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Query: UMLS:C0677930 (primary tumor)
 20,210 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Alveolar soft part sarcoma (ASPS) was described as a distinct entity in 1952. ASPS mainly affects young adults, with a slight prevalence of female patients. It arises in the extremities, trunk, and head and neck region. Metastases are frequent and are mainly localized to lungs, brain, and bone. Local recurrences are rare if the primary tumor is completely excised. Adjuvant chemotherapy or radiotherapy are not useful. Death eventually supervenes, after several years, in most of the patients. Histogenesis and differentiation of ASPS, since its first description, have remained a matter of controversy. Many hypotheses have been taken into consideration, among which neural and muscular differentiation are the most plausible. The finding that intracytoplasmic crystals, present in most of the cases, are composed of actin, and the immunocytochemical localization in ASPS of several muscular markers, such as actin (skeletal and smooth muscle actin), desmin, and MyoD1 are all features that point towards skeletal muscle differentiation.
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PMID:Alveolar soft-part sarcoma: a new type of rhabdomyosarcoma? 820 47

Cytokeratin-positive interstitial reticulum cells (CIRCs) have been described as a subset of fibroblastic reticulum cells (FBRCs) normally found in lymph nodes, the spleen, and tonsils. Although tumors derived form other reticulum (dendritic) cells, specifically follicular dendritic cells, interdigitating dendritic cells, and cytokeratin-negative FBRCs, have been well documented and are now accepted, this is not the case for tumors of CIRCs. A possible reason for this failure is the difficulty in distinguishing them from other tumors, particularly carcinoma. We report three cases of cytokeratin-positive malignant tumors with a reticulum cell morphology: two located in the mediastinum and one in the soft tissue in the proximal forearm. All cases coexpressed vimentin, and one case coexpressed smooth muscle actin and desmin, resulting in a phenotype similar to that of some normal CIRCs. Although metastatic carcinoma from an occult or regressed primary tumor cannot be excluded completely, we raise the possibility of a CIRC origin for these cases.
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PMID:Cytokeratin-positive malignant tumors with reticulum cell morphology: a subtype of fibroblastic reticulum cell neoplasm? 1063 94

We report a case of gliosarcoma with areas of primitive neuroepithelial differentiation arising in the temporal lobe of a 53-year-old man. The sarcomatous component of this tumor was perivascular in its distribution and showed expression of factor VIII-related antigen, smooth muscle actin and CD34. The primitive neuroepithelial component possessed a small cell morphology and showed expression of neuronal antigens. Strong expression of p53 was demonstrated throughout the tumor with only focal weak expression of epidermal growth factor receptor. The tumor developed widespread extraneural metastases 5 months after surgical resection of the primary tumor. Histological examination of the liver metastases showed them to consist predominantly of the primitive neuroepithelial component. We believe this to be a novel pattern of differentiation in a gliosarcoma which in this case was associated with an aggressive metastatic potential.
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PMID:Gliosarcoma with areas of primitive neuroepithelial differentiation and extracranial metastasis. 1214 29

Primary malignant tumors of the small intestine are rare. Malignant gastrointestinal stromal tumors are the third most common neoplasm among primary malignant small bowel tumors. A 56-year-old woman was admitted to our hospital because of appetite loss and dyspnea with movement. On admission, physical examination revealed severe anemia in her conjunctiva and a tumor in her left abdomen. Her hemoglobin level was 6.2 g/dL and other laboratory data were normal. Abdominal ultrasonograms and computed tomograms revealed a 55 x 70-mm heterogeneous mass and multiple low-density masses in the liver. Superior mesenteric arteriograms revealed a hypervascular tumor fed by the jejunal arteries. A malignant gastrointestinal stromal tumor arising from the jejunum with liver metastases was suspected. Partial resection of the affected jejunum and left trisegmentectomy of the liver were performed. The resected primary tumor was 120 x 45 x 65 mm. The tumor was mainly submucosal, but extended outside the jejunum; it was elastically firm and multiloculated. A small ulcer was seen on the mucosal side. The metastatic liver tumors were solid or cystic with diameters of 20 to 40 mm. Histopathological examination revealed that the tumors were characterized by fascicular proliferation of spindle-shaped cells. Immunohistochemical staining was positive for CD34 and c-kit, and negative for S-100 protein and smooth muscle actin. This case was a malignant gastrointestinal stromal tumor originating in the jejunum with liver metastases. The primary tumor and liver metastases were successfully resected simultaneously.
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PMID:Malignant gastrointestinal stromal tumor of the jejunum with liver metastasis. 1223 33

Collision tumors of the stomach are uncommon. To the best of our knowledge, this is the first case report of gastric collision tumor composed of gastrointestinal stromal tumor (GIST) intermixed with primary adenocarcinoma in the English literature. The adenocarcinoma was determined to be the primary tumor based on histologic features. The tumor cells of the GIST were diffusely and strongly positive for CD34 and CD117, weakly positive for smooth muscle actin (5% of cells), and negative for desmin, S-100 protein, synaptophysin, and cytokeratin. There was no transition between the different components. We hypothesized that the stomach was influenced by the same unknown carcinogen, resulting in a simultaneous proliferation of different cell lines (epithelial and stromal cell). This case represents an example of two independent tumors in a unique one-on-another pattern, namely growth of adenocarcinoma on GIST.
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PMID:Collision tumor of the stomach: a case report of mixed gastrointestinal stromal tumor and adenocarcinoma. 1235 97

Malignant melanoma is known to display tremendous histologic diversity. One rare variant is the rhabdoid phenotype, so called because of the appearance of cells resembling rhabdomyoblasts seen in malignant rhabdoid tumors of the kidney. We present the histologic, immunohistochemical, and ultrastructural features of a malignant melanoma composed entirely of rhabdoid cells. A 62-year-old man presented with a 6.5-cm lung mass. Although presumed to be a metastatic lesion, extensive workup failed to reveal a primary tumor site. Histologic sections showed a mass composed entirely of polygonal neoplastic cells with prominent nucleoli and large hyaline cytoplasmic inclusions. The tumor cells were strongly immunoreactive with S100 protein, vimentin, and CD56, and were focally reactive with Mart-1. Tumor cells were negative for Melan-A, tyrosinase, HMB-45, AE1/AE3, cytokeratin (CK) 7, CK8/ 18, CK20, CK903, CAM 5.2, epithelial membrane antigen, smooth muscle actin, desmin, leukocyte common antigen, Bcl-2, CD3, CD20, CD30, CD138, kappa and lambda light chains, CD68, CD34, factor VIII, synaptophysin, and glial fibrillary acidic protein. Electron microscopy showed cytoplasmic whorls of intermediate filaments containing entrapped rough endoplasmic reticulum, mitochondria, and lipid. Recognition of this rare variant of malignant melanoma is important in the evaluation of tumors with rhabdoid morphology.
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PMID:Malignant melanoma with a rhabdoid phenotype: histologic, immunohistochemical, and ultrastructural study of a case and review of the literature. 1516 28

In this report, we present two cases of axillary lymph node metastatic breast carcinoma with features mimicking ductal carcinoma in situ (DCIS): one was of the comedo-like type and the other was suggestive of the micropapillary type. In the first case, the primary tumor presented DCIS of the comedo type; however, in the second case, the primary tumor consisted only of the invasive ductal component. Immunohistochemistry against smooth muscle actin, S100-protein, CK5/6, CD10, P63, and 34betaE12 did not identify myoepithelial cells either in DICS of the first primary tumor or in both metastases. These features probably do not represent the true DCISs, but only mimic them. This observation suggests that a proportion of "primary DCIS" may constitute an invasive pseudo-DCIS carcinoma, and immunohistochemical identification of myoepithelial cells may be helpful in such cases.
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PMID:Ductal carcinoma in situ-like structures in metastatic breast carcinoma. 1579 28

The purpose of this study was to determine the clinicopathologic features of gastrointestinal stromal tumor (GIST) in southern Taiwan. The pathology files from a medical center in southern Taiwan (1993 to 2003) were searched for primary mesenchymal tumors of the gastrointestinal tract. Hematoxylin/eosin sections and history were reviewed, and immunohistochemistry was performed using anti-CD 117, CD34, smooth muscle actin (SMA), and S-100 protein. Only primary resected GISTs were included in this study. Univariate and multivariate analyses were carried out using the T-test to evaluate the significance of primary tumor size and mitotic activity for the prediction of recurrence and metastasis. A total of 121 surgically resected primary mesenchymal tumors were identified, and 93 of these were GISTs. These 93 patients showed a slight female predominance (male: female = 1:1.2). The clinical presentations were variable and site-dependent. The most common tumor locations were the stomach (57%) and the small intestine (39%). Microscopically, 88 tumors (95%) were composed of spindle cells, the remaining five (5%) consisted of mixed epithelioid and spindle cells. No pure epithelioid type GIST was found. In addition to CD117, 66 cases (71%) were positive for CD34, 23 cases (25%) were positive for SMA, and 19 cases (21%) were positive for S-100. In a mean follow-up time of 27.3 months (median: 26 months), 19 cases (20.6%) were clinically malignant and mainly manifested as liver metastases (seven cases, 37% of malignant GISTs). Univariate analysis revealed that both primary tumor size and mitotic activity were significantly increased in the group affected by recurrence and/or metastasis (p = 0.001 and 0.035, respectively). Compared to GISTs in the western countries, those in southern Taiwan are characterized by a slight female predominance, a relatively higher frequency of small intestinal localization, a higher rate of S-100 protein expression, and a less aggressive behavior. Tumor size and mitotic activity were useful predictors of malignancy.
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PMID:Gastrointestinal stromal tumor (GIST) in southern Taiwan: a clinicopathologic study of 93 resected cases. 1580 5

Five cases of gastrointestinal stromal tumor metastatic to the ovary are reported. The average patient age was 59 years (range, 44-81 years). The primary tumor was in the small bowel or its mesentery (4 cases) or stomach (1 case). The primary and metastatic tumors were discovered synchronously in 3 cases. In the other 2 cases, the ovarian tumors were discovered 18 months before a gastric tumor was identified and 27 years after a small bowel tumor had been resected. The ovarian tumors (three of which were bilateral) were usually solid, tan, and lobulated. Microscopically, three tumors had a pure spindle cell morphology, and two both spindle and epithelioid cell components. The diagnosis in all 5 cases was confirmed with positive c-kit (CD117) and negative desmin immunostaining. Variably positive immunoreactivity for either or both h-caldesmon and smooth muscle actin was seen in all 5 cases, and 3 cases were CD34-positive. Four patients died between 1 and 6.5 years (mean, 2.8 years) from the time of ovarian tumor diagnosis. The main differential diagnostic consideration was leiomyosarcoma; the most important features to help exclude this diagnosis were an absence of tumor in the uterus, low histologic grade, and a desmin-negative, c-kit-positive immunophenotype. Other differential considerations, including endometrial stromal sarcoma and fibrosarcoma, are discussed. Most of the ovarian tumors in this series were initially diagnosed as tumors of other types, a misdiagnosis with significant therapeutic and prognostic implications because of the specific therapy now available for gastrointestinal stromal tumors.
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PMID:Gastrointestinal stromal tumors metastatic to the ovary: a report of five cases. 1595 57

We report a case of gastrointestinal stromal tumor (GIST) that developed in a male F344 rat at week 101 of an experiment in a carcinogenicity study. Macroscopically, the primary tumor, which measured 1 cm in diameter, involved the submucosal tissue of the forestomach at the lesser curvature extending to the glandular stomach and esophagus. Histopathologically, the tumor was composed of neoplastic cells with small- to medium-sized spindle-shaped single nuclei and fibrillary cytoplasm lacking distinct cell borders. It invaded extensively into the tunica muscularis and subserosa, further extending to the lamina propria mucosa and serosal surface. A few densely proliferating portions showed a tendency to storiform pattern. Metastatic tumor nodules were found in the liver, spleen, and femur bone marrow, with multiple nodules, up to 1 cm in diameter, apparent in the liver. Immunohistochemically, diffuse, but weak cytoplasmic immunoreactivity for KIT was evident, and most neoplastic cells also exhibited strong immunoreactivity for a -smooth muscle actin and vimentin. Sparse nuclear S-100-immunoreactive cells were further observed, but none of neoplastic cells were immunoreactive for CD34, caldesmon, desmin, cytokeratin, or synaptophysin. Collectively, these features meet the criteria for a GIST, with limited potential for differentiation to smooth muscle and neural cells.
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PMID:A case report of a spontaneous gastrointestinal stromal tumor (GIST) occurring in a F344 rat. 1653 95


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