Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.2.1.17 (lysozyme)
21,489 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Ten tumors of true histiocytic origin (Histiocytic Sarcoma) are presented. The tumor cells were identified as histiocytes by immunological, cytochemical and ultrastructural criteria (cytoplasmic lysozyme activity, presence of C3 and Fc gamma receptor, strong acid phosphatase and alpha-naphthyl acetate esterase activity, presence of lysosomes, absence of cell junctions and evidence of phagocytosis). The tumors identified in this way showed the following histological characteristics: diffuse proliferation of large tumor cells with ample cytoplasm, containing granular or occasionally diffuse diastase resistant PAS positive material, erythrophagocytosis, and haemosiderin pigment. The large or enormous nuclei were irregular, with occasional deep indentations, sharply defined nuclear membrane, coarse chromatin and conspicuous nucleoli. Despite the uniformity of these criteria differences in presence of alpha 1-antitrypsin, alpha 1-antichymotrypsin and 5 Nucleotidase activity and the number of lysosomes in the cytoplasm were found. The findings are suggestive of a spectrum of cytological in these Histiocytic Sarcomas. The clinical picture ranged from monolocalization in a lymphoid organ to that of a diffuse Malignant Histiocytosis. The relationship between good response to therapy and complete remission and the absence of alpha 1-antitrypsin and a high number of lysosomes is discussed.
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PMID:Malignant lymphoma of true histiocytic origin: histiocytic sarcoma. A morphological, ultrastructural, immunological, cytochemical and clinical study of 10 cases. 728 92

True histiocytic lymphoma (THL) and malignant histiocytosis (MH) have been defined by clinical and histologic findings and enzyme histochemistry. We reviewed cases previously diagnosed as cutaneous histiocytic lymphoma (HL) and MH with cutaneous lesions. These cases had been classified as "histiocytic" on the basis of previous enzyme histochemistry profiles of frozen tissue. Cutaneous tumor cells were reevaluated using a panel of immunohistochemical stains in formalin-fixed, paraffin-embedded tissue in correlation with histopathologic examination. The antibodies used in this study were directed against CD45 (leukocyte common antigen [LCA]), CD20 (L26) for B cells, CD3 and CD45RO (UCHL-1) for T cells, CD68 (KP-1) and lysozyme for histiocytes, as well as CD30 (BerH2) for Ki-1 positive cells. On re-evaluation, the seven cases originally classified as HL were reclassified as one case of THL with neoplastic cells positive for CD68 (KP-1) and lysozyme, two cases with immunohistochemical features of Ki-l lymphoma (including one of T-cell lineage), three cases of T-cell lymphoma, and one case of B-cell lymphoma, all associated with variable degrees of reactive histiocytosis. The four cases originally classified as MH were reclassified as two cases of MH and two cases of uncertain lineage. Although rare, histiocytic malignancies do exist. However, the diagnosis of histiocytic malignancy should be made only after careful correlation of atypical tumor cells in histopathologic sections and sections stained immunohistochemically. Erroneous classification of reactive histiocytes as neoplastic histiocytes using only enzyme histochemistry in frozen sections is a pitfall to be avoided.
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PMID:Cutaneous histiocytic malignancy. Immunohistochemical re-examination of cases previously diagnosed as cutaneous "histiocytic lymphoma" and "malignant histiocytosis". 832 Mar 54

True histiocytic lymphoma (THL), as it is currently defined, is a rare entity. We report 12 cases of THL seen at Stanford over the last ten years. By definition, the neoplastic cells in each case showed histological and immunological evidence of histiocytic differentiation. Seven females and five males ranged in age from 9 to 67 years. Sites of involvement included lymph node, soft tissue, bone, stomach, small intestine, mediastinum, kidney, breast and salivary gland. Lymph nodes showed diffuse architectural effacement and/or a paracortical pattern of involvement. The infiltrates involved other tissues in a diffuse pattern. Cytologically the cells were characterized by abundant eosinophilic cytoplasm and enlarged, indented eccentrically placed nuclei containing prominent nucleoli. In all cases the cytological features were sufficiently atypical to indicate a neoplastic infiltrate. Paraffin section immunophenotyping demonstrated reactivity of the atypical cells for CD15, 43, 45RO, 45RB, 68, lysozyme and/or S100. In frozen sections, the atypical cells demonstrated reactivity for CD4 (cytoplasmic), 11c, 14, 15, and/or 68. Genotypic studies were performed on 3 cases, one of which showed rearrangements of immunoglobulin heavy and light chain genes. Follow-up was available on eleven patients, six of whom died of disease 0.5 to 36 months following diagnosis.
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PMID:True histiocytic lymphoma: a study of 12 cases based on current definition. 858 Aug 33

True histiocytic lymphoma is considered a rare entity, and its diagnosis requires the concordance of morphological, immunophenotypic, and molecular findings. The association of malignant lymphoma with tumors in the monocyte-macrophage system has rarely been described. We present a case of mucosa-associated lymphoid tissue (MALT)-type low-grade B-cell lymphoma of the stomach, contiguous to a large tumoral mass that fulfills the morphological criteria (large cells with abundant pale cytoplasm and lobulated or kidney-shaped nuclei) and immunophenotypical features (human leukocyte antigen-DR locus, CD68, S-100, lysozyme immunoreactivity, and negative B- and T-cell markers) required for the diagnosis of histiocytic lymphoma. The patient remains in complete remission 18 months after surgery. The association of low grade-malignant lymphoma with tumors of monocyte-macrophage system cells is an exceedingly rare phenomenon. Whether these tumors are directly related or occur due to pure chance requires the identification of new cases and further study.
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PMID:True histiocytic lymphoma of the stomach associated with low-grade B-cell mucosa-associated lymphoid tissue (MALT)-type lymphoma. 889 46

True histiocytic lymphoma, as defined by strict criteria, is a very rare neoplasm. We describe three cases occurring as primary tumors in the central nervous system. The patients, two females and one male, ranged in age from 11 to 69 years. The tumors involved the brain in two cases and spinal cord in one, with a size ranging from 7 to 17 mm. Two patients died at 4 months and 8 months, respectively, and one was alive with disease at 5 months. Pathologically, the tumors comprised groups and sheets of noncohesive large cells with pleomorphic vesicular nuclei, distinct nucleoli, and abundant eosinophilic cytoplasm. A dense inflammatory infiltrate consisting of neutrophils, lymphocytes, plasma cells, and histiocytes was present, with multiple foci of necrosis and abscess formation. All three cases demonstrated an identical immunophenotype: positive for CD68 and lysozyme; focally positive for S-100 protein, CD45RB, and CD4; and negative for CD3, CD20, CD21/CD35, CD1a, CD30, ALK1, myeloperoxidase, glial fibrillary acidic protein, and cytokeratin. The proliferative index ranged from 20% to 35%. Ultrastructural examination further confirmed the histiocytic nature of the tumor cells, characterized by irregularly folded or multisegmented nuclei and abundant cytoplasm containing lysosomes; Birbeck granules, interdigitating cell processes, and cell junctions were not found. Although the presence of abundant inflammatory cells could obscure the neoplastic histiocytes, making the distinction from inflammatory conditions difficult, awareness of this unusual histologic feature and the invariable finding of pleomorphic cells in some areas of the lesion permit the correct diagnosis to be made.
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PMID:Primary histiocytic lymphoma of the central nervous system: a neoplasm frequently overshadowed by a prominent inflammatory component. 1168 53

Histiocytic sarcoma is a rare malignant neoplasm that occurs in lymph nodes, skin, and the gastrointestinal tract. Many previously published cases were likely misdiagnosed examples of non-Hodgkin lymphoma. Only small numbers of bona fide examples exist in the world literature; cases arising primarily at extranodal sites are not well described and often seem to go unrecognized. To characterize these tumors further, 14 extranodal histiocytic sarcomas were analyzed. Hematoxylin and eosin sections were reexamined, immunohistochemistry was performed, and clinical details were obtained from referring hospitals. Eight patients were female and 6 male (median age, 55 years; range, 15-89 years). All patients presented with a solitary mass, ranging in size from 1.8 to 12 cm (median 6.8 cm). Seven tumors arose in soft tissue (6 lower limb; 1 upper limb), 5 in the gastrointestinal tract (1 involving both stomach and colon, 1 ileum, 2 rectum, 1 anus), 1 in the nasal cavity, and 1 in the lung. Three gastrointestinal tract tumors also involved regional lymph nodes, and 1 involved the liver. Most cases had infiltrative margins. The tumors were generally composed of sheets of large epithelioid cells with abundant eosinophilic cytoplasm, oval to irregular nuclei, vesicular chromatin, and large nucleoli. Binucleated cells were common, and 6 cases contained tumor giant cells. Mitoses ranged from 1 to 64 per 10 HPF (median 11 per 10 HPF). Necrosis was present in 8 cases. Nearly all tumors showed a striking inflammatory infiltrate, most often of neutrophils or lymphocytes. All cases were reactive for LCA, CD45RO, and CD68 (KP1 and PG-M1); 13 of 14 (93%) expressed CD4, 12 of 14 (86%) lysozyme, 8 of 10 (80%) CD31, 7 of 14 (50%) S-100 protein, and 5 of 14 (36%) focal CD1a. Two tumors showed weak, focal cytoplasmic positivity for CD30, and 1 for epithelial membrane antigen. The tumors were negative for ALK-1, CD21, CD35, CD3, CD20, CD34, myeloperoxidase, HMB-45, and keratins. Gastrointestinal tract cases were negative for c-kit and desmin. Six patients were treated with postoperative radiation and 7 with chemotherapy (CHOP or ProMACE-MOPP). Follow-up was available for 10 patients (median, 24 months; range, 4 months to 11 years). Two tumors recurred locally, and 5 patients developed distant spread: 3 to lymph nodes, 1 to lung, and 1 to bone. At the last follow-up, 2 patients have died of disseminated disease, 4 and 5 months following initial diagnosis. The patients who died thus far had the largest primary tumors. Histiocytic sarcoma may arise primarily in soft tissue and shows reproducible histologic features, including abundant eosinophilic cytoplasm and a prominent inflammatory infiltrate. Metastatic carcinoma, metastatic melanoma, and large cell non-Hodgkin lymphomas should be excluded by immunohistochemistry. Histiocytic sarcoma has the potential for an aggressive clinical course, most often with lymph node involvement. However, a subset of cases presenting with clinically localized disease have a favorable long-term outcome. Tumor size may be a prognostic factor.
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PMID:Extranodal histiocytic sarcoma: clinicopathologic analysis of 14 cases of a rare epithelioid malignancy. 1531 12

Histiocytic sarcoma (HS) is a rare but controversial hematopoietic neoplasm. In the past, malignancies have been misclassified as histiocytic tumors due to overlapping histologic features and inadequate phenotypic data. CD163, a recently characterized hemoglobin scavenger receptor, appears to be a 'specific' marker of histiocytic lineage and a promising diagnostic tool for evaluating histiocytic neoplasms. Five cases of HS were studied to further elucidate the clinicopathologic features of these rare tumors and to demonstrate the diagnostic utility of CD163. Criteria for diagnosis included histologic and immunohistochemical evidence of histiocytic differentiation, CD45 positivity, and exclusion of lymphoid, epithelial, melanocytic and dendritic cell phenotype. Sites of disease included the colon (two cases), palate, inguinal lymph node, and testis. The clinical course was aggressive in 4/5 patients (survival=2-15 months). One patient with localized disease of the palate, survived 17 years after diagnosis. All patients with poor survival had tumors > or =3.5 cm. Histologically, all cases showed diffuse architecture with large, discohesive polygonal cells. Spindling of cells was focally noted. Hemophagocytosis was identified in 3/5 cases. A prominent inflammatory background was present in 4/5 tumors. All cases were immunoreactive for CD45, CD163, CD68, and lysozyme. S-100 was focally positive in 4/5 cases. Antibodies for melanocytic, epithelial, lymphoid, and dendritic cell markers were negative. Molecular studies showed monoclonal IgH gene rearrangements in three cases. Our findings suggest that HS is an uncommon neoplasm frequently extranodal in presentation and aggressive in behavior, with rare exceptions. Stage of disease and possibly tumor size are significant prognostic indicators. Molecular studies remain controversial in the diagnosis. The morphologic and phenotypic features are relatively uniform; however, the diagnosis requires exclusion of more common neoplasms by extensive immunophenotypic studies. CD163 appears to be a specific histiocytic marker and is important in establishing the diagnosis of HS.
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PMID:Histiocytic sarcoma: a study of five cases including the histiocyte marker CD163. 1569 28

This is the first case report of Histiocytic Sarcoma (HS) with predominant spindle cell component occurring in the head and neck region of a 41-year-old man. The tumor was composed of sheets of large round to oval cells with pleomorphic vesicular nuclei, prominent nucleoli and abundant eosinophilic cytoplasm. Multinucleated forms, numerous mitoses, and tumor necrosis were also noted. Sheets, fascicles, and whorls of spindle cells with spindled to ovoid vesicular nuclei, small to medium-sized distinct nucleoli, and eosinophilic cytoplasm were frequently observed. Immunohistochemical staining in the tumor cells was positive for CD163, CD68, lysozyme, CD45, and NSE. Focal expression of CD4 and S-100 was also noted. Electron microscopy demonstrated an abundance of lysosomes in the cytoplasm of tumor cells. Chromosome study revealed a 57-80 hyperdiploid [7]/46, XY [13] karyotype, including 3 to 4 copies of various chromosomes. The immunohistochemical and ultrastructural findings confirmed the diagnosis of HS.
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PMID:Primary histiocytic sarcoma arising in the head and neck with predominant spindle cell component. 1732 77

Histiocytic sarcoma is an uncommon neoplasm of mature histiocytes with a poor clinical outcome. We report a case of a true histiocytic sarcoma with prominent and evenly distributed multinucleated giant cells that mimics a giant cell tumor of soft tissue. The tumor was located between the appendix, right ovary, and the terminal ileum with severe adhesion. The liver and spleen were not enlarged. Grossly, the tumor appeared grayish white, solid, and soft. Microscopically, polygonal mononuclear tumor cells aggregated to form somewhat epithelioid nests, which occasionally showed coagulative necrosis. Prominent and evenly scattered giant cells were present in all sections. In addition, tumor cell infiltration was noted in regional lymph nodes. The tumor cells were positive for lysozyme, CD68, CD163, and negative for T- and B-cell lineage markers, follicular dendritic cell, megakaryocytic, epithelial, muscular, and melanocytic markers, CD1a and CD30. This case posed great difficulty in clinical and pathological diagnoses. Gross pictures, microscopic findings, and extensive immunostains are important for the differential diagnosis.
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PMID:Histiocytic sarcoma - a case with evenly distributed multinucleated giant cells. 1767 73

Histiocytic sarcoma is the most frequent hematopoietic tumor in rats. We report here a histiocytic sarcoma infiltrating the liver, the spleen and the pancreas from a Wistar rat. In the liver, the tumor was associated with oval cell and bile duct hyperplasia. The cells looked like neoplastic histocytic cells described in this species but with some particularities (e.g. lack of multinucleated giant cells). At immunohistochemistry, neoplastic cells in the liver were vimentine positive but lysozyme and CD68 negative. In the kidney, lysozyme-positive cytoplasmic droplets were observed. We describe here an atypical case of histiocytic sarcoma in the rat and we compare the nature of these neoplastic cells to other species.
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PMID:An atypical case of histiocytic sarcoma in a Wistar rat (Rattus norvegicus). 1822 80


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