Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0027627 (metastases)
 103,950 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

T1-weighted gradient-echo magnetic resonance images can be acquired with an echo time such that water and lipid spins are in phase or opposed phase. Observation of relative loss of signal intensity on opposed-phase images compared with that on in-phase images allows qualitative assessment of relatively small amounts of lipid in tissues. Conversely, frequency-selective fat saturation techniques are useful primarily for identifying predominantly fatty masses such as angiomyolipomas. Both in-phase and opposed-phase images should be acquired with similar parameters because unequivocal identification of lipid requires comparison with in-phase images to control for T1 and T2* effects. Opposed-phase imaging has been used to differentiate adrenal adenomas, which contain lipid, from adrenal metastases, which do not. The technique can be expanded to examine a spectrum of intraabdominal tumors and conditions that are characterized by intracellular lipid. These include hepatic steatosis, hepatocellular neoplasms, myelolipoma, adrenocortical carcinoma, angiomyolipoma, and renal cell carcinoma. In liver masses, the presence of lipid is largely restricted to primary hepatocellular tumors. Renal and adrenal masses may contain focal fat (angiomyolipomas and myelolipomas, respectively) or diffuse lipid (clear cell renal carcinomas and adenomas, respectively).
 ...
PMID:Detection of lipid in abdominal tissues with opposed-phase gradient-echo images at 1.5 T: techniques and diagnostic importance. 982 Nov 95

A case of large sized angiomyolipoma with atypical clinical presentation is reported. The retroperitoneal mass, showed by ultrasonography, was mainly made by fat tissue, as showed by CT and MRI, and it was associated with focal, probably metastatic, liver lesions. The diagnostic hypothesis of retroperitoneal liposarcoma with liver metastases was made. In the same time a colon neoplasm was found and US-guided biopsies of both the liver lesions and the retroperitoneal mass were carried out. The former were found to be metastases from colon cancer while the latter was a renal angiomyolipoma. The reported case underlines that renal angiomyolipoma if large sized and with atypical clinical presentation may be difficult to differentiate from retroperitoneal, even malignant masses. The hystological evaluation by means of needle biopsy or surgical resection becomes therefore mandatory.
 ...
PMID:[Giant renal angiomyolipoma. Presentation of a case]. 984 22

Angiomyolipoma (AML) is a benign neoplasm that occurs either sporadically or in patients with tuberous sclerosis complex (TSC) and shows frequent allelic losses at chromosome arm 16p. It has been suggested recently that the melanogenesis marker-positive perivascular epithelioid cell (PEC) has been found consistently in AML. The authors report a 50-year-old woman without evidence of TSC affected by classic renal AML containing an area composed of atypical epithelioid cells with the same morphoimmunophenotypic characters of PEC. After 7 years from surgical removal of the lesion, the patient developed a local recurrence and successive lung and abdominal metastases that showed morphologic and immunohistochemical features overlapping those of the epithelioid area of the previously removed AML. Genetic analysis showed that the classic AML and its epithelioid area as well as the pulmonary and abdominal metastases shared the same allelic loss on chromosome arm 16p. Based on these findings, the authors view this case as evidence of a malignant transformation of a classic AML with morphologic, immunophenotypic, and genetic demonstration of its clonal origin.
 ...
PMID:Renal angiomyolipoma with epithelioid sarcomatous transformation and metastases: demonstration of the same genetic defects in the primary and metastatic lesions. 1084 94

A variety of pediatric renal masses may be differentiated from Wilms tumor on the basis of their clinical and imaging features. Wilms tumor is distinguished by vascular invasion and displacement of structures and is bilateral in approximately 10% of cases. Nephroblastomatosis occurs most often in neonates and is characterized by multiple bilateral subcapsular masses, often associated with Wilms tumors. Renal cell carcinoma is unusual in children except in association with von Hippel-Lindau syndrome and typically occurs in the 2nd decade. Mesoblastic nephroma is the primary consideration in a neonate with a solid renal mass. Multilocular cystic renal tumor is suggested by a large mass with multiple cysts and little solid tissue. Clear cell sarcoma is distinguished by frequent skeletal metastases, and rhabdoid tumor is distinguished by its association with brain neoplasms. Angiomyolipoma frequently contains fat and is associated with tuberous sclerosis. Renal medullary carcinoma occurs in patients with sickle cell trait or hemoglobin SC disease and manifests as an infiltrative mass with metastases. Ossifying renal tumor of infancy is differentiated from mesoblastic nephroma by the presence of ossified elements. Metanephric adenoma lacks specific features but is always well defined. Renal lymphoma is characterized by multiple homogeneous masses, often with associated adenopathy.
 ...
PMID:Pediatric renal masses: Wilms tumor and beyond. 1111 13

The perivascular epithelioid cell has been proposed to be the unifying proliferating cell type in a number of lesions such as angiomyolipoma, lymphangiomyomatosis, clear cell "sugar" tumor and renal capsuloma. With the exception of rare examples of angiomyolipoma, they are non-metastasizing. We report four examples of a new member of this family of perivascular epithelioid cell neoplasms that occur in abdominopelvic location and show metastatic properties. The patients, all women, were aged 19 to 41 years (mean, 32), and presented with a tumor mass involving the serosa of the ileum, uterus or pelvic cavity. Morphologically, the tumors were composed of sheets of large polygonal cells with glycogen-rich clear or eosinophilic cytoplasm and moderately pleomorphic nuclei, traversed by a delicate vasculature, mimicking clear cell carcinoma. There were areas of coagulative necrosis and occasional mitotic figures. Intracytoplasmic brown pigment was present in two cases. Spindly cells, smooth muscle and fat were absent. Lymphovascular invasion was present in all, lymph node metastasis was documented in two and metastasis to the ovary was present in one case. Two patients developed widespread metastatic disease after 10 and 28 months from diagnosis. One patient showed the clinical signs of tuberous sclerosis. In spite of the epithelial-like appearance, the tumor cells were negative for epithelial markers but were strongly positive with the melanogenesis-related marker HMB45. Another melanogenesis marker (MART-1) was positive in two cases. Other markers including S-100 protein, vimentin, muscle-specific actin, desmin and chromogranin A were negative. Thus, these tumors are not readily classifiable in the existing schema of known entities, and show overlapping morpho-phenotypic features of clear cell "sugar" tumor of the lung and epithelioid angiomyolipoma. We consider them as sarcomas composed of a pure population of uncommitted perivascular epithelioid cell, that lack modulation toward smooth muscle or adipose cells.
 ...
PMID:Abdominopelvic sarcoma of perivascular epithelioid cells. Report of four cases in young women, one with tuberous sclerosis. 1179 46

Kidney tumors represent a wide scale of histological observations. However, only angiomyolipoma can be recognised preoperatively from results of the graphical examination. Other types can be recognised only on the bases of histological examination. Completely benign tumor is oncocytoma (it represents about 5% of all kidney tumors). Angiomyolipoma (2%) is also benign, though some case reports describing its malign transformation has been published. Angiomyolipoma under 4 cm can be only monitored, the larger tumors should be resected or selectively embolised the arterial blood supply to prevent spontaneous rupture. From the group of benign tumors only cystic nephroma can be diagnosed more often (up to 1%). One of the criteria for diagnosing the renal cortical adenoma is its size under 5 mm. That is why any adenoma, which could be diagnosed by means of graphical examination and therefore clinically significant does not exist. Most of tumors are malign epithelial tumors--renal carcinomas (RC). The are classified according Heidelberg classification into 5 elementary types: clear cell, papillary, chromophobe, originating form collecting ducts and not classifiable. Clear cell (conventional) renal carcinoma (CRC) comes most often (70 to 80%), its malign potential rise with increased size of tumor and with the gradient. Five-year survival is achieved in 30-50%. Granular form of CRC carcinoma (7% of all CRC) is the equivalent of poorly differentiated PRC and it has an adverse prognosis. In contrary, the cystic form of CRC (about 6%) in benign. Papillary form of RC has the five-year survival in 84%, malignant are only tumors poorly differentiated. These are tumors with extensive necroses, which brings a fragile consistency and they can be distinguished by graphical examination. Chromophobe type of RC (5%) has the five-year survival in 90%. Poor prognosis has its sarcomatoid form, which can originate from any RC, but most frequently it is derived from the chromophobe type. The form originating from collecting ducts is highly infrequent and very malignant with the five-year survival in 20% only. The unclassified form of RC (3-5%) includes tumors not suiting to the criteria of the previous RC. Other primary renal malignant tumors (sarcomas, Wilms' tumor of adults, medullar carcinoma, carcinoid) are very rare. Comparatively frequent are metastases of other tumors (namely that of lung carcinoma) and renal impairment in leukemia, which are complication not often met by urologist.
 ...
PMID:[Histologic classification of kidney tumors for clinical practice in adults]. 1150 85

Renal angiomyolipoma is considered to be a benign renal tumor composed of atypical blood vessels, smooth muscles and fat cells. We report 2 cases of unilateral renal angiomyolipoma. In both cases, our preoperative diagnosis was renal cell carcinoma, because no low density area compatible with fat tissue was noted in the tumors on radiographic evaluation. Through histological examination, both tumors proved to be angiomyolipomas mainly composed of epithelioid cells in 1 case, and spindle-shaped smooth muscle cells mimicking a leiomyoma in the other case. Both patients are well showing no evidence of metastases 16 and 14 months after nephrectomy, respectively.
 ...
PMID:Variants of renal angiomyolipoma closely simulating renal cell carcinoma: difficulties in the histological diagnosis. 1211 46

Lymphangiomyomatosis (LAM) is characterized by the proliferation of abnormal smooth muscle cells and cystic degeneration of the lung. LAM affects almost exclusively young women. Although lung transplantation provides effective therapy for end-stage LAM, there are reports of LAM recurrence after lung transplantation. Whether these recurrent LAM cells arise from the patient or the lung transplant donor is an area of controversy. We used microsatellite marker fingerprinting and TSC2 gene mutational analysis to study a patient with recurrent LAM after single-lung transplantation. The DNA microsatellite marker pattern indicated the presence of patient-derived LAM cells in the allograft. A somatic one base pair deletion in exon 18 of the TSC2 gene was identified in pulmonary and lymph node LAM cells before transplantation. The same mutation was in the recurrent LAM, demonstrating that the recurrent LAM was derived from the patient. Fluorescence in situ hybridization revealed that cells immunoreactive with the monoclonal antibody HMB-45 did not contain a Y chromosome. These data indicate that histologically benign LAM cells can migrate or metastasize in vivo to the transplanted lung. In addition, the patient had no evidence of a renal angiomyolipoma at autopsy and therefore demonstrated for the first time that somatic TSC2 mutations cause LAM in patients without angiomyolipomas.
 ...
PMID:Recurrent lymphangiomyomatosis after transplantation: genetic analyses reveal a metastatic mechanism. 1241 Dec 87

Monotypic epithelioid angiomyolipoma (EAML) is an uncommon variant of angiomyolipoma, occurring primarily in the kidney and characterized by a predominance of HMB-45-positive epithelioid cells. EAML is generally considered a benign neoplasm, though rare cases exhibiting malignant behavior have been reported. We describe a patient with a primary retroperitoneal monotypic EAML, composed exclusively of atypical epithelioid cells, which metastasized to the liver and the mediastinum. This case represents, to our knowledge, the first description of metastatic disease occurring in an EAML of this particular site.
 ...
PMID:Malignant monotypic epithelioid angiomyolipoma of the retroperitoneum. 1289 58

Angiomyolipoma (AML) is a common renal tumor and mostly benign in entity. Malignant AML is extremely rare and most of them are found to be epithelioid AML histopathologically. We report the imaging features of a malignant epithelioid AML in a 58-year-old patient with liver and nodal metastases, and review the literatures. We have observed that AML of epithelioid subtype with tumoral necrosis may suggest the malignant change.
 ...
PMID:Malignant renal epithelioid angiomyolipoma with aggressive behavior and distant metastasis. 1290 74


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