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Diffuse Proliferation (diffuse + proliferation)

Distribution by Scientific Domains

Medical Sciences	100%

Selected Abstracts

Extrarenal rhabdoid tumors of soft tissue: Clinicopathological and molecular genetic review and distinction from other soft-tissue sarcomas with rhabdoid features

PATHOLOGY INTERNATIONAL, Issue 6 2006
Yoshinao Oda
Malignant rhabdoid tumor (MRT) of the soft tissue is a rare and highly aggressive tumor that occurs in infancy or childhood. It predominantly involves a deep axial location such as the neck or paraspinal region. Microscopically, the tumor is composed of a diffuse proliferation of rounded or polygonal cells with eccentric nuclei, prominent nucleoli and glassy eosinophilic cytoplasm containing hyaline-like inclusion bodies, arranged in sheets and nests. These characteristic ,rhabdoid cells' are also present in certain soft-tissue sarcomas such as synovial sarcoma, extraskeletal myxoid chondrosarcoma and leiomyosarcoma. The existence of rhabdoid cells in these other sarcomas is correlated with a worse prognosis for the patients. Cytogenetic and molecular analyses have shown abnormalities in the long arm of chromosome 22 and alteration of the hSNF5/INI1 (SMARCB1) gene in renal, extrarenal and intracranial MRT. This gene alteration has been considered to be a specific molecular event in MRT, but a recent study has also demonstrated frequent alteration of this gene in proximal-type epithelioid sarcoma (ES). Both MRT of soft tissue and proximal-type ES show immunoreactivity for vimentin, cytokeratin and epithelial membrane antigen. The tumor cells of proximal-type ES are also occasionally positive for CD34 and ,-catenin, whereas MRT of soft tissue has no immunoreaction for these markers. Detailed clinicopathological and immunohistochemical evaluations are necessary to distinguish MRT of soft tissue from proximal-type ES, because these tumors demonstrated a similar morphology and the same gene alteration. [source]

Blastic natural killer cell lymphoma arising from the mediastinum with terminal deoxynucleotidyl transferase expression

PATHOLOGY INTERNATIONAL, Issue 1 2001
Kouichi Isobe
Blastic natural killer (NK) cell lymphoma/leukemia is a relatively rare NK cell malignancy. We report the second case of blastic NK cell lymphoma arising from the mediastinum with an aggressive clinical course. The patient was a 63-year-old Japanese man with an anterior mediastinum tumor. The biopsy specimen showed diffuse proliferation of tumor cells with frequent mitotic figures and apoptotic bodies. Both angiocentric features and small foci of coagulative necrosis were found in this section. The tumor cells had medium to large nuclei with a fine chromatin pattern, inconspicuous nucleoli and scanty cytoplasm. The nuclear contour was oval to moderately irregular, showing slight pleomorphism as compared with typical lymphoblastic lymphoma. The tumor cells were positive for CD2, CD56 and terminal deoxynucleotidyl transferase, but negative for other T-cell antigens, B-cell antigens and myeloid markers. In situ hybridization for Epstein,Barr virus encoded small ribonucleic acid 1 was negative. [source]

Recent progress in studies of infantile hemangioma

THE JOURNAL OF DERMATOLOGY, Issue 4 2010
Masatoshi JINNIN
Abstract A hallmark of infantile hemangioma, the most common tumor of infancy, is its dramatic growth after birth, by diffuse proliferation of immature endothelial cells, followed by spontaneous regression. The growth and involution of infantile hemangioma is quite different from other vascular anomalies, which do not regress and can occur at any time during life. Some hemangioma lesions can be extremely disfiguring and destructive to normal tissue and may even be life-threatening. Unfortunately, existing therapeutic approaches have limited success and significant adverse effects of some treatment modalities limit their use. Better understanding of the pathogenesis of hemangioma will enable the development of better therapeutic strategies. Here, we review recent studies and new hypotheses on the pathogenesis of the tumor. Detailed mechanisms of activated vascular endothelial growth factor signaling in tumor cells, identification of their origin and characterization of multipotent stem cells that can give rise to infantile hemangioma are shedding new light on this intriguing vascular tumor. [source]

Pathological features of diseases associated with human T-cell leukemia virus type I

CANCER SCIENCE, Issue 6 2007
Koichi Ohshima
In the early 1980s, the first human retrovirus, human T-cell leukemia virus type I (HTLV-I), was isolated and its characterization opened up the new field of human viral oncology. Adult T-cell leukemia/lymphoma (ATLL), which is associated with HTLV-I, is characterized clinically by the appearance of characteristic flower cells, a rapid clinical course, occasional skin lesions, lymphadenopathy and hepatosplenomegaly. Severe opportunistic infections are occasionally accompanied. In addition, HTLV-I infection is associated with autoimmune and reactive disorders, such as HTLV-I-associated myelopathy and uveitis, and is also related to immunodeficient infectious diseases. Pathological findings of ATLL in the lymph nodes, skin, liver and other organs have been described. Common histological features are a diffuse proliferation of atypical lymphoid cells that vary in size and shape. In addition to ATLL, non-neoplastic organopathies have been documented in many organs, such as the central nerve system, lung, skin, lymph nodes and gastrointestinal tract. To clarify the HTLV-I-associated diseases, it is important to understand the pathological variations. (Cancer Sci 2007; 98: 772,778) [source]