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PubMedDate not supplied

A case of pleomorphic adenoma of the lung with multiple distant metastases--observations on its oncogene and tumor suppressor gene expression.

Pleomorphic adenoma of the lung is a rare neoplasm. Here we describe the first report on oncogenes and tumor suppressor genes in metastasizing pleomorphic adenoma of the lung. A 48-year-old Japanese woman presented with metastasizing pleomorphic adenoma in which both the primary lung tumor and metastatic lesions were composed of benign pleomorphic structures. The mechanism of the metastatic potential was examined by analyzing known oncogenes and tumor suppressor genes by DNA blot analysis and immunohistochemistry. No rearrangements amplifications or overexpressions of oncogenes, bcl-2, c-erbB-2, c-myc, L-myc, N-myc, Ha-ras and Ki-ras were found. In addition, immunohistochemical studies showed no aberrance in expressions of the tumor suppressor gene products, RB, p16 and p53 in the tumor. Some unknown mechanism(s) seems to be responsible for the aggressiveness of this metastasizing pleomorphic adenoma. This mechanism must be elucidated by studies on further case of this rare tumor.

Adenoma, Pleomorphic↗

PubMed1977

Pleomorphic carcinoma of the pancreas: an analysis of 15 cases.

Pleomorphic carcinoma of the pancreas is a well defined histopathological entity characterized by non-cohesive, sarcoma-like growth pattern, and bizarre mono- and multinucleated tumor giant cells with abundant eosinophilic cytoplasm. Fifteen cases are identified in autopsy files of the Department of Pathology, Washington University School of Medicine, which represent 7.1% of all the non-endocrine pancreatic malignancies found at autopsy. Pleomorphic carcinoma is comparable to pancreatic adenocarcinoma in clinical features such as age, sex, and presenting symptoms except that it is more likely to occur in the body and tail of the pancreas, metastases invariably develop, hematogenous spread is more common, and the median survival is worse. Pleomorphic carcinoma could be distinguished from the pancreatic tumors that resemble giant cell tumor of the bone. Differential diagnostic features between it and amelanotic melanoma, hepatocellular carcinoma, choriocarcinoma, pleomorphic liposarcoma, pleomorphic rhabdomyosarcoma, fibroxanthosarcoma, poorly differentiated epidermoid carcinoma, and giant cell carcinomas of the lung and thyroid are discussed.

Adenocarcinoma↗

PubMed1978

Ultrastructural observations in pleomorphic liposarcoma.

An ultrastructural study of pleomorphic liposarcoma with an unusual clinical presentation is described. A 69-year-old Caucasian female presented with recurrent superficial phlebitis of left leg, which responded only partially to conventional therapy. Following investigations, a mass was excised. Diagnosis of pleomorphic liposarcoma was made on microscopic examination. Numerous lipid droplets in the cytoplasm and often within intranuclear extensions of cytoplasm were seen on oil red O stain of frozen sections. Ultrastructural features are quite distinctive. The cells varied from small to often large pleomorphic cells with numerous lipid spaces without limiting membrane, large pleomorphic nuclei, and an abundance of cytoplasmic organelles. Centrioles were very prominent, in close proximity to nuclei, and collections of autophagocytic inclusions. Intercellular collagen was immature and scant. These features are compared to ultrastructural features of malignant fibrous histiocytoma, pleomorphic rhabdomyosarcoma, and cardiac myxoma, indicating that ultrastructural features are distinctive and help differentiate similar soft tissue tumors.

Aged↗

PubMed1992

Pleomorphic lobular carcinoma of the breast: an aggressive tumor showing apocrine differentiation.

Pleomorphic lobular carcinoma of the breast is a recently recognized subtype of invasive lobular carcinoma (ILC). Cytologic features are pleomorphic to a degree that contrasts with the cytologic uniformity of classic ILC. It is this feature that simultaneously gives its name to the tumor and highlights the difficulty of identifying it correctly and distinguishing it from ductal carcinoma. In our series of 10 cases, six tumors also contained lobular carcinoma in situ. Nodal metastases were typically sinusoidal. All tumors showed the dissociated, linear, and single file pattern of classic ILC, together with a targetoid distribution. Intracytoplasmic lumina were present in 50% of the tumors. An eosinophilic, slightly granular cytoplasm suggests the possibility of apocrine differentiation, a suggestion derived also from the frequent presence of foamy cells, a cell type previously identified in histiocytoid lobular carcinoma and shown to have apocrine features. The GCDFP-15 apocrine marker was positive in all 10 tumors, while all control ILCs were negative, confirming the presence of apocrine differentiation in pleomorphic lobular carcinoma. Six of 10 patients died within 42 months of diagnosis. Three other patients developed recurrence or distant metastases at short intervals. Pleomorphic lobular carcinoma is a very aggressive tumor. This behavior is perhaps predictable on the basis of tumor size at presentation and the frequency of nodal metastases. Since grading of lobular carcinoma is difficult, recognition of the pleomorphic subtype is useful in identifying a lethal variant.

Aged↗

PubMedDate not supplied

Malignant degeneration of pleomorphic adenoma--clinical implications.

INTRODUCTION: The incidence of carcinoma arising in a pleomorphic adenoma is reportedly between 1.4% and 6.3%. Malignant degeneration is often associated with a prolonged history of untreated or recurrent pleomorphic adenoma. MATERIALS AND METHODS: Two patients with malignant parotid carcinoma that arose from benign pleomorphic adenoma are reviewed. RESULTS: Both patients exhibited a prolonged history of pleomorphic adenoma apparently persistent after initial inadequate surgery. Surgeries were performed 37 and 12 years before development of malignancy. DISCUSSION: The phenomenon of malignant carcinoma arising from benign pleomorphic adenoma is an important issue. The occurrence of these malignant carcinomas emphasizes that aggressive treatment of primary and recurrent mixed tumors is necessary.

Adenocarcinoma↗

PubMed2005

Pleomorphic mammalian tumor-derived bacteria self-organize as multicellular mammalian eukaryotic-like organisms: morphogenetic properties in vitro, possible origins, and possible roles in mammalian 'tumor ecologies'.

Highly pleomorphic bacteria have regularly been isolated from mammalian tumors and leukemic bloods. Here, it is shown that highly pleomorphic, cell-wall deficient bacteria derived from a mammalian tumor self-organize in vitro into mammalian tissue-like morphogenetic patterns consisting of multicellular tissue-like sheets and capillary-like networks. It is proposed that these pleomorphic mammalian tumor-derived (MTD) bacteria, during morphogenesis, express mammalian tissue morphogenesis-related genes that were acquired through eukaryote-to-prokaryote DNA transfer. Similar pleomorphic MTD bacteria might play important roles as symbiotic multicellular mammalian eukaryotic-like organisms in mammalian 'tumor ecologies' that include malignant and nonmalignant mammalian eukaryotic cells. From a mammalian tumor ecology perspective, eradication of tumors in some mammalian hosts may depend upon the elimination of pleomorphic MTD bacteria self-organized as symbiotic multicellular mammalian eukaryotic-like organisms. Further investigations of the extraordinary mammalian eukaryotic-like multicellularity of these bacteria may yield fundamental insights into the evolution of multicellularity and multicellular development and may challenge basic assumptions regarding cellular evolution.

Animals↗

PubMed2003

Pleomorphic lipoma of the orbit: a case series and review of literature.

OBJECTIVE: Pleomorphic lipomas are rare benign tumors that can resemble a variety of malignant soft tissue tumors on histologic examination. Six cases of patients with orbital pleomorphic lipoma, one of which was proven to be bilateral, are presented. DESIGN: Retrospective, noncomparative, interventional case series with clinicopathologic correlation. METHODS: Clinical and histologic review of 6 patients with pleomorphic lipomas of the orbit and histologic review of fat from 22 exenteration specimens and 20 other orbital procedures. MAIN OUTCOME MEASURES: Evidence of histologic abnormalities in histologic specimens. RESULTS: Pleomorphic spindle cells and multinucleated cells with nuclei arranged in a floret-like pattern were present in 7 specimens from 6 patients presenting with a clinical diagnosis of orbital fat prolapse, but there were no similar cell types present in the adipose tissue of 22 exenteration or 20 other orbital specimens. CONCLUSION: Pleomorphic lipoma may arise in the orbit, presenting as what was hitherto considered to be age-related epibulbar prolapse of orbital fat.

Aged↗

PubMed1991

Pleomorphic adenoma of the external auditory canal in Japan, with a case report.

A rare case of a 51-year-old female with a pleomorphic adenoma, measuring 0.9 x 0.7 x 0.6 (cm3), originating from the right external auditory canal (EAC), was reported. The authors discussed the 7 reported cases of EAC pleomorphic adenoma in Japan, comparing them with pleomorphic adenomas occurring in the nasal cavity and the parotid gland. It is currently too early to conclude that pleomorphic adenoma in the EAC does not tend to recur or shows a marked tendency toward canceration. The best possible treatment for EAC pleomorphic adenoma at present seems to be, as in cases of tumors in other sites, surgical resection together with removal of a sufficient range of surrounding normal tissue, followed by careful long-term postoperative observation of the clinical course.

Adolescent↗

PubMed2001

Pleomorphic liposarcoma: a clinicopathologic analysis of 19 cases.

Pleomorphic liposarcoma is a variant of liposarcoma defined morphologically by the presence of pleomorphic lipoblasts. Because of its rarity, there are limited studies with long-term follow-up information. Nineteen pleomorphic liposarcomas were studied. Unequivocal pleomorphic lipoblasts were required for inclusion. In each case, the following features were noted: tumor site; tumor size; tumor depth; predominant histologic pattern (epithelioid or malignant fibrous histiocytoma [MFH]-like); extent of necrosis (absent, less than 15%, or at least 15%); mitotic counts; treatment and clinical follow-up. Patients were 11 females and 8 males, aged 33-87 years (mean, 64.5 y; median, 70 y). Tumors involved the extremities (13 patients: intramuscular in 10, subcutaneous in 2, depth unknown in 1), retroperitoneum (4 patients), mediastinum (1 patient), and paratesticular region (1 patient). Size ranged from 4.5--31 cm (mean, 11.9 cm; median, 12.0 cm). Predominant pattern was epithelioid in 7 and MFH-like in 12. Necrosis was present in 15 (79%) and was extensive (36 15%) in 14 patients. Mitotic counts ranged from 0.2--3.4/10 high-power fields (mean, 1.4; median, 1.4) by the average-count method and from 1--6/10 high power fields by the highest count method (mean, 2.9; median, 3.0). All patients were treated surgically; 10 patients received adjuvant chemotherapy and/or radiation therapy. On follow-up of 18 patients (range, 2--129 mo; mean, 35.4 mo; median, 23 mo) nine (50%) were dead of disease (range, 2--48 mo; mean, 20.1 mo; median, 12 mo), one died of other causes 2 months after diagnosis, two were alive with disease, five were disease free, and one was alive at 129 months (tumor status unknown). Five had recurrences (range, 3--28 mo; mean, 14.4 mo; median, 8 mo), and four of five (80%) with recurrences were dead of disease. Metastases developed in eight patients (range, 4--48 mo; mean, 19.5 mo; median, 11.5 mo), most commonly to the lungs. In conclusion, pleomorphic liposarcoma is a rare tumor of adulthood that occurs most commonly in the deep, soft tissues of the extremities. It behaves as a high-grade sarcoma that frequently metastasizes, most commonly to the lungs. Although this tumor has a wide range of histologic appearances, no clinical or pathologic feature is predictive of a more aggressive clinical course.

Adult↗

PubMed2000

Immunohistochemical analysis of pleomorphic lobular carcinoma: higher expression of p53 and chromogranin and lower expression of ER and PgR.

AIMS: Pleomorphic lobular carcinoma of the breast is a histological variant of infiltrating lobular carcinoma with a poor prognosis. The aim of this study is to investigate the immunohistochemical profile of this distinctive breast carcinoma in comparison with the classical type. The expression of cytokeratin, epithelial membrane antigen, gross cystic disease fluid protein-15, chromogranin, oestrogen and progesterone receptors and p53 oncoprotein was investigated to examine whether the expression of these markers correlates with the aggressiveness of this variant. METHODS AND RESULTS: Sections from 10 cases of pleomorphic lobular carcinomas were reviewed and examined for the expression of cytokeratin of high and low molecular weight, epithelial membrane antigen (EMA), gross cystic disease fluid protein-15 (GCDFP-15), chromogranin, oestrogen (ER) and progesterone receptors (PgR), and p53 oncoprotein. Immunohistochemical staining was performed on paraffin wax embedded sections. Ten cases of classical lobular carcinomas were used for comparison. A semiquantitative count of the percentage of positive tumour cells was recorded. Pleomorphic lobular carcinomas have most of the characteristic histological features of the classical type but have nuclear anaplasia and abundant granular cytoplasm. Clinically they exhibited poor prognosis and a high frequency of nodal metastases. All of the pleomorphic lobular carcinomas expressed low and high molecular weight keratin, EMA, and GCDFP-15, eight cases expressed nuclear p53 at a range between 10% and 45%. All cases expressed chromogranin (3-5%). ER and PgR were weakly positive in two cases and negative in eight cases. Classical infiltrating lobular carcinomas were all positive for cytokeratin, EMA, ER and PgR and negative for GCDFP-15. Only five cases of classical lobular carcinoma expressed p53 positivity with up to 5% nuclear staining while chromogranin showed less expression (1-2%). CONCLUSION: Pleomorphic lobular carcinoma exhibits distinct cellular features with apocrine differentiation, higher expression of chromogranin and p53 protein and lower ER and PgR in comparison with classical lobular carcinomas. Determination of p53 overexpression and reduced or absent expression of ER and PgR may help predict the behaviour of this variant of lobular carcinoma.

Aged↗

PubMed2003

The division of pleomorphic plastids with multiple FtsZ rings in tobacco BY-2 cells.

Plastids, an essential group of plant cellular organelles, proliferate by division to maintain continuity through cell lineages in plants. In recent years, it was revealed that the bacterial cell division protein FtsZ is encoded in the nuclear genome of plant cells, and plays a major role in the plastid division process forming a ring along the center of plastids. Although the best-characterized type of plastid division so far is the division with a single FtsZ ring at the plastid midpoint, it was recently reported that in some plant organs and tissues, plastids are pleomorphic and form multiple FtsZ rings. However, the pleomorphic plastid division mechanism, such as the formation of multiple FtsZ rings, the constriction of plastids and the behavior of plastid (pt) nucleoids, remains totally unclear. To elucidate these points, we used the cultured cell line, tobacco (Nicotiana tabacum L.) Bright Yellow-2, in which plastids are pleomorphic and show dynamic morphological changes during culture. As a result, it was revealed that as the plastid elongates from an ellipsoid shape to a string shape after medium renewal, FtsZ rings are multiplied almost orderly and perpendicularly to the long axis of plastids. Active DNA synthesis of pt nucleoids is induced by medium transfer, and the division and the distribution of pt nucleoids occur along with plastid elongation. Although it was thought that the plastid divides with simultaneous multiple constrictions at all the FtsZ ring sites, giving rise to many small plastids, we found that the plastids generally divide constricting at only one FtsZ ring site. Moreover, using electron microscopy, we revealed that plastid-dividing (PD) rings are observed only at the constriction site, and not at swollen regions. These results indicate that in the pleomorphic plastid division with multiple FtsZ rings, the formation of PD rings occurs at a limited FtsZ ring site for one division. Multiplied FtsZ rings seem to localize in advance at the expected sites of division, and the formation of a PD ring at each FtsZ ring site occurs in a certain order, not simultaneously. Based on these results, a novel model for the pleomorphic plastid division with multiple FtsZ rings is proposed.

Arabidopsis Proteins↗

PubMed2002

Clinical, histopathologic, and biologic features of pleomorphic lobular (ductal-lobular) carcinoma in situ of the breast: a report of 24 cases.

We reviewed 10 cases of pleomorphic lobular (ductal lobular) carcinoma in situ (PL/DLCIS) of the breast and compared them with 14 cases of pleomorphic lobular carcinoma in situ (PLCIS) found in association with invasive pleomorphic lobular carcinoma. The histologic features; immunohistochemical staining for estrogen receptors (ERs), p53, Ki67, E-cadherin, and gross cystic disease fluid protein-15 (GCDFP-15); and results of fluorescence in situ hybridization for HER-2/neu gene amplification were evaluated in all 24 cases. Histologically, PL/DLCIS cells were similar to those of PLCIS with invasion in that they were discohesive and medium to large in size with moderate to marked nuclear pleomorphism, small to prominent nucleoli, and moderate to abundant eosinophilic or vacuolated cytoplasm. In both groups, central necrosis was present in a small number of cases, and classic LCIS coexisted with the in situ lesion in less than half of the cases; in situ carcinomas were positive for ERs in 23 (100%) of 23 cases, p53 in 6 (25%) of 24 cases, and GCDFP-15 in 14 (74%) of 19 cases. The percentage of Ki67-positive tumor nuclei indicated moderate to high (more than 20%) proliferative activity in 8 (47%) of 17 cases. Immunostaining for E-cadherin was negative in all 24 cases. HER-2/neu gene amplification was observed in 1 (4%) of 23 cases. In cases with associated invasion, PLCIS had cytologic features and immunostaining patterns similar to those of the invasive pleomorphic component. Seven of the 10 patients who had PL/DLCIS without invasion underwent lumpectomy or simple mastectomy. Six of these patients had no evidence of disease in follow-up periods ranging from 4 to 32 months; the seventh patient developed recurrent disease 12 months after undergoing lumpectomy. We conclude that the cytologic features and biomarker expression profile of PL/DLCIS are similar to those of PLCIS with invasion but somewhat different from those of classic LCIS and ductal carcinoma in situ. Long-term follow-up studies are needed to further define the natural history of PL/DLCIS and its optimal management.

Adult↗

PubMed2005

Pleomorphic pancreatic endocrine neoplasms: a variant commonly confused with adenocarcinoma.

Most pancreatic endocrine neoplasms (PENs) have distinctive endocrine growth patterns and uniform nuclear morphology; they are regarded as relatively low-grade tumors. Significant nuclear pleomorphism is a feature that may raise concerns about aggressive behavior or even obscure the endocrine nature of the neoplasm. Eight PENs exhibiting marked nuclear pleomorphism (>20% of the tumor cells) were identified during a review of 136 PENs (5.9%) from the pathology files of Memorial Sloan-Kettering Cancer Center. The histologic, immunohistochemical, ultrastructural (4 cases), and clinical features were reviewed. There were 6 males and 2 females ranging from 30 to 69 years (mean, 55 years). The tumors averaged 5.8 cm (range, 1.5-14 cm). Six tumors (75%) were initially misdiagnosed in 5 cases as adenocarcinoma and in one as solid-pseudopapillary tumor; in 2 cases, the misdiagnosis was based on fine needle aspiration cytology and in 4 on histologic examination. The architectural features of the tumors resembled those of other PENs, but the nuclei were markedly enlarged, irregularly shaped, and hyperchromatic, with frequent bizarre forms. Cells with pleomorphic nuclei also generally had abundant cytoplasm, sometimes with large perinuclear glassy inclusions. The mitotic rate was not elevated compared with other PENs, averaging 1.9 (range, 0-7) per 50 high power fields. Immunohistochemical findings were (number positive/number stained): chromogranin (8 of 8), synaptophysin (7 of 8), progesterone receptor (4 of 7), CD99 (2 of 5), S-100 protein (3 of 7), and p53 (0 of 6). Scattered cells expressed peptide hormones in a minority of cases. By electron microscopy, abundant dense core granules were identified, in some cases embedded within perinuclear arrays of intermediate filaments. Six patients underwent curative resection; at follow-up, 4 were free of disease at 11, 13, 30, 112 months (mean, 42 months), 1 developed liver metastases at 77 months and was alive with disease at 94 months, and 1 was lost to follow-up. Two patients had unresectable tumors and were alive with disease at 10 and 78 months. Striking nuclear pleomorphism may occur in otherwise typical PENs and commonly causes difficulties in the distinction from adenocarcinoma. There does not appear to be prognostic significance to these nuclear changes, and the morphologic features of pleomorphic PENs otherwise resemble those of their conventional counterparts.

Adenocarcinoma↗

PubMed2006

Pleomorphic giant cell adenocarcinoma of the prostate: report of 6 cases.

Pleomorphic tumors with giant cells have been described in a variety of primary sites. However, only a few cases have been described among prostatic carcinomas with only 1 on diagnostic biopsy material. Five cases were retrieved from the consultation files of one of the authors. One of the cases was retrieved from the surgical pathology files at our institute. Patient ranged in age from 59 to 76 years (mean=65.8 y). The diagnosis was made on needle biopsy (n=3), urethral biopsy (n=1), transurethral resection (n=1), or radical prostatectomy (n=1). In all cases, giant, bizarre, anaplastic cells were present. In 4 of the cases, marked pleomorphism occupied 5% of the specimen, with 20% and 70% bizarre giant cells in the other 2 cases. In one case, the bizarre cells had atypical mitotic figures, with other cases showing no mitoses in the markedly pleomorphic cells. In addition to the pleomorphic giant cell component, multiple coexistent histologic components were seen including Gleason score 9 conventional prostate cancer (n=6), small cell carcinoma (n=1), squamous carcinoma (n=1), and prominent ductal adenocarcinoma differentiation with intraductal spread (n=1). Immunohistochemically, 4 cases were for negative for prostate-specific antigen in the giant cells, 1 had 5% staining, and the other had 50% positivity in the giant cells. Staining for prostate-specific antigen in the conventional prostate carcinoma component was 1%, 5%, 20%, 50%, 100%, and 100%. The bizarre giant cells were strongly positive for cytokeratins AE1/AE3 and/or Cam 5.2 (n=3). Two cases had a history of conventional prostate cancer 4 years before the giant cell component, 1 treated with Lupron and the other with radiation. Follow-up after diagnosis of the giant cell component: Case 1: dead in 1 year of disease; Case 2: progressive metastases in 2 years; Case 3: alive at 1 year with disease; Case 4: large perineal recurrence after brachytherapy at 3 years; Case 5: radical prostatectomy with extraprostatic extension and seminal vesicle invasion; and Case 6: alive at 3 months, free of disease. Conventional prostate cancer, even when very high grade, typically consists of cells with relatively uniform nuclei. Our study expands the histology described in prostate cancer to include in very rare cases with prominent pleomorphism and bizarre giant cells. This giant cell component heralds a particularly aggressive clinical outcome.

Adenocarcinoma↗

PubMed2006

Pleomorphic basal cell carcinoma: case reports and review.

Pleomorphic basal cell carcinoma is a pathologic variant of basal cell carcinoma characterized by the presence of atypical-appearing, mononuclear or multinucleated giant cells. Including our 3 patients, a total of 52 pleomorphic basal cell carcinomas have been described in 48 individuals. The tumors usually present as a nodule on the head or neck. The nuclei of the giant tumor cells are irregularly shaped, hyperchromatic, and 2 to 10 times larger than the nuclei of the surrounding cancer cells. Atypical mitoses may be present. The pathogenesis of pleomorphic basal cell carcinoma remains to be determined; however, investigations utilizing electron microscopy, immunohistochemistry, image analysis, and flow cytometry have provided additional insight regarding the features of the giant tumor cells and the etiology of this cancer. All of these tumors are aneuploid. Although these aneuploid tumors have alarming microscopic features, their clinical course is similar to that of basal cell carcinomas without pleomorphic giant tumor cells. Therefore, appropriate therapy to ensure adequate treatment of the tumor is recommended. Our patients' pleomorphic basal cell carcinomas were successfully treated by excision using the Mohs micrographic surgical technique.

Aged↗

PubMed1984

Pleomorphism among murine tissue-associated gp70s.

The gp70s isolated from normal mouse tissues by radioimmune precipitation and SDS-polyacrylamide gel electrophoresis (SDS-PAGE) were shown to be highly pleomorphic. Their apparent molecular weights calculated from SDS-PAGE ranged from 75000 for thymus gp70 to 65000 for epididymal secretion gp70. Differences in the Mr of tissue-associated gp70s were confirmed by double-label co-electrophoresis studies. In addition, a high degree of primary structural pleomorphism among tissue-associated gp70s was demonstrated using two-dimensional tryptic peptide fingerprint analysis. These studies showed that most of the conserved peptides of tissue-associated gp70s were also common to xenotropic murine leukaemia virus (MuLV) gp70s. Thus, tissue-associated gp70s are probably encoded by endogenous xenotropic MuLV env genes or gene fragments. Tissue-associated gp70s also showed a very high level of primary structural pleomorphism. These phenomena were observed for gp70s derived from the tissues of several strains of mice. Tissue-associated gp70 pleomorphism may arise as a consequence of at least two simultaneously operating mechanisms. First, the expression of pleomorphic forms of gp70s on murine tissues may be regulated by mechanisms that also determine the differentiated state of the tissues. Second, endogenous xenotropic env genes may be modified by recombinational or mutational events among these genes, or among cellular genes that regulate the expression of endogenous proviral genes.

Animals↗

PubMed1997

Pleomorphic hyalinizing angiectatic tumor of soft parts: immunohistochemical case study shows cellular composition by CD34+ fibroblasts and factor XIIIa+ dendrophages.

We report immunomorphologic observations on a pleomorphic hyalinizing angiectatic tumor of soft parts (PHAT), a rare tumor recently described by Smith, Fisher, and Weiss. A 2 cm skin-covered, grossly lobulated, firm, yellow-tan, focally hemorrhagic tumor was excised from the dorsum of a 59-year-old woman's right foot. It infiltrated dermis and subcutis and entrapped skin adnexae. The tumor microscopically resembled both a pleomorphic malignant fibrous histiocytoma and a neurilemoma with fascicular spindle cell pattern, pleomorphic tumor giant cells, and focal congeries of ectatic, fibrinous, and slightly hyalinized vessels. Tumour cells produced abundant reticulin but collagenous sclerosis was minimal. Mast cells were numerous. Pleomorphic cells, some phagocytic, had intranuclear vacuolar inclusions and many cells had large pale cytoplasmic globular inclusions. Most tumor cells expressed vimentin and CD34, including pleomorphic cells. Factor XIIIa stained focally 20-40% of the spindle cells. S-100 and cytokeratin were negative and actin and desmin stained only vessel myopericytes. The Ki 67 index was 3% with mostly large CD34+ cells and a few smaller FXIIIa+ cells in the cycling fraction. We conclude that PHAT is a fibrohistiocytic tumor probably derived from proliferating microvascular CD34+ dendritic cells and FXIIIa+ dendrophage cell subsets. Possible interactions between these cell types deserve further study in PHAT and other fibrohistiocytic tumors.

Antigens, CD34↗

PubMed1975

Characterization of an antibody directed against a surface component of normal and pleomorphic cells of Streptococcus sanguis.

Whole cells of Streptococcus sanguis were utilized as an immunoadsorbent to purify large quantities of an antibody (S1) directed against a cell surface component. The S-1 antibody was isolated from antisera to normal (N) and pleomorphic (O) cells by a similar adsorption-elution procedure. The S-1 antibody isolated from antisera to N cells reacted in gel diffusion in identify with the S-1 antibody to O cells, indicating that the antigen which binds S-1 antibody (Ag-1) may not be radically altered when cells become pleomorphic. The S-1 antibodies directed against both N and O cells had restricted heterogeneity, indicating that for both types of cell Ag-1 may have a simple repeating structure. However, N cells were agglutinated to a greater extent by S-1 antibody than O cells. In addition the distribution of the bound S-1 antibody became altered as the cells became pleomorphic. Utilizing the technique of indirect immunofluorescence we observed that the S-1 antibody was distributed evenly on the surface of N cells. As the cells became pleomorphic, the antibody appeared to bind preferentially at the cell poles (capping). Later, as the cells became more grossly deformed, additional bands of immunofluorescence appeared to bisect the cells. Electron microscopic analysis indicated that the bound antibody was not associated with septal notches. The results suggest that the arrangement rather than the immunological properties of Ag-1 became altered as cells became pleomorphic.

Agglutination↗