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)

Neoplasms of histiocytes and dendritic cells are rare, and their phenotypic and biological definition is incomplete. Seeking to identify antigens detectable in paraffin-embedded sections that might allow a more complete, rational immunophenotypic classification of histiocytic/dendritic cell neoplasms, the International Lymphoma Study Group (ILSG) stained 61 tumours of suspected histiocytic/dendritic cell type with a panel of 15 antibodies including those reactive with histiocytes (CD68, lysozyme (LYS)), Langerhans cells (CD1a), follicular dendritic cells (FDC: CD21, CD35) and S100 protein. This analysis revealed that 57 cases (93%) fit into four major immunophenotypic groups (one histiocytic and three dendritic cell types) utilizing six markers: CD68, LYS, CD1a, S100, CD21, and CD35. The four (7%) unclassified cases were further classifiable into the above four groups using additional morphological and ultrastructural features. The four groups then included: (i) histiocytic sarcoma (n=18) with the following phenotype: CD68 (100%), LYS (94%), CD1a (0%), S100 (33%), CD21/35 (0%). The median age was 46 years. Presentation was predominantly extranodal (72%) with high mortality (58% dead of disease (DOD)). Three had systemic involvement consistent with 'malignant histiocytosis'; (ii) Langerhans cell tumour (LCT) (n=26) which expressed: CD68 (96%), LYS (42%), CD1a (100%), S100 (100%), CD21/35 (0%). There were two morphological variants: cytologically typical (n=17) designated LCT; and cytologically malignant (n=9) designated Langerhans cell sarcoma (LCS). The LCS were often not easily recognized morphologically as LC-derived, but were diagnosed based on CD1a staining. LCT and LCS differed in median age (33 versus 41 years), male:female ratio (3.7:1 versus 1:2), and death rate (31% versus 50% DOD). Four LCT patients had systemic involvement typical of Letterer-Siwe disease; (iii) follicular dendritic cell tumour/sarcoma (FDCT) (n=13) which expressed: CD68 (54%), LYS (8%), CD1a (0%), S100 (16%), FDC markers CD21/35 (100%), EMA (40%). These patients were adults (median age 65 years) with predominantly localized nodal disease (75%) and low mortality (9% DOD); (iv) interdigitating dendritic cell tumour/sarcoma (IDCT) (n=4) which expressed: CD68 (50%), LYS (25%), CD1a (0%), S100 (100%), CD21/35 (0%). The patients were adults (median 71 years) with localized nodal disease (75%) without mortality (0% DOD). In conclusion, definitive immunophenotypic classification of histiocytic and accessory cell neoplasms into four categories was possible in 93% of the cases using six antigens detected in paraffin-embedded sections. Exceptional cases (7%) were resolvable when added morphological and ultrastructural features were considered. We propose a classification combining immunophenotype and morphology with five categories, including Langerhans cell sarcoma. This simplified scheme is practical for everyday diagnostic use and should provide a framework for additional investigation of these unusual neoplasms.
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PMID:Tumours of histiocytes and accessory dendritic cells: an immunohistochemical approach to classification from the International Lymphoma Study Group based on 61 cases. 1212 Dec 33

Langerhans cell sarcoma (LCS) is a rare but potentially life-threatening neoplastic condition. The diagnosis of LCS requires morphological and immunophenotypic characterization to distinguish it from other epithelioid-appearing malignancies. Four cases of LCS were encountered in the consultative practices of 2 of the authors. The patients ranged in age from 54 to 88 years of age. In 2 of the cases the patients had a history of acute myelogenous leukemia with eruptions occurring after initiation of decitabine. One patient died within 3 months of presenting with the skin eruption, whereas the other patient is in remission. In the other 2 patients, there was no antecedent history; the presentation was in the context of a solitary nodule. One patient declined treatment and died of disseminated metastatic disease. The other patient had complete excision with no evidence of recurrent or metastatic disease. In all cases, the biopsies showed a sheet-like growth of large atypical epithelioid cells. Phenotypic studies revealed positivity for CD4, CD1a, and S100 in all and variable staining for langerin, lysozyme, CD83, CD31, and CD14. Cutaneous LCS represents a terminally differentiated myeloid tumor with a variable but potentially aggressive clinical course. It may be related to a common stem cell defect given the association with acute leukemia. The morphology ranges from atypical appearing Langerhans cell to a high-grade large cell epithelioid malignancy mimicking amelanotic nodular melanoma.
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PMID:Primary cutaneous langerhans cell sarcoma: a report of four cases and review of the literature. 2305 26

We present the case of a 62-year-old male patient with a three-month history of pain in the left shoulder. Magnetic resonance imaging of the left scapula showed an osteo-destructive lesion. H and E stained sections revealed a Langerhans cell sarcoma, and immunohistochemistry was performed additionally; CD68, CD163, CD14, fascin, HLA-DR, lysozyme, S100 CD1a and langerin showed a positive reaction, while CD20, CD30, CD34, CD31, pan-cytokeratin, AE/1AE3, SMA, desmin, EMA, ERG, INI-1, CD21, CD4, PLAP, MPO and CD117c were negative. We suggested palliative treatment with chemotherapy and radiation. The patient refused any treatment and died 2 weeks later.
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PMID:Langerhans cell sarcoma: a case report and review of the literature. 2754 73