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Query: UMLS:C0027627 (metastases)
 103,950 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The perivascular epithelioid clear cell tumor (PEComa) has been described in a number of locations, including the pancreas, uterus, bladder, prostate, and gastrointestinal tract. We report the existence of a similar tumor occurring in the distal common bile duct of a 51-year-old man admitted for obstructive jaundice. The tumor had characteristic histologic features of a PEComa, including a richly vascular organoid architecture, tumor cells with clear to lightly eosinophilic cytoplasm, and variably prominent nucleoli. Immunohistochemically, the tumor cells were positive for HMB-45 and neuron specific enolase but negative for epithelial markers, smooth muscle markers, other neuroendocrine markers, vimentin, melan-A, and S-100 protein. PEComas appear to be ubiquitous tumors with characteristic histology and immunophenotype. Although most of these tumors have behaved in a benign fashion, they should be considered tumors of uncertain malignant potential given previous reports of recurrence and metastases. During a short follow-up period following a conservative local excision, our patient remains free of disease.
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PMID:Perivascular epithelioid clear cell tumor of the common bile duct. 1525 21

Tumours of perivascular epithelioid cells (PEComas) are being increasingly reported at visceral and somatic sites. Both benign and malignant variants have been identified, although clinical follow-up is often limited, which prevents meaningful predictions of behavior. We report the case of a malignant soft tissue PEComa with histologically confirmed regional lymph node metastases and radiologically confirmed pulmonary metastases. The light microscopic appearance and immunohistochemical profile (HMB-45, smooth muscle actin positive) and electron microscopic appearance support perivascular epithelioid cell differentiation.
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PMID:Malignant perivascular epithelioid cell tumour ("PEComa") of soft tissue: a unique case. 1557 88

We report two cases of digestive/intra-abdominal PEComa. The first lesion developed in the caecum of a 36-year-old woman, the second in the pararectal region of a 35-year-old woman. The first tumor was formed from spindle cells arranged in fascicles, the second contained predominantly epithelioid cells with prominent nucleoli. Immunohistochemically, tumor cells expressed smooth muscle actin and melanocyte markers (HMB45), S-100 protein and CD117 were negative. Based on the morphologic aspect and, above all, on the immunohistochemical study the diagnosis of PEComa was retained for both lesions. In the gastrointestinal tract, the principal differential diagnoses of PEComas are gastrointestinal stromal tumors, particularly the round cell/epithelioid subtype, and metastases of carcinoma and melanoma. Other differential diagnoses include rhabdomyosarcoma, paraganglioma, leiomyosarcoma, and clear cell sarcoma.
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PMID:Digestive PEComas: a solution when the diagnosis fails to "fit". 1561 43

Perivascular epithelioid cell tumor (PEComa) is a group of rare tumors composed of epithelioid cells with characteristic perivascular distribution and co-expression of the melanogenic marker HMB-45 and muscular markers. There are no documented parameters referring to the biologic behavior of PEComa. We report an abdominopelvic PEComa with overt malignancy in a 16-year-old girl. Histologically, the tumor showed the typical morphophenotypic characteristics of PEComa. Though the cytologic appearance of the tumor cells was relatively bland, the extensive necrosis, presence of lymph node metastases, and surrounding tissue invasion were all indicative of malignancy. Relapse of the tumor with multiple lymphadenopathy shortly after debulking surgery for the primary lesion, and postoperative adjuvant chemotherapy, further denoted its aggressive behavior.
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PMID:Abdominopelvic perivascular epithelioid cell tumor with overt malignancy: a case report. 1603 71

Uterine perivascular epithelioid cell tumor (PEComa) is very rare, and there have been only 27 reported cases. The differentiation of the tumor has been enigmatic, and the biologic behavior remains unclear. This study describes the clinical, histologic, and immunohistochemical features of four cases of uterine PEComa. The patients were 30, 32, 36, and 40 years old, and none of them had tuberous sclerosis complex. The size of the tumors ranged from 1 to 30 cm in diameter, and 3 of the 4 tumors were confined in the uterus. One tumor involved the left ovary and omentum. Microscopically, the tumors were characterized by an epithelioid arrangement of tumor cells, which had abundant clear to eosinophilic pale granular cytoplasm, and one tumor had moderately atypical nuclei. Coagulative necrosis was found in two cases. The mitotic figures ranged from 0 to 11 per 10 high power fields. Immunohistochemically, the tumors were positive for vimentin (4/4), HMB45 (4/4), h-caldesmon (4/4), alpha-smooth muscle actin (3/4), muscle actin (2/4), and desmin (3/4). They were uniformly negative for Melan A, CD10, and S-100 protein. Ultrastructural examinations were performed on one case and revealed no melanosomes, premelanosomes, or evidence of smooth muscle differentiation. One patient died of intestinal metastases 17 months after surgery. The other patients have been well with no evidence of disease 8, 12, and 36 months after surgery. Uterine PEComa should be regarded as tumors with an uncertain malignant potential until long-term outcome data for a larger number of patients become available.
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PMID:Perivascular epithelioid cell tumor of the uterus: report of four cases. 1617 79

Epithelioid angiomyolipoma (AML) is the prototype of a heterogeneous group of lesions characterized by the presence of HMB-45 positive cells with clear cytoplasm, perivascular distribution, and combined myomelanocytic features, so-called perivascular epithelioid cells (PECs). These lesions are being increasingly referred to as PEComas. PEComas have been reported at diverse anatomic sites, but mainly in the abdominopelvic cavity and rarely in parenchymatous organs, skin, and soft tissues. Gastrointestinal (GI) PEComas are exceptionally rare, with less than 10 cases documented so far. Rare examples of PEComas with pleomorphic histology could have been misinterpreted as unusual variants of carcinoma or sarcoma. To make a contribution to the differential diagnosis of difficult-to-classify pleomorphic GI sarcomas, we report on a malignant pleomorphic neoplasm with features of PEComa involving the terminal ileum in a 63-year-old woman. Fourteen months after resection of the primary tumor, a huge abdominopelvic recurrence was successfully resected, but no distant metastases were detected. The differential diagnosis and malignancy criteria of GI PEComas will be discussed.
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PMID:Perivascular epithelioid cell sarcoma (malignant PEComa) of the ileum. 1634

Neoplasms of perivascular epithelioid cells (PEComas) have in common the coexpression of muscle and melanocytic immunohistochemical markers. Although this group includes entities with distinct clinical features, such as angiomyolipoma, clear cell sugar tumor of the lung, and lymphangioleiomyomatosis, similar tumors have been documented in an increasing diversity of locations. The term PEComa is now generally used in reference to these lesions that are not angiomyolipomas, clear cell sugar tumors, or lymphangioleiomyomatoses. While most reported PEComas have behaved in a benign fashion, malignant PEComas have occasionally been documented. We present a case of hepatic PEComa with benign histologic features, which nonetheless presented with metastases to multiple sites nearly 9 years later. This case represents the second documented malignant PEComa of the liver, as well as the longest follow-up of a surviving patient with a malignant PEComa, emphasizing both the need for criteria that more accurately predict the behavior of PEComas and the necessity of long-term follow-up of patients with PEComas.
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PMID:Malignant neoplasm of perivascular epithelioid cells of the liver. 1687 28

Perivascular epithelioid cell tumor (PEComa) is rare entity and has been described only recently. By immunohistochemistry and genetics it belongs to the family of tumours which comprises angiomyolipoma, clear cell "sugar" tumor of lung, lymphangioleiomyomatosis and clear cell myomelanotic tumor of ligamentum falciforme/teres hepatis. We describe an unusual case of hepatic PEComa arising in a 55-year-old woman with previous history of glioblastoma. Histologically the tumor grew in expansive way, and was composed of clear and eosinophilic epithelioid cels, without vascular or lipomatous component characteristic of angiomyolipoma. There was mild nuclear pleomorphism, sporadic mitotic activity and haemorrhage without necrosis. On immunohistochemistry, the tumor was HMB-45+50, Melan-A and smooth muscle actin positive. Tyrosinase, S-100 protein, cytokeratin coctail, EMA, vimentin, muscle specific actin, CD10, TTF-1, hepatocyte, desmin and cyclin D1 were negative. Sporadic nuclear p53 positivity was seen. The main differential diagnosis of hepatic PEComa includes clear cell variant of liver cell adenoma and hepatocellular carcinoma, metastases of various clear cell carcinomas and metastasis of malignant melanoma. In respect of uncertain biologic potential of PEComa, long term follow up is indicated.
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PMID:[Perivascular epithelioid cell tumor (PEComa) of the liver: a case report and review of the literature]. 1737 Apr 72

PEComas (tumors showing perivascular epithelioid cell differentiation) are a family of mesenchymal neoplasms that include angiomyolipoma, clear cell "sugar" tumor of the lung, lymphangiomyomatosis, and a group of uncommon lesions that arise in soft tissue, visceral organs, and skin. We describe a distinctive variant of PEComa that shows extensive stromal hyalinization, a feature not previously described in these tumors. Thirteen PEComas with extensive stromal hyalinization were identified from a total of 70 cases of PEComa received between 1996 and 2006 (19%). All patients were women, with a mean age of 49 years (range, 34 to 73y). One patient had tuberous sclerosis. Ten tumors (77%) arose in the retroperitoneum (8 pararenal), and 1 each in the pelvis, uterus, and abdominal wall. Median tumor size was 9.5 cm (range, 4.5 to 28 cm). All except 2 were grossly well-circumscribed. The tumors were composed of cords and trabeculae of cytologically uniform bland epithelioid cells with palely eosinophilic, granular to clear cytoplasm and round nuclei with small nucleoli, embedded in abundant densely sclerotic stroma. Five tumors contained a spindle cell component, and 6 showed focally sheetlike areas. In all cases the tumor cells were focally arranged around blood vessels. All tumors lacked the delicate nesting vascular pattern typical of other PEComas. Mitoses ranged from 0 to 3/50 high-power field (mean 1) in all cases except 1. One tumor showed abrupt transition to areas with strikingly pleomorphic morphology, marked nuclear atypia, frequent mitoses (22/10 high-power field), and fascicular and nested architecture. This was the only case with necrosis. All tumors were immunopositive for desmin (usually diffusely) and HMB-45 (generally in scattered cells); 12/13 (92%) expressed smooth muscle actin, 11/12 (92%) caldesmon, 11/12 (92%) microphthalmia transcription factor (D5), and 3/13 (23%) melan-A. Only 1 (8%) was focally S-100 positive. All tumors were negative for epithelial membrane antigen, PAN-K, and KIT (CD117). Follow-up was available for 9 patients, ranging from 10 to 64 months (median, 33). One patient (whose tumor showed transition to high-grade malignant morphology) developed metastases to lung, liver, and abdominal wall. No other tumor has recurred or metastasized thus far. Sclerosing PEComa is a distinctive variant with a predilection for the pararenal retroperitoneum of middle-aged women. Sclerosing PEComas seem to pursue an indolent clinical course, unless associated with a frankly malignant component. Long-term follow-up will be required to confirm these findings.
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PMID:Sclerosing PEComa: clinicopathologic analysis of a distinctive variant with a predilection for the retroperitoneum. 1822 80

Purpose. Tumors of the perivascular epithelial cell tumor (PEComa), first described in 1992, represent a rare soft tissue neoplasm of varying malignant potential. Cases of PEComa have been previously described in a few somatic and visceral sites, most notably in the gastrointestinal tract, genitourinary tract, and one extremity case in the thigh. To date, most malignant cases of PEComa have been resistant to chemotherapy, and as such, an appropriate therapy is not known. Case report. Here we describe the first case of PEComa of the upper extremity. Open biopsy revealed a high-grade malignant lesion, and the patient subsequently underwent both neoadjuvant therapy with doxorubicin, ifosfamide and mensa, and radiation therapy prior to wide surgical resection. After six cycles of chemotherapy, the tumor underwent an 80% reduction in size. Subsequent neoadjuvant radiation therapy of 5000 cGy did not further reduce the size of the tumor. Following limb sparing radical resection, pathology showed 20% necrosis within a high-grade malignant lesion. Twenty one months after beginning treatment, the patient shows no sign of local recurrence, but metastatic disease was confirmed after resection of a lung nodule. Conclusion. Given the favorable albeit partial response seen in this patient, the course of therapy outlined here may represent a good starting point for neoadjuvant treatment in a tumor with a historically bleak prognosis. In addition, the diagnosis of PEComa must now be entertained in the differential diagnosis of upper extremity soft tissue sarcoma.
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PMID:PEComa of the Upper Extremity: A Unique Case and Description of an Initial Response to Neoadjuvant Chemotherapy. 1827 9


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