Search results for "Epithelioid cell"

Malignant PEComa With Metastatic Disease at Diagnosis and Resistance to Several Chemotherapy Regimens and Targeted Therapy (m-TOR Inhibitor).

2017

Perivascular epithelioid cell tumors (PEComas) are infrequent neoplasms with peculiar myomelanocytic differentiation. The aggressive abdominopelvic variant is rare, with only a small number of published cases. We present an additional case of this unusual variant, which showed an aggressive histologic and clinical behavior with multiple liver metastases and resistance to several therapies. We also discuss the histological and immunohistochemical profiles as well as the differential diagnosis.

Poorly differentiated synovial sarcoma: A case report

2001

Poorly differentiated synovial sarcoma is a rare soft tissue tumor. We studied a case arising in the pleural cavity of a young subject, characterised by the presence of spindle cell, small cell, and large epithelioid cell areas. We performed stains for mucosubstances and analysed the expression of cytokeratins 5/6, 7, 8, 18, 19, CEA, CD34, Ber-Ep4 and calretinin to characterize the phenotype of this neoplasm. We furthermore assessed immunohistochemically the presence of p53, Bcl-2, Bax and caspase 3, four apoptotic markers, to evaluate a relationship between apoptotic activity and the behaviour of this tumor. Our findings showed a strong presence of calretinin, p53 and Bcl-2 in all three ar…

Bone marrow granulomas in hairy cell leukaemia following 2-chlorodeoxyadenosine therapy

1994

Atypical Pleomorphic Extraosseous Ewing Tumor/Peripheral Primitive Neuroectodermal Tumor with Unusual Phenotypic/Genotypic Profile

2002

A pleomorphic undifferentiated tumor primarily located in the retroperitoneum with a phenotype compatible with an extraosseous Ewing tumor/peripheral primitive neuroectodermal tumor (ET/pPNET) pattern and unusual molecular features is described. Immunohistochemically, HBA-71 (CD99/mic2) and several neural markers were intensively expressed together with scattered cells expressing carcinoembryonic antigen (CEA). Short-term culture showed biphasic neuroblastic and epithelioid cell populations, with the latter expressing germ cell markers (CEA, alpha-fetoprotein, and the beta-subunit of chorionic gonadotrophin). Conventional cytogenetics displayed several chromosomic rearrangements, especially…

Primary melanoma of the oral cavity: A multi-institutional retrospective analysis in Brazil

2020

Background Melanoma is an aggressive malignant tumor, rarely observed in the oral cavity. The aim of this study was to describe the clinicopathologic features of a series of oral melanomas. Material and Methods A retrospective descriptive study was performed. A total of 15,482 biopsy records from two oral and maxillofacial pathology services in Brazil were analyzed. All cases of oral melanomas were reviewed, and clinical, demographic, histopathological data, treatment, and follow-up status were collected. In addition, immunohistochemistry stains (pan-cytokeratin AE1/AE3, vimentin, α-SMA, CD45, S-100 protein, HMB-45, Melan A, and Ki-67) were performed. Results The series comprised of 5 males…

Pleural epithelioid angiosarcoma with lymphatic differentiation arisen after radiometabolic therapy for thyroid carcinoma: immunohistochemical findin…

2017

Abstract Background Pleural angiosarcoma is a rare tumor that causes diffuse pleural thickening and effusion, mimicking mesothelioma. Immunohistochemistry is needed to highlight endothelial differentiation. We describe the first case of pleural angiosarcoma with lymphatic differentiation following radiometabolic therapy for thyroid carcinoma. Case presentation A 50-year-old man showed diffuse pleural thickening and effusion. Nine years earlier, he underwent thyroidectomy and radiometabolic therapy for thyroid carcinoma with lymph node metastases. Histologically, the tumor consisted of a solid proliferation of atypical epithelioid cells and anastomosed vascular spaces, lacking of red blood c…

Freeze-fracture features of epithelioid cells, multinucleated giant cells, and phagocytic macrophages

1987

The freeze-fracture morphology of epithelioid cells, multinucleated giant cells (Langhans' type), and phagocytic macrophages was investigated. The intensely folded and interdigitating surface membranes of epithelioid cells and multinucleated giant cells displayed no specialized areas of cell contact. The size of the intramembranous particles (IMP) and the fact that the area density of IMPs was higher in the cytoplasmic (P) faces than in the external (E) faces of the cell membranes agreed with observations in other eukaryotic cells. The area densities of the IMPs suggest lower transport rates of molecules across the cell membranes of granuloma cells than of certain epithelial cells. Small pi…

Differentiation of granuloma cells (epithelioid cells and multinucleated giant cells): a morphometric analysis

1986

Morphometric analysis disclosed distinct differences between blood monocytes, tissue monocytes (i.e. immature macrophages), epithelioid cells and multinucleated giant cells as well as phagocytic macrophages (i.e. mature macrophages) in the granuloma model of autoimmune (anti-TBM) tubulo-interstitial nephritis. The numerical density of lysosomes decreased slightly in tissue monocytes compared with blood monocytes but showed a pronounced increase during the formation of epithelioid cells. The lysosomal compartments of epithelioid cells and multinucleated giant cells resembled each other very closely, but the giant cells obviously produced additional lysosomes of small diameter (80-120 nm). Ph…

Primary malignant melanoma of the oral cavity: case report.

2002

An 80-year-old-female patient had a pigmented lesion on: the hard palate, the soft palate, the alveolar mucosa and the vestibolar mucosa of the maxillary gingiva. Pigmented macules and patchs had been persistent and asymptomatic for many years (Fig. 1). The lesion exhibited irregularities of pigmentation, border and surface contour. About 1 year later the patient had noticed an extension of the pigmented macules and plaques; there was also the appearance of nodules of the maxillary gingiva accompanied by swelling. Loosening of teeth as a result of extensive destruction of bone was further noted (Fig. 2). Figure 1. Pigmented macules and patchs with irregularities of pigmentation, border and …

Primary intra-osseous Hybrid Schwannoma-Perineurioma in the mandible

2020

Benign nerve sheath tumours include perineuriomas, schwannomas and neurofibromas. Hybrid schwannoma-perineurioma represents a cutaneous, subcutaneous or occasionally intra-osseous tumour with schwannian cytomorphology and perineurioma-like architecture consisting of a mixture of both types of cells. These tumours can develop at any age and there is no gender-predilection. Tongue is the most frequently affected site, followed by palate, mouth floor, jugal mucosa, lips and, more rarely, mandible. We present a case of hybrid tumour with schwannoma-perineurioma morphology located on the right mandibular body (intra-osseous) of a 54-year-old female patient. The tumour was symptomatic and evolvin…