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PubMed1992

Pleomorphic xanthoastrocytoma of the brain: MR findings in six patients.

OBJECTIVE: Pleomorphic xanthoastrocytoma is a rare, usually benign brain tumor. This pleomorphic supratentorial tumor involves the leptomeninges and superficial cortex in young patients with seizures. The MR imaging features of this distinct tumor have not been reported. We describe the MR imaging findings in six patients with pathologically proved pleomorphic xanthoastrocytoma. MATERIALS AND METHODS: We retrospectively reviewed the MR images of six patients with pathologically proved pleomorphic xanthoastrocytoma. MR images were reviewed by two neuroradiologists. The pathologic slides of the tumors were reviewed by two neuropathologists. We also analyzed the patients' clinical features. RESULTS: Most of the tumors were cortical based and isointense with gray matter on T1-weighted images and mildly hyperintense on T2-weighted images. All the masses enhanced with contrast material. Cystic components and gyriform and leptomeningeal enhancement were seen occasionally. The tumors occurred in the temporal lobes in four of the six patients. Three patients had seizures, and the other three had headaches. CONCLUSION: Pleomorphic xanthoastrocytoma is a rare, usually benign, cortical-based mass that often enhances intensely with contrast material. The most common location is in the temporal lobes. Seizures and headaches are common clinical features. Familiarity with this lesion is important in the differential diagnosis of enhancing cortical-based masses.

Adolescent↗

PubMed1991

[A study on development site of pleomorphic adenoma--a rare case report in external nose].

A rare case of pleomorphic adenoma in the external nose is reported. As a result of studies on the correlation between the sites of occurrence of pleomorphic adenomas reported and the sites of secretory glands with myoepithelial cells, it is found that pleomorphic adenomas occur in all secretory glands with myoepithelial cells. There are distinctive differences in the incidence in each part of the body, and in the hollow organs in the digestive and respiratory tracts: it is high in the face and decreases as the sites become farther away from the face. In the integumentary system, it is also high in the face. However, pleomorphic adenomas occurring in secretory glands without myoepithelial cells, and in non-glandular tissue such as the middle ear, paranasal sinuses, mesangial sinuses, vagina and tests can be considered either as those where glandular tissue and myoepithelial cells mingled during development (and thus are ectopic) or as those when invasion into adjacent organs occurred as the pathologic lesion (pleomorphic adenoma) expanded.

Aged↗

PubMed1977

[Hematogenous metastases of benign pleomorphic adenomas of the salivary glands (author's transl)].

Hematogenous metastases of benign pleomorphic adenomas are exceptionally rare. In three secure reports of the world literature metastases occurred in lung, liver or bone after operation of a benign pleomorphic adenoma with the greatest interval of twenty-two years between operation and metastases. This will be interpreted as implantation-metastases. All other observations represented secondary carcinomas in pre-existing pleomorphic adenomas. The morphological criterias of an accurate classification are explained. A number of reports of the literature about metastases of benign pleomorphic adenomas deals with misinterpretations of secondary adenomas in pre-existing pleomorphic adenomas.

Adenoma↗

PubMed2002

[Expression and clinical significance of Fas-FasL of pleomorphic adenoma and adenoid cystic carcinoma in parotid gland].

OBJECTIVE: To determine the expression and clinical significance of Fas and FasL in cases of occurrence and development of pleomorphic adenoma and adenoid cystic carcinoma(ACC) in parotid gland. METHODS: Using Immunohistochemistry techniques and quantitative analysis under computerized system, we investigated Fas-FasL expression in 21 cases of normal parotid gland, 35 cases of pleomorphic adenoma in parotid gland and 32 cases of ACC in parotid gland. RESULTS: All cases of ACC of parotid gland showed Fas and FasL negative expression, no correlation was found between the expression of Fas-FasL and the histological type and the pathological grades of ACC. Although both normal parotid gland and pleomorphic adenoma of parotid gland had distinct expression of Fas and FasL, the positive expression of Fas FasL in pleomorphic adenoma of parotid gland cases were both significantly lowered (P<0.01) than that in normal parotid gland. CONCLUSION: Expression of Fas-FasL and Fas FasL mediated cell apoptosis disturbance had significant correlations with the occurrence and malignant development of pleomorphic adenoma and ACC in parotid gland.

English Abstract↗

PubMed2004

[Recurrences of pleomorphic adenomas of the parotid: development of concepts].

OBJECTIVES: The aim of this study was to examine the surgical and pathological factors that led to recurrent parotid pleomorphic adenomas. The study also tried to determine best practice for the treatment of recurrence. In addition the study looked at the correlation between fine needle cytology and definitive histology. MATERIAL AND METHOD: Histological study was undertaken on 100 pleomorphic adenomas surgically removed from patients in our institution between 1992 and 2002. Study of diagnostic value of fine needle cytology aspiration and MRI for pleomorphic adenoma diagnosis was performed in 181 patients operated on for parotid tumors. RESULTS: Hypocellular pleomorphic adenomas often have a thin capsule and constitute the most frequently encountered histological type in recurrence. Pseudopodias are considered as an additional factor in recurrence. In our series, cytological study had an excellent diagnostic value with a sensitivity of 92% and a PPV of 96%. MRI study had a sensitivity of 83% and a PPV of 89%. CONCLUSIONS: According to these findings, enucleation surgery on a pleomorphic adenoma should not be performed anymore. Parotidectomy techniques (total or lateral) constitute the surgical treatment of choice. Fine needle aspirate cystology in a useful diagnostic procedure. Management of recurrences is based on surgery with total parotidectomy and facial nerve preservation. Role of radiotherapy is still indeterminate.

Adenoma↗

PubMedDate not supplied

Pleomorphic adenoma of the salivary glands: analysis of 94 patients.

UNLABELLED: Pleomorphic adenoma is a benign epithelial tumor of adenoid structure preferentially arising from the parotid gland. It was shown that complete tumor excision is a curative measure and recurrence is likely in incompletely excised tumors. The aim of this study was to analyse the outcome of patients with pleomorphic adenoma from salivary glands in order to evaluate the surgical strategy of a single institution. MATERIALS AND METHODS: The files of 94 patients were evaluated. Special attention was given to the development of malignancy in pleomorphic adenoma. RESULTS: The pleomorphic adenoma preferentially originated in the parotid gland (n=73; right 48, left: 25), and rarely in other glands. The tumor occurred more often in females than in males (45:28, parotid). In 73 patients a slowly growing swelling of the parotid was first noted, which was located at different sites within the gland. At least one recurrence was noted in 18 patients, the majority of them aged 50 to 70 years (n=12). Malignant transformation to carcinoma was found in 8.5%. CONCLUSION: Pleomorphic adenoma from salivary glands is a benign tumor. However, in a noteworthy number of patients, inside the benign tumor a phenotype develops with distinct properties of malignancy. Surgery with safety margins is the therapy of choice. Multinodular tumors are prone to recurrent disease.

Adenoma↗

PubMed1991

Glial fibrillary acidic protein expression in pleomorphic adenoma, chordoma, and astrocytoma. A comparison of three antibodies.

Glial fibrillary acidic protein (GFAP) is a major constituent of glial cytoplasmic intermediate filaments. Glial fibrillary acidic protein expression has been accepted as a marker of astroglial differentiation or origin. However, GFAP expression has been demonstrated in a variety of normal and neoplastic tissues outside the central nervous system, including pleomorphic adenomas, chordomas, bone, and cartilage. It has been postulated that coexpression of GFAP and vimentin in neoplastic myoepithelial cells in pleomorphic adenomas reflects early chondroid differentiation. Glial fibrillary acidic protein expression in chondromyxoid and chordoid tumors was studied in formaldehyde solution-fixed, paraffin-embedded sections of 20 pleomorphic adenomas and 10 chordomas by the immunoperoxidase method with the use of commercially available monoclonal (n = 2) and polyclonal (n = 1) antibodies. All pleomorphic adenomas and chordomas demonstrated expression of GFAP with the use of the polyclonal antibody (Biomeda Corp [Foster City, Calif]). Variable expression of GFAP was present in 90% (18/20) and 70% (14/20) of pleomorphic adenomas, and in 20% (2/10) and 0% of chordomas, with the use of the two monoclonal preparations (Dakopatts [Glostrup, Denmark] and BioGenex Laboratories [San Ramon, Calif]), respectively. Normal brain tissue and eight astrocytomas were used as "controls" to compare staining intensity and quality between the polyclonal and monoclonal anti-GFAP antibodies. Glial fibrillary acidic protein positivity with the polyclonal antibody was more intense than that with either monoclonal antibody despite similar (congruent) distributions of tumor cell types that were stained in control brain and astrocytoma tissues. The GFAP polyclonal antibody was more frequently immunoreactive than the monoclonal antibodies, particularly in cells that exhibited chondroid differentiation. These findings may have practical application in surgical pathology.

Antibodies, Monoclonal↗

PubMed1975

Pleomorphous macrocellular pulmonary carcinomas. An anatomoclinical study on 193 cases.

A pathomorphologic study was carried out by the conventional histologic methods in 193 cases of pleomorphous macrocellular pulmonary carcinoma, of a total of 1,637 cases of lung cancer diagnosed histologically between January 1, 1961 and December 31, 1974. In comparison to other histologic types, the incidence of macrocellular carcinomas was of 11.8%, 62.6% belonged to the 40-60 years age-group, with male predominance. The results showed this carcinoma to be an autonomous type of neoplastic proliferation. The pathomorphologic particularities observed in the 193 cases and their evolution are conclusive arguments for considering pleomorphous macrocellular carcinomas as a separate histologic type in the classification of lung cancers. The term of pleomorphous macrocellular carcinoma appears to be the most comprehensive and in keeping with the histologic structure of these tumours. Cellular pleomorphism is an important diagnostic feature. Zones of specific differentiation observed in some cases may be included in the pleomorphism of these carcinomas. Notions of histogenesis are likewise discussed. It is increasingly assumed that these carcinomas are morphologically the expression of a cellular proliferation, differentiation and maturization response to the action of complex factors. The reduced stroma of these carcinomas indicate a more rapid increase of the tumoural parenchyma.

Carcinoma, Small Cell↗

PubMed1986

Pleomorphic xanthoastrocytoma. Immunohistochemical methods for differentiation from fibrous histiocytomas with similar morphology.

Three cases of primary intracranial tumours fulfilling the clinical and histological criteria of pleomorphic xanthoastrocytoma are presented. As is typical, they occurred in young people, aged 15, 17, and 22 years, and were composed of lipid-laden pleomorphic cells with frequent bizarre multinucleated forms and a prominent reticulin network. However, subsequent immunohistochemistry, further histological review, and clinical follow-up suggest that these tumours were different entities. In one case the tumour cells were negative for GFAP but positive with a panel of histiocytic markers. The lesion, which extended rapidly and caused death within 6 months, was assumed to be a true meningeal fibrous histiocytoma. The remaining two cases were positive for glial fibrillary acidic protein (GFAP) and S100 protein. One of these was mitotically active, contained areas of necrosis and vascular proliferation, and also led rapidly to death. This, we concluded, was a glioblastoma. The third case showed little mitotic activity and the patient remains well; this is probably a true pleomorphic xanthoastrocytoma. These results indicate that tumours with light-microscopic appearance of pleomorphic xanthoastrocytoma require detailed immunohistochemical investigation. Only those lesions with low mitotic activity and undoubted evidence of glial origin should be accepted as true pleomorphic xanthoastrocytoma. Extensive necrosis in a tumour with GFAP-positive, lipid-rich cells indicates a lipidised glioblastoma, while positive histiocytic immunocytochemistry should suggest a fibrous histiocytoma.

Adolescent↗

PubMed1981

Histopathologic studies on carcinoma in pleomorphic adenoma of the parotid gland.

Five-hundred-eighteen cases of primary epithelial tumors of the parotid gland were examined. The incidence of carcinomas in pleomorphic adenoma was 9.3% (48 cases). In addition to cellular atypism, the following histological findings were thought to be important criteria for the diagnosis of carcinomas: (1) capsular invasion, (2) infiltration into adjacent organs, (3) proliferation of atypical cells within fibrous tissues and chondroid matrix in the area of pleomorphic adenoma, (4) vascular involvement, and (5) mitotic figures. Pleomorphic adenomas (282 cases) were found predominantly in females (70.8%), at the age of 30 to 49 (48.2%), whereas carcinomas in pleomorphic adenoma were more often found in males (70.8%) and at the ages over 50 (43.8%). Histologic types were composed mostly of undifferentiated carcinoma (56.2%) and adenocarcinoma (37.5%). The prognosis of the carcinomas, especially the undifferentiated type, was generally poor; about 45% of the cases either experienced recurrence or died within five years. Electron microscopy on this undifferentiated carcinoma revealed characteristic filamentous structure in the carcinoma cells, resembling that observed in myoepithelial cells. It was assumed that the undifferentiated carcinoma cells were of myoepithelial origin.

Adenoma, Pleomorphic↗

PubMed2026

Pleomorphic Liposarcoma: Comprehensive Genomic Analysis of 39 Cases With Comparison to Other Genomically Complex Sarcomas.

Pleomorphic liposarcoma (PLPS) is an aggressive high-grade sarcoma that often shows diverse morphological features and can mimic high-grade undifferentiated pleomorphic sarcoma (UPS)/spindle cell sarcoma or myxofibrosarcoma (MFS), especially when pleomorphic lipoblasts are sparse. The molecular profile of PLPS is distinct from well differentiated/dedifferentiated liposarcoma and myxoid liposarcoma. In this study, we investigate 39 cases of PLPS by comprehensive genomic profiling, occurring in 32 patients with available molecular data. Cases were reviewed and morphologic parameters-lipoblastic component, UPS-like, and MFS-like areas were estimated. The genomic findings were collected and compared to UPS and MFS groups studied using the same platform. The cohort included 15 females and 17 males, with a median age of 56.5 (range, 34-78). The lower extremity (n = 17) was the most common site involved, followed by upper extremity (n = 5) and pelvis (n = 5). UPS-like and MFS-like patterns were the most common morphologic variants, ranging from 15% to 95% and 20% to 90%, respectively. TP53 (87%) and RB1 (51%) mutations and copy number alterations were the most common alterations seen, followed by ATRX (36%). Compared to UPS and MFS, TP53 and RB1 gene alterations were significantly more common in PLPS. Conversely, CDKN2A/B deletions were infrequent in PLPS. Survival analysis showed that MYC amplification was associated with significantly shorter overall survival in PLPS. Among histologic variants, CYSLTR2 alterations were found to be highest in cases with predominantly pleomorphic lipoblasts; additionally, strong correlations were found between gene alteration frequencies of MFS and MFS-like PLPS, and between UPS and UPS-like PLPS. RB1 allele-specific copy number analysis showed loss of heterozygosity in 82% of cases. Our cohort of PLPS showed a complex molecular landscape with distinct genetic alterations, histologic correlations, and clinical outcomes, highlighting its unique position among genomically complex sarcomas and providing insights that may inform future diagnostic and therapeutic approaches.

Humans↗

PubMed1985

The pleomorphic adenoma of salivary glands transplanted on athmymic mice. A lightmicroscopical and immunohistochemical investigation.

10 pleomorphic adenomas of the human parotid gland were transplanted on several groups of nude mice. For comparative reasons, 10 other pleomorphic adenomas, a neurinoma and a chordoma and transplants of squamous cell carcinomas and of normal salivary gland tissue were also analysed. In the primary tumours and in the transplants, the presence of keratin, carcinoembryonic antigen, tissue polypeptide antigen, lactoferrin, lysozyme, immunoglobulins, secretory component, amylase, fibronectin and of several lectin-receptors (PNA, WGA, HPA, Ulex europaeus) was sought. The immunohistological observations show that many of the features of a pleomorphic adenoma are constant under the conditions of transplantation. In the transplanted tumour, the same heterogeneity as in the primary tumours can be observed. Autoradiographic studies show little labelling with 3-H thymidine, which is in good accordance with the biological behaviour of the tumour. The distribution of fibronectin shows an interesting association with myoepithelial-like cells. Our results support the hypothesis that the histogenetic origin of the pleomorphic adenoma is a cell pool of the terminal ductal segment. A differentiation towards ductal cells (with production of secretory substances) and towards myoepithelial cells (associated with large amounts of basal membrane like substances) is observed.

Adenoma, Pleomorphic↗

PubMed1988

Phenotypic expression of human epidermal growth factor in foetal submandibular gland and pleomorphic adenoma of salivary gland.

The phenotypic expression of the human epidermal growth factor (EGF) was investigated immunohistochemically in human foetal submandibular glands from the 5th to 10th month of gestation, adult normal submandibular glands and 48 cases of pleomorphic adenomas. In foetal submandibular glands, both the terminal buds and primary ducts at the intermediate stage of gestation were positive for EGF, and in particular, the outer layer cells of primary ducts showed strong EGF-immunoreactivity. EGF-positive cells decreased as the gestational stage advanced and only ductal cells were weakly positive for EGF at the terminal stage of gestation. In the adult normal submandibular gland, weak immunoreactivity for EGF was restricted to ductal cells. However, 41 (86%) of the 48 pleomorphic adenomas had EGF-positive cells which were distributed among the ductal, chondroid and myxoid portion. No EGF-immunoreactivity was detected in the solid portion of pleomorphic adenomas. These results suggest that EGF may play an important role in the growth and differentiation of foetal cells as well as the proliferation of tumour cells in pleomorphic adenomas.

Adenoma, Pleomorphic↗

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↗

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↗

PubMed2000

Keratin 14 immunoreactive cells in pleomorphic adenomas and adenoid cystic carcinomas of salivary glands.

Our recent study of developing myoepithelial cells (MECs) in rat salivary glands demonstrated that developing MECs begin to express alpha-smooth muscle actin (alphaSMA) first and, thereafter, keratin 14. Therefore, it is unlikely that duct basal cells expressing keratin 14 alone are immature or undifferentiated MECs. In this study we carried out immunohistochemistry of pleomorphic adenomas and adenoid cystic carcinomas including normal salivary glands using monoclonal antibodies to keratin 14, smooth muscle proteins and keratin 19. The smooth muscle proteins examined included alphaSMA, h-caldesmon and h1-calponin; h1-calponin was observed in keratinocytes and nerve fibers, indicating that the protein is not specific to smooth muscle, whereas alphaSMA and h-caldesmon turned out to be highly specific markers for smooth muscle cells in normal tissues. In normal glands, MECs were positive for both keratin 14 and smooth muscle proteins (alphaSMA and h-caldesmon). Non-MEC cells were essentially devoid of smooth muscle proteins. Non-MEC duct basal cells expressed keratin 14 with or without keratin 19, and luminal cells keratin 19 with or without keratin 14. This suggests that the keratin 14-positive, smooth muscle proteins-negative duct basal cells are luminal cell progenitors. Luminal cells in tubular structures of both tumors were positive for keratin 19 with or without keratin 14. Nonluminal peripheral cells of pleomorphic adenomas were mostly positive for keratin 14, and a small fraction of them expressed smooth muscle proteins. Conversely, peripheral cells of adenoid cystic carcinomas were mostly positive for smooth muscle proteins, and some of them expressed keratin 14. These results strongly suggest (1) that the luminal cell progenitors transform into major constituents of pleomorphic adenoma cells with keratin 14 but not smooth muscle proteins, and (2) that the peripheral cells of adenoid cystic carcinoma are derived from undifferentiated MECs. Solid structures of pleomorphic adenomas were formed by proliferation of the peripheral cells. MECs were observed only occasionally in the periphery. Solid and cribriform structures of adenoid cystic carcinomas were formed by proliferation of the luminal cells. MECs were observed in the periphery and around the pseudocyst.

Actins↗

PubMed1999

Reconstruction of pleomorphic adenoma of the salivary glands in three-dimensional collagen gel matrix culture.

The morphogenesis of salivary gland pleomorphic adenoma was examined in vitro using three-dimensional (3-D) collagen gel culture. Pleomorphic adenoma cells were isolated from three parotid gland tumours and cultured as monolayers, after which they were subcultured in floating-collagen gel sandwiches. Cells cultured in both conditions were immunohistochemically characterized and compared using antibodies against various proteins representative of each histological component of salivary glands. Monolayers had myoepithelial characteristics, being positive for vimentin and alpha-smooth muscle actin. In collagen gels, however, the cells assembled in epithelial nests, showing an architecture similar to that of pleomorphic adenoma. The nests were composed of duct-lining epithelial cells that were positive for epithelial markers, surrounded by myoepithelial cells. Collagen gel culture induces multidirectional differentiation of adenoma cells, suggesting that pleomorphic adenomas originate from stem or reserve cells.

Actins↗

PubMed2006

Pleomorphic adenoma of the nasal septum and its relationship with Epstein-Barr virus.

OBJECTIVES: Pleomorphic adenoma is the most common benign tumor of the major salivary glands, especially of the parotid gland. It is much less common in the minor salivary glands of the oral cavity, and it rarely occurs in others sites in the head and neck. Even if virus involvement in salivary glands tumor has been many times discuted, the etiology of this tumor keeps being unknown. As compared to other nasal tumors, we tried to prove if Epstein-Barr virus (EBV) could be involved in the development of pleomorphic adenoma in this particular nasal localization. METHODS: Three cases of pleomorphic adenomas of the nasal septum (two women and a man in age of 23-59 years) were retrospectively studied. All had positive rate of EBV-related blood antibodies. All the patients had undergone endoscopic surgery to remove the complete tumor. We used hybridation technique in the search for EBV-DNA in the three tumors. RESULTS AND CONCLUSION: We had positive EBV-DNA detection in the tumor in one case, which seemed to prove relationship between pleomorphic adenoma and this virus. The literature concerning the subject is reviewed in order to explain EBV involvement in the development of such tumors in this particular localization.

Adenoma, Pleomorphic↗