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Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Immunohistochemistry for the histiocyte antigens CD68, L1, factor XIIIa, and S100 protein was performed on 19 cases of angiomatoid malignant fibrous histiocytoma (MFH) and for keratin, leukocyte common antigen, factor VIII-related antigen, muramidase, and desmin on six of these cases. Nine of 19 cases expressed the histiocyte differentiation antigen CD68, and in three cases expression was seen in greater than 90% of cells. Of the 19 cases studied, three contained rare S100-positive tumor cells, and two expressed factor XIIIa within tumor cells. In three of the six cases, rare desmin-positive tumor cells were identified. The neoplastic cells did not express the other antigens studied. CD68 was not detected in any of 12 cases of storiform-pleomorphic and myxoid MFH or in any of 24 cases of normal tissues or nonfibrohistiocytic mesenchymal tumors except for granular cell tumors. These results indicate that either the cells of angiomatoid MFH differentiate along lines of a tissue macrophage or alternatively, and perhaps more likely, are mesenchymal tumors with a phenotypic alteration, paralleling an enhanced capacity for phagocytosis and acquisition of lysosomes. In either event, the immunophenotype contrasts with conventional MFH and provides another independent set of observations in support of a separation of angiomatoid from conventional MFH.
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PMID:Evaluation of CD68 and other histiocytic antigens in angiomatoid malignant fibrous histiocytoma. 131 23

Neurofibromas, schwannomas, and neurotized melanocytic nevi may closely resemble one another at the light microscopic level. We studied 10 neurofibromas, 10 schwannomas, and 10 partially neurotized melanocytic nevi immunohistochemically using an antibody directed against factor XIIIa to determine if this antibody might provide a useful method of differentiating these lesions. The cases were also stained with S100 protein. All of the neurofibromas stained intensely for factor XIIIa. The proportion of cells staining within the tumors varied from 30% to 70%. In contrast, none of the schwannomas and neurotized nevi studied demonstrated staining of tumor cells with this antibody. S100 protein was expressed by 100% of neurofibromas, schwannomas, and melanocytic nevi. Our findings suggest that factor XIIIa may provide a reliable and practical means of differentiating cutaneous neurofibromas from neurotized nevi and cutaneous schwannomas. Distinguishing between these different tumor types may be important in some clinical situations, particularly with respect to rendering a diagnosis of von Recklinghausen's neurofibromatosis. The differences in the immunohistochemical profiles of neurofibromas and neurotized nevi support the concept that these tumors are histogenetically distinct, despite their similar histologic appearances.
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PMID:Immunohistochemical demonstration of factor XIIIa expression in neurofibromas. A practical means of differentiating these tumors from neurotized melanocytic nevi and schwannomas. 197 68

We present a case of multiple benign spindle cell tumors of the jejunum in a patient with von Recklinghausen's neurofibromatosis and describe the light-microscopic, immunohistochemical, and ultrastructural features of these lesions. Two small spindle cell nodules were located in the region of Auerbach's myenteric plexus and a third larger tumor produced a subserosal mass. The immunohistochemical profile of these tumors revealed that they were actin and S100-protein negative but positive for neuron-specific enolase. At the ultrastructural level, the tumors recapitulated features of Auerbach's plexus. These lesions are similar to previously described gastrointestinal autonomic nerve tumors, and we propose that this may be the site of origin of enteric stromal tumors in von Recklinghausen's neurofibromatosis.
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PMID:Auerbach's myenteric plexus. A possible site of origin for gastrointestinal stromal tumors in von Recklinghausen's neurofibromatosis. 169 3

Four new cases of ectopic hamartomatous thymoma are presented. The tumor occurred either superficially or deep in the area of the sternoclavicular joint and consisted of solid islands of squamous epithelium which blended with spindled cells. Cysts lined by squamous epithelium, small glands, and fat also occurred in variable amounts. Both the spindled and epithelial regions of the tumor expressed keratin and muscle actin, but neither desmin nor S100 protein. The tumor probably originates from thymic anlage associated with the third pharyngeal pouch (thymus III), although origin from other structures such as thymus IV and the cervical sinus of His are discussed. Our experience indicates that the large size and extreme cellularity of the spindled portion of some tumors may result in the mistaken diagnosis of sarcoma.
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PMID:Ectopic hamartomatous thymoma: clinicopathologic, immunohistochemical, and histogenetic considerations in four new cases. 169 94

We examined the immunohistochemical profile of 21 granular cell tumors (GCTs) and a single clinically malignant GCT using a panel of commercially available antibodies. All cases showed diffuse cytoplasmic and nuclear staining for S100 protein. Fourteen cases stained for myelin basic protein, Leu-7, or both. Immunostains for neurofilament protein and glial fibrillary acidic protein were negative in all cases. Stains for cathepsin B and alpha 1-antichymotrypsin were positive in 21 and 15 cases, respectively. Cathepsin-B reactivity may reflect autodigestion of myelin, while the presence of alpha 1-antichymotrypsin is less specific and may be related to cellular production of this product or to nonspecific uptake of alpha 1-antichymotrypsin in serum during the formation of phagolysosomes. All tumors expressed vimentin, often in a distinctive peripheral cytoplasmic pattern. Focal desmin staining was seen in three separate specimens from the patients with the malignant GCT, but this tumor also expressed S100 protein, myelin basic protein, and Leu-7 and did not stain for muscle-specific actin. The desmin reactivity in this single case probably represents non-specific staining rather than myogenous differentiation, since the reactivity to other nerve sheath markers shows histogenetic similarity with the benign GCTs. These findings support a Schwann cell origin for nongingival GCTs and illustrate a useful panel of commercially available antibodies to diagnose these distinctive tumors.
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PMID:Granular cell tumor. Immunohistochemical analysis of 21 benign tumors and one malignant tumor. 169 54

Glomus tumors and hemangiopericytomas have traditionally been described as neoplasms of pericytes. Ultrastructurally, smooth muscle features have been identified in the cells of the glomus tumor, while the cells of the hemangiopericytoma have been described as more closely resembling normal pericytes. Immunocytochemical studies were performed to demonstrate the immunophenotype of these two tumors and to particularly evaluate expression of muscle-specific actin and desmin. Using the avidin-biotin immunoperoxidase method, formalin-fixed, paraffin-embedded tissue from 16 glomus tumors and 11 hemangiopericytomas was evaluated for the presence of vimentin, low-molecular-weight cytokeratins (35 beta H11), muscle actins (HHF35), desmin (clone 33), S100 protein, nerve growth factor receptor (NGFR5), myelin-associated glycoprotein (CD57), Factor VIII-related antigen, and Ulex lectin. Muscle actins were found in 14 of 16 tumors, and desmin was found in three of 16 of the glomus tumors. None of the 11 hemangiopericytomas expressed either desmin or muscle actins. Variable numbers of both tumors were positive with antibodies to CD57, with the nerve growth factor receptor, and with antibodies to S100 protein. In conclusion, these studies provide immunocytochemical evidence of smooth muscle differentiation in glomus tumors. Although muscle differentiation has been identified in the normal pericyte by expression of muscle-specific actin (HHF35), we find no evidence for analogous differentiation in the population of cells comprising hemangiopericytomas.
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PMID:The immunophenotype of hemangiopericytomas and glomus tumors, with special reference to muscle protein expression: an immunohistochemical study and review of the literature. 170 1

Surgical specimens of 64 adrenal PCCs were investigated by conventional histology, immunocytochemistry and DNA-cytophotometry. Tumour weights of more than 200 g were recorded for each of the 6 malignant, but for only one of the 58 clinically benign neoplasms. Increased mitotic activity (greater than 5 mitoses/10 HPF) was, apart from one benign lesion, only seen among malignomas. Immunocytochemically, all malignomas were entirely devoid of S100-positive sustentacular cells and, as compared to benign PCCs, showed reduced expression rates of different neuropeptides. Upon cytophotometry, only 5/43 tumours exhibited euploid DNA histograms, all these cases belonging to the group of benign PCC. According to these findings, morphology does not enable a definite prediction of the clinical course of individual PCC cases, but renders the definition of risk groups possible. A benign diagnosis can be made in multihormonal euploid tumours weighing less than 200 g. In larger neoplasms and in cases lacking sustentacular cells and showing increased mitotic activity, an unfavourable prognosis is to be suspected and the same therapeutic procedures should be applied as for tumours in which malignancy is evident in metastatic growth.
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PMID:[Histology, immunocytochemistry and DNA cytophotometry of adrenal glandpheochromocytoma (PCC)--a morphologic clinal study of 64 tumors]. 170 5

The application of immunohistochemical markers against epithelial antigens has proved useful for studying tumor differentiation and in aiding tumor diagnosis. However, the reactivity of various epithelial markers with poorly differentiated carcinomas (the situation in which they are most often used) has not been well established. As a result, it is unclear how negative results should be interpreted and how often more than one antibody may be needed to document the epithelial nature of poorly differentiated neoplasms. We studied 98 poorly differentiated epithelial tumors with AE1, CAM 5.2, and EMA to assess the use of these markers in their diagnosis. Both CAM 5.2 and EMA provided support for epithelial differentiation in 71% (70/98) of the cases, while AE1 stained 50% (49/98) of the tumors; CAM 5.2 was the single most useful marker in the subset of poorly differentiated neuroendocrine carcinomas, staining 20 (77%) of 26 tumors. Use of these markers in pairs increased the recognition of epithelial differentiation (at least one marker showing positive staining) as follows: AE1/CAM 5.2, 80% (78/98); AE1/EMA, 87% (85/98); and CAM 5.2/EMA, 99% (97/98). Thirty carcinomas stained with all three markers, 34 with two markers, and in 34 cases only one antibody supported epithelial differentiation. Twelve (21%) of 58 tumors showed evidence of S100 reactivity. None of the 71 cases to which PD7 was applied showed staining This study indicates that poorly differentiated carcinomas are heterogeneous in their expression of antigens recognized by AE1, CAM 5.2, and EMA. Moreover, these results quantitate the probability of reactivity with poorly differentiated carcinomas for each marker and support the use of one or more antibodies in a "backup" panel when a negative result is obtained with a single antibody and the diagnosis of carcinoma is still suspected.
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PMID:Heterogeneity of epithelial marker expression in routinely processed, poorly differentiated carcinomas. 171 Jan

Two cases of polymorphous low-grade adenocarcinoma of the papillary type, from minor salivary glands were studied by light microscopy and immunohistochemistry. One case exhibited a predominance of the papillary pattern, whereas the other presented the following patterns of histological appearance: papillary, solid, pseudocystic and tubular. Utilizing the peroxidase-antiperoxidase (PAP) method, the intermediate filament vimentin, keratin and S100 protein were observed in tumor cells. The immunohistochemical analysis revealed two types of neoplastic cells: myoepithelial and luminal.
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PMID:[Low-grade polymorphic adenocarcinoma of papillary type. Morphological and immunohistochemical study]. 171 19

The clinical, light microscopic, and immunohistochemical features of 14 sinonasal malignant melanomas were studied to show their diverse morphologic appearance and distinction from therapeutically more amenable neoplasms that occur in this region. The tumors arose in 6 men and 8 women (median age, 70 years). Eleven patients died of disease 7 to 44 months (median, 18 months) after diagnosis. The absolute median survival time was 18.5 months (range, 7 to 44 months). The predominant microscopic appearance was categorized as small blue cell in eight cases, spindle cell in three cases, epithelioid in two cases, and pleomorphic in one case. Eight tumors had multiple patterns. Five sinonasal malignant melanomas had theque-like growth, five had junctional change, and 10 contained at least rare melanin pigment. Fourteen, 13, and 12 sinonasal malignant melanomas were immunoreactive with anti-vimentin, HMB45, and anti-S100 protein antibodies, respectively. One epithelioid tumor positive for vimentin, S100, and HMB45 also contained scattered epithelial membrane antigen-positive and cytokeratin-positive cells, which emphasizes the need for a battery of stains to distinguish sinonasal malignant melanoma from carcinoma. All tumors were negative for leukocyte common antigen, muscle-specific actin, and synaptophysin. Diffuse immunopositivity for vimentin, S100 protein, and HMB45 allows distinction of sinonasal malignant melanomas from histologically similar neoplasms.
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PMID:Sinonasal malignant melanoma. A clinicopathologic and immunohistochemical study of 14 cases. 172 Sep 20


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