patterns obtained with antibodies to S-100 protein, neuron-specific enolase, and neurofilaments compared with those for muscle-specific actin and cytokeratin 14; many more cells and their processes associated with acini and ducts are evident with the latter two antibodies. Double immunofluorescent staining with antibodies to either S-100 protein or neuron-specific enolase combined with muscle-specific actin does not reveal colocalization of these antigens in myoepithelial cells. The former localize only to nerve fibers adjacent to, but separate from, acini, and the latter only to myoepithelial cells. It is apparent that S-100 protein staining of the rich network of unmyelinated nerves in the interstitial tissues, evident ultrastructurally, has been misinterpreted as myoepithelium. This result has important implications for histogenetic classifications of salivary gland tumors.

Epithelium↗
PubMed1990

A spindle-cell myoepithelioma of the lacrimal gland.

A middle-aged woman developed unilateral, painless proptosis that increased slowly over 1 year. A clinical diagnosis of pleomorphic adenoma of the lacrimal gland was supported by computed tomographic scanning and the tumor was excised. On histological examination the tumor proved to be a benign, myxoid myoepithelioma of spindle-cell type. Although occasionally seen in the salivary glands, to our knowledge, this tumor has not previously been described in the lacrimal gland.

Female↗
PubMed1990

Comparative histogenesis and morphogenesis of mucoepidermoid carcinoma and pleomorphic adenoma. An ultrastructural study.

Current classifications of salivary gland tumors separate mucoepidermoid carcinoma from other neoplasms on the basis of a number of histological features, in particular the lack of participation of neoplastic myoepithelial cells. However, ultrastructural examination of low- and intermediate-grade mucoepidermoid carcinomas and pleomorphic adenomas reveals many common organizational and cellular features. Of prime importance is the relationship of intermediate cells to the luminal cells in mucoepidermoid carcinomas, which is remarkably similar to that seen between modified myoepithelial cells and luminal cells in pleomorphic adenomas. The results suggest that intermediate cells of mucoepidermoid carcinoma are the counterpart of the modified myoepithelial cells of pleomorphic adenoma. The generally accepted hypothesis that the former tumor develops from an excretory duct reserve cell, while the latter originates from an intercalated duct stem cell does not seem to be valid; pleomorphic adenoma and mucoepidermoid carcinoma appear to be closely related morphologically.

Adenoma, Pleomorphic↗
PubMed1990

A review of the proliferative capacity of major salivary glands and the relationship to current concepts of neoplasia in salivary glands.

The classification of salivary gland tumors relies heavily on histogenetic postulates. One of these, the semipluripotential reserve cell theory, suggests that certain reserve cells in specific segments of the duct system of major and minor salivary glands are critical to the development of neoplasms in these glands. However, direct evidence in support of this hypothesis is unavailable. This survey of proliferative capacity in normal salivary gland is based on a review of data in the literature, our observations of DNA synthetic and mitotic activity in developing rat and human salivary gland, and autoradiographic studies of induced cell proliferation in rat salivary gland. Autoradiography of neonatal rat salivary gland after tritiated thymidine administration, and electron microscopy of these tissues, reveals that as well as duct basal cells, luminal cells at all levels of the duct system and even acinar cells are capable of DNA synthesis and mitosis. Indeed, in such studies, more luminal than basal cells are seen in mitosis. In adult rat salivary gland induced to undergo hyperplasia, more acinar cells than intercalated duct cells are in the S phase of the cell cycle. However, cycling cells were observed even in striated ducts and, importantly, both basal and luminal cells of major interlobular excretory ducts are also labeled. Similar findings are present in fetal and adult human salivary glands. From such observations, it is evident that dividing cells are not limited to basal cells of excretory ducts and luminal cells of intercalated ducts, so that there is no support for the semipluripotential bicellular reserve cell hypothesis. However, there is considerable evidence for a multicellular theory of tumor histogenesis; that is, any of the multiplicity of cell types in normal salivary gland have the potential to give use to any of the various types of tumor occurring in this organ.

Animals↗