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PubMed2005

Loss of heterozygosity occurs predominantly, but not exclusively, in the epithelial compartment of pleomorphic adenoma.

Pleomorphic adenoma (PA), being the most common benign tumor of the salivary glands, is composed of epithelial and mesenchymal compartments. In this study, we analyzed 19 microsatellite markers from chromosomal arms 6q, 8q, 9p, 12q, and 17p in 31 PAs and 3 carcinoma ex pleomorphic adenomas (CXPAs) as well as 11 other non-PA-related carcinomas of the salivary gland for comparison. In our analysis, we differentiated between epithelial and mesenchymal tissues. Loss of heterozygosity (LOH) in PAs was most often found in 8q (32%) and 12q (29%). Two of the three CXPAs displayed allelic loss at all chromosomal arms investigated, whereas the results of the non-PA-related carcinomas were rather heterogeneous. LOH could not only be detected in the epithelial, but also in the mesenchymal, compartments of a subset of PAs, especially at chromosomal arm 8q. Concerning the CXPAs, we were able to demonstrate allelic losses not only in the malignant epithelial compartment, but also in the residual adenoma parts. Our data give further evidence that alterations in 8q may be an early event in PA tumorigenesis, whereas LOH in 12q may characterize cells with the potential to transform in CXPAs.

Adenoma, Pleomorphic↗
PubMed1994

Pleomorphic adenoma of the lacrimal gland manifesting as exophthalmos in adolescence--case report.

A 16-year-old girl presented with a pleomorphic adenoma of the lacrimal gland manifesting as left painless exophthalmos which had persisted for 3 years. Computed tomography revealed a tumor about 15 mm in diameter in the superolateral site of the left orbit. The tumor was removed completely by combined orbitofrontal craniotomy through a transcranial approach. Histological examination demonstrated the growth of tumor cells as glandular cavities or sheets, with myxoid and partly chondroid connective tissue stroma. Pleomorphic adenoma of the lacrimal gland is unusual in adolescents.

Adenoma, Pleomorphic↗
PubMed2005

Stereotactic radiosurgery for recurrent pleomorphic adenoma invading the skull base--case report--.

A 38-year-old man presented with a recurrent pleomorphic adenoma in the parapharyngeal space invading the skull base 19 years after the first operation for a parotid gland tumor. Stereotactic radiotherapy was performed to control the tumor growth using a marginal dose of 8 Gy and maximum dose of 18 Gy with care taken to minimize the dose to nearby structures. The symptoms were reduced within a few months. Magnetic resonance imaging over 5 years showed that the tumor was controlled with no regrowth. Stereotactic radiotherapy is a therapeutic option for the treatment of pleomorphic adenomas.

Adenoma, Pleomorphic↗
PubMed1996

Stromal bone formation in pleomorphic adenoma of minor salivary gland origin.

We report an unusual case of pleomorphic adenoma with multifocal stromal bone formation, occurring in the upper lip of a 44-year-old Japanese woman. Islands of fibrous bone were in direct contact with stromal fibrocytes and parenchymal epithelial cells. A review of the literature revealed that stromal bone formation in pleomorphic adenoma of minor salivary gland origin is exceedingly rare.

Adenoma, Pleomorphic↗
PubMed1985

An electron microscopic histochemical study of the histogenesis of major salivary gland pleomorphic adenoma.

Six pleomorphic adenomas were studied histochemically by electron microscopy after staining with ruthenium red, high iron diamine-thiocarbohydrazide-silver proteinate (HID-TCH-SP), and tannic acid-ferric chloride (TA-FeCl3); the latter two are quite specific for sulfated glycoconjugates. With ruthenium red staining, the proteoglycans of the myxochondroid stroma could be visualized as numerous extracellular 25 to 50-nm polygonal matrix granules with fine projecting filaments. Similar positive ruthenium red-stained intracellular granules were observed within the Golgi-derived vacuoles of the modified "myoepithelial" cells in the myxochondroid region. Secretion of these granules by exocytosis was occasionally observed. The modified myoepithelial cell in the myxoid region exhibited strong HID-TCH-SP- and TA-FeCl3-reactive sites within the Golgi-derived vacuoles. The intercellular space or microcyst of the cellular clusters and the extracellular matrix granules stained strongly positive with both HID-TCH-SP and TA-FeCl3. Some cells located at the periphery of the cellular clusters also showed similar but weaker reactive sites. No staining was obtained in neoplastic ductal epithelium. The above cytochemical observations indicate that the modified "myoepithelial" cell probably derives from the periphery of the cellular clusters and is the cellular source of the stromal matrix. Moreover, the observations are compatible with the histogenetic model recently proposed by Dardick et al. that the neoplastic, modified myoepithelial cell is the principal proliferating cell in pleomorphic adenoma.

Adenoma, Pleomorphic↗
PubMed1997

Pleomorphic adenoma of the trachea.

A case of salivary gland type pleomorphic adenoma of the trachea in a 48-year-old woman is presented. Pleomorphic adenoma is extremely rare in the trachea. The behavior of this tumor in the trachea appears to be similar to its counterpart in other sites and distinctly different from the more frequently encountered epithelial tumors.

Adenoma, Pleomorphic↗
PubMed1993

[The matrical fibrous structure in pleomorphic adenoma of the parotid gland--three dimensional visualization by the freeze-fracture deep-etch replica method].

Three dimensional visualization of the matrical fibrous structure of pleomorphic adenomas of the parotid glands was performed by the freeze-fracture, deep-etch replica method(D-E). Three types of fine architecture, two in the myxoid area and one in the chondroid area, which could not be observed by ordinary transmission electron microscopy (TEM), were revealed. In addition, granular connections between the tumor cell membrane and matrical fibers, probably cell surface proteins, were visualized. In the myxoid area, one type of matrix which has a structure that cannot be identified on TEM, D-E demonstrated a uniform fine fibrous network consisting mainly of 7-10 nm diameter filaments and various architectures. These structural components were interlinked in a specific order and formed a basement membrane-like structure which contained the so-called 'hexagon-lattice structure' reported by Sawada. Another type which appears as an irregular spotty structure and a few collagen-bundles on TEM, was revealed by D-E to be composed of a fine fibrous network and collagen-bundles. The collagen-bundles and the network were also interconnected to form a more complicated network. In the chondroid area, the type of matrix appearing as a mottled amorphous area consisting of electron-dense and electron-lucent parts on TEM, was shown by D-E to be composed of mainly collagen-bundles and a less prominent fine fibrous network. As for the cell surface, there were numerous granular structures which were seen to be anchored within the membrane and rigidly connected with 7-10 nm diameter fibrils. However, direct connections between the cell membrane and collagen-bundles were unremarkable. No tumor cell basement membrane was observed. These findings indicate that, in constructing the tumor tissue and maintaining the tumor cells, the matrix could preserve suitable environment for these cells, and that the matrix and tumor cells may influence each other. To date, the matrix of this tumor has been regarded as a relatively uninteresting element. It was thought to lack any apparent structure and have little involvement in tumor biology. We, on the other hand, believe that this tumor matrix is an important component, and that future investigation of this matrix will provide new insights into the study of pleomorphic adenoma.

Adenoma, Pleomorphic↗
PubMed1993

[Immunohistopathological properties of cytoskeletal proteins and extracellular matrix components in pleomorphic adenomas of salivary glands].

Twenty-five pleomorphic adenomas and 10 normal salivary glands were immunohistochemically studied with respect to cytoskeletal proteins and extracellular matrix components to observe the relationship between these components and the differentiation of tumor cells in pleomorphic adenomas. For immunohistochemical observation, keratin (AE1), vimentin (V9), alpha-smooth muscle actin (1A4) and type IV collagen (JK-199) were studied by means of monoclonal antibodies, and laminin (LM) and fibronectin (FN) were analysed with polyclonal antibodies. AE1 was localized in inner tubular cells, and 1A4 was identified in spindle and leiomyomatous cells. These observations may provide evidence of differentiation into ductal epithelia and myoepithelial cells, respectively. Positive staining for V9 in cuboidal cells suggests dedifferentiation. The extracellular matrix components, JK-199, LM and FN, were localized in surrounding areas of cells stained by V9 and/or 1A4. This suggests that expression of these cytoskeletal proteins and extracellular matrix components may affect each other, and ther by contribute to cellular differentiation and production of extracellular matrix.

Adenoma, Pleomorphic↗
PubMed2003

Pleomorphic adenoma of the breast. A case report and distinction from mucinous carcinoma.

Pleomorphic adenoma of the breast is a rare, benign tumor accounting for 68 cases in the literature. It is most commonly seen in postmenopausal women and is characterized by an admixture of epithelial and myoepithelial cells embedded in abundant myxomatous stroma. Its clinical and histologic appearance can be challenging and may lead to a misdiagnosis of invasive carcinoma. We report a case of mammary pleomorphic adenoma in an asymptomatic 59-year-old woman and briefly discuss its distinction from mucinous carcinoma through the use of special stains.

Adenocarcinoma, Mucinous↗
PubMed2003

Primary pulmonary pleomorphic adenoma. An immunohistochemical study and review of the literature.

Primary pleomorphic adenoma of the lung is an uncommon condition. We present a case of primary pulmonary pleomorphic adenoma and its immunohistologic features. The presence of immunoreactivity to both anticytokeratin and antivimentin antibodies for its epithelial components is suggestive of a primary pulmonary lesion. Its high proliferation index and its immunoreactivity to tumor regulatory gene p16(INK4A) are features that, to our knowledge, have not been reported previously. They may have a role in the frequent recurrence of these tumors many years after their apparently complete excision. Detailed genetic investigation and long-term follow-up of this rare tumor will aid in the characterization of its biologic profile.

Adenoma, Pleomorphic↗
PubMed1999

Unusual presentation of a salivary pleomorphic adenoma: a case report and review of the literature.

Although pleomorphic adenomas are the most common neoplasms of salivary gland origin, our knowledge of the etiology, growth, and recurrence patterns, and significance of the varying histologic features of these tumors, remains limited. We present the case of a 66-year-old man with an unusual presentation of a pleomorphic adenoma, and review the important clinical and pathologic features of this entity.

Adenoma, Pleomorphic↗
PubMed1999

Pleomorphic adenoma gene 1 is expressed in cultured benign and malignant salivary gland tumor cells.

The pleomorphic adenoma gene 1 (PLAG1) is activated by reciprocal chromosomal translocations involving 8q12 in a subset of salivary gland pleomorphic adenomas. PLAG1 encodes a zinc finger protein and was initially reported to be expressed in placenta and fetal tissues, with no detectable expression in other normal adult tissues. By Northern blotting we have detected PLAG1 expression in a wide set of normal adult tissues, including heart, placenta, spleen, prostate, testis, ovary, and small intestine. We have performed reverse transcriptase-PCR and Northern blot analyses to study the expression of PLAG1 in normal salivary gland tissues and in primary cultures and cell lines derived from salivary gland tumors. PLAG1 was expressed in all tumor-derived primary cultures and cell lines, irrespective of their histological type or the presence of genomic rearrangements involving PLAG1, but was not detected by our assays in normal salivary glands. Our data indicate that the presence or absence of PLAG1 expression is not an unequivocal marker for the differential diagnosis of benign versus malignant salivary gland tumors, and that a simple de novo activation of this gene does not fully explain the involvement of this gene in salivary gland tumors.

Adenoma, Pleomorphic↗
PubMed1999

[Pleomorphic adenoma of the nasal septum: a case report].

We report on a case of pleomorphic adenoma involving the nasal septum, in a caucasian woman aged 23, who presented with nasal obstruction and epistaxis. A swelling of the anterior part of the nasal septum was observed and a biopsy demonstrated the existence of a pleomorphic adenoma. CT scan and MRI investigation showed the lesion to be limited, and removal was therefore possible using an endonasal approach. No recurrence has been found after 22 months.

Adenoma, Pleomorphic↗
PubMed1999

[Pleomorphic adenomas in the materials of the Department of Otolaryngology of the Academy of Medical Sciences in Poznań].

In the years 1958-1997 were surgically treated in the Department of Otolaryngology Karol Marcinkowski University of Medical Sciences in Poznań 365 patients with pleomorphic adenomas. Majority of the tumors originated of the major salivary glands was parotid gland (273 cases). The given materials confirms the viewpoint that enucleation in the pleomorphic adenomas of the parotid salivary gland--based on total removal of the tumor together with the capsule and pouch constitute a completely sure surgical procedure.

Adenoma, Pleomorphic↗
PubMed2000

[Giant pleomorphic adenoma in accessory salivary gland].

Giant pleomorphic adenoma is the most common neoplasm of salivary glands, specially of parotitis. Less frequently derives from minor salivary glands and, in the case, its size is small. We report one case of pleomorphic adenoma of great mass seated in a palatine salivary gland and avail the opportunity to review these sort of tumors.

Adenoma, Pleomorphic↗
PubMed2000

[Mixed tumor (pleomorphic adenoma) of head and neck. Typical and atypical patterns].

Pleomorphic adenoma is a benign growth frequently encountered in major salivary glands, although minor salivary glands sometimes can be affected. In the latter non-specific clinical signs allows only the postoperative diagnosis. Nevertheless the existence of lesser salivary glands outside the oral cavity, and therefore pleomorphic adenomas, justify the specialist's need of its knowledge because of the difficulties arising in differential diagnosis. The AA. present a review of 22 cases in various sites treated in their Department in a 9 year-term.

Adenoma, Pleomorphic↗
PubMedDate not supplied

[Pleomorphic adenoma in ectopic salivary tissue in a child]].

Benign tumors appearing in cervical ectopic salivary tissue are rare. Most of these tumors are pleomorphic adenomas and many occur in adults. We report two cases of pleomorphic adenoma developing in cervical ectopic salivary tissue in children and review the pathogenesis of salivary heterotopia and these benign tumors.

Adenoma, Pleomorphic↗
PubMed2001

Pleomorphic adenoma of the nose.

Pleomorphic adenoma is the most frequent tumor of the major salivary glands. It is rarely located in the lacrymal glands and is unusual in the nasal cavity. A rare case of a pleomorphic adenoma of the nose is presented along with a review of the literature. The use of nasal endoscopy in removing tumors of the nose and paranasal sinuses is discussed.

Adenoma, Pleomorphic↗