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)

Four cases of acute myelofibrosis are contrasted to three cases of acute megakaryocytic leukemia. The cases were clinically indistinguishable. Light microscopic examination of hematoxylin and eosin-stained bone marrow biopsy specimens from the cases of acute myelofibrosis showed a trilinear proliferation of mature and immature hematopoietic cells, increased numbers of mature magakaryocytes, and marked fibrosis. In contrast, the blast cells in the cases of acute megakaryocytic leukemia showed a continuous spectrum of differentiation from small blasts to megakaryoblasts. Immunoperoxidase staining showed the blast cells in all three cases of acute megakaryocytic leukemia to be strongly positive for Factor VIII, a marker of megakaryocytic differentiation. These same blasts did not stain with markers of myelomonocytic (lysozyme), lymphocytic (Hle), and myeloid (Leu-Ml) differentiation. In contrast, the blast cells in all four cases of acute myelofibrosis were Factor VIII, Hle, and Leu-Ml negative but did occasionally stain with anti-lysozyme.
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PMID:Acute myelofibrosis. Immunohistochemical study of four cases and comparison with acute megakaryocytic leukemia. 331 70

This report presents the interesting case of a 50-year-old white man with an unusual benign tumor composed predominantly of a proliferation of atypical endothelial cells combined with a variable inflammatory response. This case represents an instance of the recently renamed entity "histiocytoid hemangioma" in which two organ systems are involved. Both skin and bone showed typical lesions. No physical connection jointed the separate lesions. The results of examination by light microscopy, electron microscopy, and immunoperoxidase examination for lysozyme and Factor VIII are reported. The significance of this case is that it supports the concept of classifying similar vascular lesions, despite varied organ system origin, into a single entity, the histiocytoid hemangioma.
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PMID:Histiocytoid hemangioma of the skin and scapula. A case report with electron microscopy and immunohistochemistry. 640 16

A case of angiolymphoid hyperplasia (AHE) with eosinophilia presenting with recurrent inguinal swellings simulating lymphadenopathy is described. Tissue was examined by light microscopic techniques, electron microscopy and immunohistochemistry. Electron microscopy showed large numbers of cytoplasmic filaments and bizarre Weibel-Palade bodies in the atypical endothelial cells that characterize AHE. Factor VIII related antigen was demonstrated in a small proportion of these cells by immunoperoxidase staining. The absence of staining for lysozyme and alpha 1 antitrypsin does not support the concept that these cells are histiocytic in nature. The prominent lymphoid and plasma cell proliferative elements in this case showed a polytypic staining pattern for immunoglobulin. An unusual reticular staining pattern for IgE was observed in the lymphoid follicles. The nature and pathogenesis of AHE is discussed in the light of previous publications and the findings in this case.
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PMID:Angiolymphoid hyperplasia with eosinophilia simulating lymphadenopathy. 678 2

This report describes a case of a malignant vascular tumor of the spleen with the morphologic, immunologic, and ultrastructural features observed in splenic sinus-lining cells (littoral cells). Histological examination showed a well-differentiated neoplasm forming ectatic blood channels with intraluminal papillary fronds. Tumor cells displayed malignant nuclear features and hemophagocytosis. Solid neoplastic areas with mitotic figures were present. Ultrastructurally, the tumor cells showed the concomitant presence of lysosomes and Weibel-Palade bodies. Immunohistochemically, the tumor cells were positive for both endothelial (Factor VIII-AG, CD34) and histiocytic markers (cathepsin D, lysozyme, alpha-1-antichimotrypsin). Our results indicate that angiosarcoma may originate from all the vascular compartments of the spleen, including red-pulp sinuses, and may have morphologic and immunophenotypic similarities to littoral cell angioma, a recently described benign vascular tumor of the spleen.
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PMID:Littoral cell angiosarcoma of the spleen. Case report with immunohistochemical and ultrastructural analysis. 757 79

Few published reports describe patients with giant cell fibroblastoma, a rare, benign soft-tissue tumor that recurs locally and predominantly arises in children. A 4-year-old boy underwent surgery for removal of a giant cell fibroblastoma in the paranasal region, an unusual site. Six months after excision the tumor recurred locally. Immunohistochemical examination of the primary tumor and recurrence revealed vimentin positive staining in the cytoplasm of all the cells. The multinucleated giant cells and the flat cells bordering the vessel-like spaces were negative for Factor VIII-related antigen, S-100 protein, actin and desmin. Some histiocytes stained positively for alpha-1-antitrypsin, alpha-1-antichymotrypsin, antimacrophage and lysozyme antibodies. These immunoreactions indicate that giant cell fibroblastomas have a fibrohistiocytic origin.
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PMID:Paranasal giant cell fibroblastoma: case report and immunohistochemical findings. 804 95

Immunohistochemical and ultrastructural studies were performed on the sinusoidal lining cells of eight canine hepatocellular carcinomas. The sinusoidal endothelial cells of the tumors had a positive reaction for both Factor VIII-related antigen and peanut agglutinin, but did not bind with Ulex europaeus agglutinin-1. Desmin- and lysozyme-positive cells were present along the sinusoids and perisnusoidal spaces of the tumor tissues, respectively, but were fewer in number compared with those of normal canine liver. Alpha-Smooth muscle actin-positive cells outlining the sinusoids were frequently observed. Electron microscopy revealed that basement membranes were often formed beneath the sinusoidal endothelial cells, with rare fenestration. Macrophages were present around or within the sinusoids and tended to increase in number relative to the degree of tumor differentiation. Myofibroblast-like cells with various morphological features, consistent with alpha-smooth muscle actin-positive cells, were frequently found in the perisinusoidal space. The present study indicates that the sinusoidal lining cells of canine hepatocellular carcinoma have some phenotypic characteristics.
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PMID:Immunohistochemical and ultrastructural studies on the sinusoidal lining cells of canine hepatocellular carcinoma. 889 92

We herein describe two unusual neoplasms showing histopathologic features consistent with those of giant cell angiofibroma, which was originally described as a neoplasm arising in the orbit in adults: one of them arose in the right submandibular region of a 48-year-old woman and the other in the right parascapular region of a 49-year-old woman. Macroscopically, although the latter was characterized by a lymphangioma-like cystic appearance, both tumors were well circumscribed and encapsulated. Microscopically, in both cases, pseudovascular spaces lined by a discontinuous row of multinucleated cells were seen against a background of spindle-shaped fibroblastic cell proliferation. In the second case, the tumor presented increased cellularity and plump and somewhat atypical nuclei of proliferating fibroblastic cells, compared with the tumor in the first case. Immunohistochemically, the mononuclear and multinucleated cells within these tumors were positive for vimentin and CD 34 but negative for any other antigens, including Factor VIII-related antigen, desmin, alpha smooth muscle actin, myoglobin, S-100 protein, LeuM1, lysozyme, alpha-1-antitrypsin, and cytokeratins (AE1/AE3 and CAM5.2). The features in these cases indicate that giant cell angiofibroma can arise in an extraorbital site in middle-aged patients and presents some histopathologic diversity.
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PMID:Extraorbital giant cell angiofibromas. 938 57

Interdigitating dendritic cell sarcoma is an extremely rare neoplasm that mainly occurs in the lymph nodes. We report a case of interdigitating dendritic cell sarcoma arising from the spleen, a previously unreported site for interdigitating dendritic cell sarcoma. An 87-year-old woman, visiting Ashigara Hospital with complaints of palpitation and dyspnea, was found to have pancytopenia and low proteinemia. Abdominal ultrasonography and CT scanning demonstrated severe splenomegaly with heterogeneous enhancement. She received a splenectomy under the clinical diagnosis of a splenic tumor. Grossly, the spleen was markedly enlarged, with confluent massive nodules. Microscopically, the normal architecture was effaced with diffuse proliferation of large pleomorphic cells arrayed in a somewhat sheet-like pattern. Erythrophagocytosis was commonly observed. Immunohistochemical studies showed that the tumor cells were positive for S-100 protein, fascin, vimentin, and CD68, but uniformly negative for CD45, B- and T-cell markers, CD1a, CD30, complement receptors, CD34, Factor VIII, HMB-45, and lysozyme. Ultrastructurally, the tumor cells possessed complex interdigitating cytoplasmic dendritic processes. Birbeck granules were absent. Based on these findings, the present case was diagnosed as interdigitating dendritic cell sarcoma. The patient died of multiple liver metastases 3 months postoperatively.
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PMID:Interdigitating dendritic cell sarcoma of the spleen: report of a case with a review of the literature. 1191 34

The present paper describes an astrocytic thalamic hamartoma associated with tectal meningoangiomatosis in a 3-month-old female German shepherd dog showing strabismus, opistotonus, circling, and fore limb hypermetria. MR images of the brain showed a well-defined intra-axial mass in the tectal region. The mass was hypointense to gray matter on T2-weighted images and hyperintense to gray matter on precontrast T1-weighted images. Histologically, glial cells arranged in a multinodular pattern characterized the mass. More caudally the lesion merged with subpial abnormal newly formed plaque-like shaped tissue characterized by thick branching bundles of spindle-shaped cells surrounding a central vessel. In the nodules, GFAP and vimentin were diffusely expressed. In the vascular proliferation Factor VIII-positive reaction was limited to endothelial cells while the remaining spindle-shaped cells were diffusely SMA-positive. The glial nodules did not express lysozyme and MAC387, nor neurofilaments and nestin.
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PMID:Thalamic astrocytic hamartoma and associated meningoangiomatosis in a German shepherd dog. 2326 Nov 50


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