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)

Seventeen meningeal tumors were examined for pathology with electron microscopy and immunohistochemistry including glial fibrillary acidic protein (GFAP), S-100 protein, muramidase, and factor VIII. These tumors included seven meningiomas, one hemangiopericytoma, three meningeal sarcomas (1 pleomorphic-cell type and 2 myxofibrosarcomas), two fibrous histiocytomas, and four malignant melanomas. Two of seven children with meningioma had a poor outcome despite the benign histological features of the tumor. S-100 protein was present in the two tumors. All three children with meningeal sarcoma had a rapid downhill clinical course, although the myxofibrosarcoma initially had a relatively benign histological appearance. The two children with fibrous histiocytoma did well despite the aggressive histological features. Muramidase was a good marker of such tumors. Because of the morphological difficulties associated with childhood meningeal tumors, both electron microscopy and immunohistochemistry can be of diagnostic benefit.
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PMID:Meningeal tumors of infancy and childhood. 300 8

Two patients with inflammatory meningeal masses were studied. Lesions in both patients showed varying proportions of meningothelial and inflammatory components. The non-neoplastic nature of the inflammation was confirmed in one case by lymphocyte surface marker study, which showed T and B cells in one to four ratio, and by immunohistochemistry, which revealed polyclonal plasma cells. The abundant histiocytes contained muramidase and often enclosed intact lymphocytes or plasma cells within their cytoplasm, i.e., emperipolesis. Their surfaces bore slender interdigitating pseudopodia, intercellular junctions, and subplasmalemmal linear densities. The derivation of these histiocytes is uncertain: mononuclear phagocytes, meningothelial cells, and multipotential meningeal cells are all possible progenitors. A comparison with eleven similar reported cases reveals a tendency for inflammatory meningeal masses to occur in the young, as well as a predilection for posterior fossa involvement. They resemble the extranodal lesions of sinus histiocytosis with massive lymphadenopathy, as well as plasma cell granulomas or inflammatory pseudotumors of lung and other tissues. However, it is possible that these lesions represent a variant of meningioma in which an unusual immunological response has been evoked.
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PMID:Inflammatory meningeal masses of unexplained origin. An ultrastructural and immunological study. 686 38

In a retrospective study, granular cell tumors in six dogs (Nos. 1-6), three cats (Nos. 1-3), one horse (No. 1), and one cockatiel (Nymphicus hollandicus) (No. 1) and a meningioma with a granular cell component in one dog (No. 7) were examined histologically and immunohistochemically. These tumors were identified by histologic examination of surgical biopsy specimens, except in the horse, in which the tumor was an incidental finding at necropsy. These diagnoses were initially made by more than one pathologist. Five of the six granular cell tumors in the dogs were in the oral cavity; one of these was in the maxillary gingiva of a 6-month-old puppy. The tumors in the cats were located in the tongue, vulva, and digit. The tumor in the horse was in the lung, and the tumor in the cockatiel was in the periocular tissue. Histologically, all granular cell tumors were characterized by oval to polygonal cells of various sizes. The cells had abundant, pale, eosinophilic cytoplasm with distinct intracytoplasmic granules, distinct cell margins, and mostly central nuclei. In the dogs, the gingival tumor had a large amount of collagen tissue, the tumor in the tongue had dilated blood vessels, and the maxillary tumor in the puppy was more cellular than the other tumors. The tumors in the cats were more anaplastic than the other tumors; one, located in the digit, was considered malignant. The granules in all of the tumors stained with periodic acid-Schiff and were diastase resistant. On staining with Luxol fast blue, the granules of all tumors stained different shades of pink, with the exception of the tumor in the tongue of a cat, which stained bluish green. Immunocytochemically, all tumors except the tumor in the cockatiel reacted against antibodies to vimentin. The granular cell tumor in the lung of the horse and the intracranial meningioma in a dog reacted to the antibody S-100 protein; the tumor in the horse reacted to neuron-specific enolase; tumors in two dogs (gingiva and skin) reacted to L-antitrypsin, and the maxillary tumor also reacted to lysozyme; the malignant tumor in the digit of a cat and the periocular tumor in the cockatiel reacted to muscle common actin and actin; the tumor in the cockatiel also reacted to desmin. Results of these immunocytochemical studies suggest that granular cell tumors, like tumors composed of rhabdoid cells, clear cells, and oncocytes, can have similar morphologic features but be of different cellular origins.
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PMID:Histologic and immunohistochemical studies of granular cell tumors in seven dogs, three cats, one horse, and one bird. 847 Mar 38

The light microscopic and ultrastructural appearances of unusual filamentous aggregates in a right parietal meningioma in a 14-year-old boy are described. The tumor showed prominent meningothelial as well as fibroblastic components and was graded as an atypical meningioma. By light microscopy, eosinophilic, PAS-positive, granular, irregularly shaped Rosenthal fiber-like structures were widespread within the tumor, in both an intra- and an extracellular location. By immunohistochemical staining, similar location of positivity was obtained for vimentin, laminin, and collagen type IV. The inclusions were nonreactive for keratin, lysozyme, alpha-1-antitrypsin, and ubiquitin. Ultrastructurally, these aggregates were composed of an irregular tangle of filaments with electron dense condensations, sometimes with a lattice pattern. The intracellular aggregates were membrane-bound, and some were found within dilated rough endoplasmic reticulum, while extracellularly, they filled up spaces between adjacent tumor cells. Less prominently, flocculent osmiophilic nonfilamentous material was also seen within the inclusions. These observations suggest that these novel inclusions in a meningioma are composed of intermediate filaments (vimentin) and extracellular matrix proteins, with active synthesis in the rough endoplasmic reticulum and subsequent extrusion from the tumor cells into the extracellular spaces.
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PMID:Filamentous aggregates in a meningioma. 894 Jul 65

We report a case of myeloid sarcoma of the brain mimicking a meningioma on CT scan. The lesion was first morphologically misdiagnosed as a lymphoma, but correctly identified by using immunochemistry with anti-myeloperoxidase, anti-CD68, anti-CD15 antibodies. An acute myeloid leukemia was diagnosed 5 months later. Myeloid sarcoma is frequently mistaken for malignant lymphoma, especially when it presents without leukemic manifestation, even at immunohistochemistry, since both express some leukocyte antigens. Careful evaluation of morphology for evidence of myeloid differentiation, and immunohistochemistry using anti-myeloperoxidase, anti-lysozyme, CD15, CD68 antibodies, should be used to confirm the diagnosis and to rule out lymphoma since the treatment is different.
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PMID:[Myeloid sarcoma of the brain. A case report]. 1274 2

We report a case of metaplastic meningioma with extensive xanthomatous change occurring in a 61-year-old woman. Magnetic resonance imaging demonstrated a well-demarcated, dura-based mass measuring 7 cm in maximal diameter in the right occipital to parietal area. Under a clinical diagnosis of meningioma, right parietal craniotomy was performed. Histologically, the tumor showed extensive xanthomatous change together with the common features of meningothelial meningioma. Tumor cells showed diffuse xanthomatous change in various quantities, and xanthomatous tumor cells frequently showed a gradual transition to the non-xanthomatous counterpart. The xanthomatous tumor cells showed immunopositivity for epithelial membrane antigen (EMA), vimentin, fatty acid synthase and several histiocytic markers (CD68, Ki-M1p, MAC387, lysozyme, alpha 1-antitrypsin and alpha 1-antichymotrypsin). In addition, there was patchy infiltration of foamy macrophages. Since these histiocytes did not show immunopositivity for EMA, these cells were distinguished from the xanthomatous tumor cells. These two types of xanthomatous changes comprised approximately two-thirds of the whole tumor tissue. Any atypical features such as necrosis, frequent mitotic figures or brain parenchymal invasion were not observed. We diagnosed this case as xanthomatous meningioma, WHO grade I.
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PMID:A case of metaplastic meningioma with extensive xanthomatous change. 1841 Feb 75

Granulocytic sarcoma (GS) is a rare solid tumor of myeloid origin, which usually precedes or occurs concurrently with myeloid leukemia, or with other types of myeloproliferative and myelodysplastic disorders. Spinal affections of GS have been described but are uncommon, particularly in association with essential thrombocythemia. We present a case of a 75-year-old woman with a long history of essential thrombocythemia who developed 2 tumors: 1 in the bodies of T3 - 6 vertebras extending epidurally, and the other in the right frontal lobe, adherent to dura, thus, mimicking meningioma. The patient died because of massive pulmonary thrombembolia. Microscopical and immunohistochemical features of spinal and intracranial tumor samples obtained at autopsy were consistent with the diagnosis of GS with focal megakaryocytic differentiation. Clinicians and pathologists should be aware of this rare tumor being so diverse in its clinical presentation, as well as in microscopical and immunohistochemical features. Careful evaluation of morphology, in conjunction with immunohistochemistry for evidence of myeloid differentiation are required to avoid frequent errors in diagnostics of GS. The suggested panel includes chloroacetate esterase, myeloperoxidase, lysozyme, CD117, CD43, CD79a and CD3. Only early correct diagnosis will enable proper treatment which may be successful despite the highly malignant potential of GS.
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PMID:Granulocytic sarcoma in a patient with essential thrombocythemia presented as acute spinal cord compression--case report and review of the literature. 1866 40

Follicular dendritic cell sarcoma (FDCS) is a low-grade malignant neoplasm that tends to be under-recognized owing to its rarity and wide pathologic spectrum. Knowledge of the atypical morphology and immunophenotype of FDCS is critical to avoid misdiagnosis. Here we presented a case of extranodal FDCS with an unusual morphology and a previously unreported immunophenotype leading to misdiagnosis. A 32-years-old man presented with a tonsilar mass that showed epithelioid cells in nested and alveolar patterns. Immunohistochemistry study revealed that the tumor cells were positive for CD4 and CD30, and were negative for cytokeratin, CD3, CD20, CD68, CD163, lysozyme, ALK, S-100, and desmin. Multiple outside expert consultations rendered a consensus diagnosis of ALK-negative anaplastic large cell lymphoma (ALCL). The patient received multiple lines of chemotherapy and radiotherapy. However, the residual tumor progressively enlarged eight months later and a more complex morphology was presented in the re-excised tumor: including spindle cells with vesicular nuclei and nuclear pseudoinclusions in fascicles or a whorled pattern, and plump ovoid cells arranged in meningioma-like whorls as well as epithelioid tumor cells similar to the initial biopsy. All these three components were positive for CD4, CD21, CD23, and CD35. The diagnosis was revised to FDCS after a positive immunostaining for CD21, CD23, and CD35 on the initial specimen was confirmed retrospectively. A literature review identified 57 cases of FDCS published from 2009 through 2019, and 13 (22.8%) of them were misdiagnosed at initial presentation. Among these misdiagnosed cases, all except one case were extranodal, and the incorrect initial diagnosis was mostly location-related. These cases expand the pathologic spectrum of FDCS, and further emphasize the necessity for pathologists to stay alert for this rare entity, bringing FDCS into the differentials for any spindle cell tumors, undifferentiated epithelioid cell tumors, and ALCL to avoid misdiagnosis.
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PMID:Follicular Dendritic Cell Sarcoma With Co-Expression of CD4 and CD30 Mimics Anaplastic Large Cell Lymphoma. 3254 56