Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We report an unusual large, multicystic, posterior fossa neuroepithelial neoplasm involving the cerebellum, brain-stem, and quadrigeminal cistern of a 9-month-old girl. The neoplasm consisted of variably sized, sharply demarcated nests of small cells with a high nuclear-cytoplasmic ratio and moderately basophilic nuclei, embedded in a desmoplastic, immature-appearing, mesenchymal stroma. The nests contained mitoses but none were seen in the stroma. Glial fibrillary acidic protein (GFAP), neurofilament protein, synaptophysin, and cytokeratin (AE-1) were expressed in the nests. Mesenchymal cells were negative for neural markers but positive for vimentin and desmin. The neoplasm was interpreted as a mixed mesenchymal and primitive neuroectodermal tumor (PNET) with histologic features reminiscent of a recently described intraabdominal desmoplastic small cell tumor. The tumor responded poorly to chemotherapy and a second operation was performed 1 year later. The second specimen bore no resemblance to the original and consisted of epithelial-like nests and clusters of neoplastic cells frequently interrupted by sinusoidal vessels. Tumor cells had medium-sized vesicular nuclei with small nucleoli, and a granular cytoplasm. Occasional less cellular islands of neuropil-like tissue contained larger cells having eccentric, vesicular nuclei with prominent nucleoli and abundant pink cytoplasm. Mitoses were not conspicuous. Many cells expressed synaptophysin, neurofilament protein, and GFAP. Neurofilament protein was strongly positive in the larger, neuron-like cells and synaptophysin stained the neuropil-like areas strongly but was less prominent in the neuronal perikarya. Unexpectedly, the neuropil-like areas expressed epithelial membrane antigen, whereas the neuronal cells were negative for chromogranin A. The peculiar histologic picture, combination of phenotypic markers, and remarkable biologic behavior of this unusual tumor defies classification according to existing nomenclature and exemplifies the broad range of phenotypes expressed by primitive neuro-epithelial neoplasms.
 ...
PMID:Desmoplastic primitive neuroectodermal tumor with divergent differentiation. Broadening the spectrum of desmoplastic infantile neuroepithelial tumors. 138 73

We analyzed 46 gastrointestinal stromal tumors (GISTs) using a panel of antibodies to determine the frequency of smooth muscle differentiation and the relationship of immunophenotype to histopathologic features and clinical behavior. Thirty-six GISTs were classified as benign or malignant based exclusively on clinical behavior; a 2-year minimum follow-up was required for benign lesions. GISTs were immunopositive in the following categories: vimentin 45 of 46, desmin nine of 45, muscle-specific actin (MSA) 36 of 46, alpha-smooth muscle actin (SMA) 34 of 46, chicken gizzard actin-7 zero of 38, cytokeratin two of 46, S100 protein six of 46, glial fibrillary acidic protein (GFAP) zero of 46, synaptophysin zero of 46, and chromogranin one of 46. At least one muscle marker was positive in 39 of 46 tumors. Five GISTs were MSA positive/SMA negative, and three were MSA negative/SMA positive. All desmin-positive cases reacted with MSA or SMA. Eight GISTs were positive for vimentin, MSA, SMA, and desmin, whereas seven were vimentin positive only. Compared with the latter, the former tended to be smaller, less often necrotic, and clinically benign (p less than 0.05 for each). All vimentin-positive only GISTs were malignant. Immunohistochemical features did not correlate with tumor site, cellularity, nuclear pleomorphism, or mitotic rate. Benign GISTs were less cellular than were malignant GISTs (p less than 0.05), but they did not differ statistically in degree of nuclear pleomorphism, necrosis, mitotic rate, or size. We conclude that (a) 85% of GISTs react with at least one muscle antibody; (b) immunohistochemical features are unrelated to anatomic site; (c) SMA is, in effect, as sensitive as MSA, whereas desmin is less sensitive; and (d) simultaneous vimentin, MSA, SMA, and desmin positivity correlates with a benign outcome.
 ...
PMID:Muscle differentiation and clinicopathologic features of gastrointestinal stromal tumors. 141 3

Progressive unilateral sensorineural deafness and tinnitus developed in a 59-year-old woman over a 1-year period. Clinical examination showed a tumor mass which almost completely filled the tympanic cavity, and grew around the auditory ossicular chain. Histological findings revealed the tumor to be a primary carcinoid of the middle ear. Neuro-endocrine differentiation was confirmed immunohistochemically by positivity for neuron-specific enolase, chromogranin, pancreatic polypeptide and synaptophysin. Using electron microscopy, neuroendocrine granules could be visualized. In addition, both light and electron microscopy revealed that cells had an epithelial differentiation with mucin granules while immunohistochemistry showed a positivity for cytokeratins. The detection of intermediary filaments (immunohistochemically with vimentin and under electron microscopy) was unique to this neoplasm and has to be considered in distinguishing the carcinoid tumor from the papillary adenoma of the middle ear. Tumor prognosis is excellent with radical extirpation from the middle ear. In the case presented, there has been no evidence for either recurrence or metastases 10 months after surgical resection.
 ...
PMID:[Carcinoid of the middle ear: a rare tumor with biphasic differentiation. Case report with special reference to immunohistochemistry and electron microscopy]. 142 31

Synaptophysin expression was studied in seven "ependymomas" induced by transplacental administration of ethyl-nitrosourea in rats. In all the cases, strong positivity for synaptophysin was found on tumor cells. This finding supports previous studies suggesting that ENU-induced brain tumors considered to be ependymal neoplasms, are, in fact, primitive neuroectodermal tumors.
 ...
PMID:Synaptophysin expression in "ependymal tumors" induced by ethyl-nitrosourea in rats. 144 43

Central neurocytomas are rare intraventricular tumors. Patients with such tumors have a favorable prognosis after surgical removal. These tumors may be misdiagnosed as neuroblastomas or gliomas, risking the complications of adjuvant therapy. Diagnosis of central neurocytoma requires that the tumor shows the ultrastructural features of mature neuronal differentiation, including the presence of synapses and dense-core and clear vesicles in addition to profiles of neuritic processes with microtubules. The cytoskeletal phenotype of central neurocytomas has not been previously characterized, but it may facilitate their definitive recognition when ultrastructural examination is not possible. Ten central neurocytomas were examined by immunohistochemistry for phosphorylation-dependent/independent neurofilament epitopes, neuron-associated class III beta-tubulin, microtubule-associated proteins (MAP2, tau), and glial fibrillary acidic protein (GFAP). The neuronal nature of all neoplasms was documented by immunoreactivity for synaptophysin in nine tumors and for phosphorylation-independent neurofilament-H/M in the remaining case. Electron microscopy in four cases showed synapses and dense core vesicles. All tumors were immunoreactive for class III beta-tubulin and MAP2, which were seen in cytoskeletal structures by immunoelectron microscopy. Two thirds of the cases were immunohistochemically positive for neurofilament epitopes. None of the tumor cells displayed GFAP immunoreactivity, although reactive astrocytes were present. These data suggest that central neurocytomas may be recognized by synaptophysin immunoreactivity and that the expression of cytoskeletal epitopes indicates that these tumors are well-differentiated neuronal neoplasms.
 ...
PMID:Cytoskeletal immunohistochemistry of central neurocytomas. 147 23

The immunoreactivity of a panel of poly- and monoclonal antibodies raised against different neuronal and glial antigens, was studied in paraffin-embedded specimens of five pineocytomas. Antibodies against neuron-specific enolase (NSE), S-100 protein, neurofilaments protein (NFP), glial fibrillar acidic protein (GFAP), myelin basic protein (MBP), Synaptophysin (SYN) and vimentin were used. NSE immunoreactivity was detectable in nearly all tumoral cells. S-100 expression was present in all tumors, but a significant variation in the number of S-100 positive cells was noted in the different specimens; they ranged from 3% of S-100 positive cells in some areas of case 1, to 30% in other areas of case 4. The number of GFAP-positive cells detected in four of the five tumors was minimal. In the remaining tumor, 10% to 14% the positively GFAP antisera-stained cells could be seen in some areas; this tumor was considered a pineocytoma with astrocytic differentiation. MBP immunoreactivity was found in isolated cells only in one tumor. Neurofilaments or vimentin expression could not be found in tumoral cells. Synaptophysin was studied in two tumors (cases 4 and 5). Both tumors showed a fine granular neuropil pattern of immunoreactivity, but only in isolated cells of case 5, occasional cytoplasmic positivity could be determined. Based upon our results we can conclude that NSE and synaptophysin are markers that may be applied in the diagnosis of pineocytomas. Further, our results support the hypothesis that the tumoral cells in these neoplasms are of neuroendocrine origin.
 ...
PMID:Immunohistochemical characterization of pineocytomas. 147 13

To verify the practical utility of immunohistochemical analysis of bone marrow biopsy specimens in patients with neuroblastoma, we compared the results of routine histologic examination of 68 specimens with the results of immunohistochemical detection of tumor cells using an antibody to neuron-specific enolase (NSE). A commercially available polyclonal antibody to this enolase isoform consistently reacted with the neoplastic cells in biopsy specimens with histologic features diagnostic of (24 specimens) or suspicious for (one specimen) metastatic neuroblastoma. Immunohistochemical double-staining techniques documented that the NSE-positive neoplastic cells also reacted with antibodies to chromogranin and synaptophysin. Notably, anti-NSE detected small foci of metastatic neuroblastoma in two of 43 biopsy specimens that showed no evidence of metastatic tumor in the initial histologic sections. Rare NSE-reactive hematopoietic cells were present in approximately a third of the specimens with and those without neuroblastoma and were easily distinguished from metastatic tumor by morphologic examination. We conclude that this antibody to NSE consistently detects neuroblastoma cells in routinely processed bone marrow specimens, including small foci of tumor cells not evident in initial histologic sections.
 ...
PMID:Detection of metastatic neuroblastoma in bone marrow biopsy specimens with an antibody to neuron-specific enolase. 149 35

Six infants with acute megakaryoblastic leukemia and a translocation (1;22)(p13;q13) were studied. There were five female infants and one male infant, and the age at initial examination varied from 0.8 to 6.5 months (median, 2.3 months). All the patients had hepatosplenomegaly and anemia (6 to 8.3 g/dL), and four patients had thrombocytopenia (9,000 to 63,000/mm3). The bone marrow showed prominent fibrosis in five cases and reticulin fibrosis in one patient at presentation. Crush artifact often made the histologic sections difficult to interpret, but typical megakaryoblasts could be identified in the smears. Biopsy specimens of the liver and lymph node were suggestive of a nonhematopoietic malignant condition because of the cohesiveness of the tumor cells, stromal fibrosis, and the prominent sinusoidal and vascular pattern of infiltration. Immunophenotyping of peripheral blood mononuclear cells was helpful in identifying the blasts as belonging to the megakaryoblastic lineage. Using a panel of mononclonal antibodies, it was also possible to confirm the nature of the infiltration in paraffin sections and to differentiate it from other childhood small round cell tumors, especially neuroblastoma in paraffin sections (typical staining pattern: CD45-, CD43+, vW Factor, Ulex europeus I+, CD20-, CD45RO-, synaptophysin-, chromogranin-, cytokeratin-, desmin-). This special type of infantile acute leukemia can be recognized with confidence if one is aware of its clinical features, peculiar pathologic characteristics, the morphologic features and immunophenotype of the megakaryoblasts, and the unique cytogenetic abnormality.
 ...
PMID:Acute megakaryoblastic leukemia in infants with t(1;22)(p13;q13) abnormality. 151 33

We present four cases of infantile cerebellar neoplasms composed of cells with large vesicular nuclei with prominent nucleoli. All four cases were strongly immunoreactive for synaptophysin, and one case showed immunoreactivity for neurofilaments. Filter hybridization for N-myc and c-myc oncogenes showed a 27-fold c-myc amplification in one case. The cytogenetic analysis in this case showed Double-Minutes and isochromosome 17q. An intracerebral xenograft in nude mice obtained from one such tumor showed a similar morphology to that of the original tumor as well as strong immunoreactivity for synaptophysin and neurofilaments. All the neoplasms were characterized by highly aggressive behavior leading to early cerebrospinal fluid dissemination despite radiotherapy and chemotherapy. We conclude that large-cell medulloblastoma represents a distinct and more aggressive variant of medulloblastoma that requires more aggressive therapy.
 ...
PMID:Large-cell medulloblastomas. A distinct variant with highly aggressive behavior. 153 Jan 8

In a 64-year-old woman, a solitary pulmonary nodule developed 30 months after combination chemotherapy and thoracic irradiation had been administered for small-cell carcinoma of the ipsilateral lung. No evidence of extrapulmonary tumor was identified, and the nodule was excised. The well-circumscribed tumor had histologic features of a malignant ependymoma. Immunohistochemical staining showed strong reactivity for glial fibrillary acidic protein; staining for S-100 protein, Leu-7, and vimentin was less intense. Focal reactivity for epithelial membrane antigen was also present. Stains for keratin, synaptophysin, and chromogranin were negative. Electron microscopy showed cohesive cells, the cytoplasm of which contained intermediate filaments. Rare well-formed junctions were also noted. Flow cytometry of formalin-fixed paraffin-embedded tissue demonstrated DNA aneuploidy. Six months after the ependymoma was diagnosed, the patient, who had a history of hypertension, died of an intracerebral hemorrhage.
 ...
PMID:Primary malignant ependymoma of the lung. 154 54


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>