Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0019621 (Langerhans cell histiocytosis)
 3,250 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In order to determine the antigenic phenotype of the proliferating cells in Langerhans cell histiocytosis (LCH), we studied 15 such examples by using formalin- and B5-fixed, paraffin-embedded tissues. We used a panel of antibodies that are known to react with lymphocyte- and histiocyte-associated antigens. These included LN-1, LN-2, and LN-3 monoclonal antibodies (MoAbs), MoAbs to leukocyte common antigen (LCA), Leu-M1 antigen, vimentin, and epithelial membrane antigen (EMA), as well as polyclonal antibodies to lysozyme and S100 protein. The antigens encountered most frequently in LCH cells were S100 protein (93% of cases), vimentin (86%), and those detected by LN-2 (80%) and LN-3 (82%). Lysozyme was detected focally in two cases and diffusely in one case. The LCH cells were negative for LN-1, LCA, Leu-M1, and EMA. There was only one specimen in which S100 protein was not demonstrated; in this case, LN-3, vimentin, and T6 on frozen section were positive. The phenotype of LCH cells is similar to that of Langerhans' cells and interdigitating histiocytes. Our results demonstrate the value of using a panel of antibodies, including anti-vimentin MoAb, LN-2, and LN-3 for the immunophenotypic diagnosis of LCH in addition to an antibody to S100 protein.
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PMID:Antigenic phenotype of Langerhans cell histiocytosis: an immunohistochemical study demonstrating the value of LN-2, LN-3, and vimentin. 297 28

As the use of endoscopic biopsy has increased in recent years, the pathologists whose job it is to interpret these small specimens have been asked to give more specific diagnoses. Plastic embedding has proved to be a useful diagnostic tool because it provides better morphology than routine paraffin embedding and because enzyme histochemical and immunohistochemical markers can be used. We applied these techniques to endoscopic biopsies hoping to increase the diagnostic yield. Biopsies from 75 patients were fixed in paraformaldehyde, embedded in methacrylate, and sectioned at 2 mu. These sections were then compared with routine sections from the same patient. Additional special stains were used and enzyme histochemistry, or immunohistochemistry was performed on the plastic- or paraffin-embedded tissue as needed. We found that in 26.7% of the cases, plastic sections resulted in more specific diagnoses than was possible with paraffin sections. When distinguishing lymphomas from poorly differentiated carcinomas, this method provided much better morphologic differentiation and better demonstration of leukocyte common antigen than keratin staining. Identification of B- or T-cell antigens was possible on plastics but not on paraffin. Furthermore, lesions such as histiocytosis X and cryptosporidiosis were more accurately identified. Thus, we found that the plastic-embedded tissue provided all the information yielded by routine paraffin embedding and also improved the diagnostic yield on certain types of neoplastic or infectious processes.
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PMID:Plastic-embedded endoscopic biopsies. Diagnostic advantages. 338 52

A 64-year-old male farmer presented with a rapidly progressive swelling of the left mandible since 6 months. The swelling was firm to hard, diffuse, nontender, obliterating the vestibule with paresthesia of lower lip. The cone beam computed tomography imaging revealed an ill-defined, moth-eaten radiolucency with destruction of the buccal and lingual cortical plates. The rapid growth and aggressive behavior of the lesion coupled with guidance from the patient's previous reports from the incisional biopsy and fine needle aspiration cytology warranted a mandibular resection. Microscopic examination showed an encapsulated lesion situated in the connective tissue containing a mixture of proliferating spindle-shaped cells arranged in fascicles and round cells infiltrating into the connective tissue stroma and bone. The neoplastic cells exhibited atypical features such as pleomorphism, hyperchromatism and increased mitotic figures with noncleaved nuclei. A working diagnosis of a spindle-cell sarcoma was arrived at with various differentials provided such as fibrosarcoma, rhabdomyosarcoma, leiomyosarcoma, malignant peripheral nerve sheath tumor, Langerhans cell histiocytosis and lymphoma and stating the need for immunohistochemistry to subtype the tumor. The neoplastic cells were negative for Van Gieson's stain and Masson's trichrome. Immunohistochemical analysis performed using desmin, smooth muscle actin, S-100 and CD1a in a bid to determine the phenotype of the tumor and rule out the previously stated differentials were all negative for the lesion. Lymphoid markers such as leukocyte common antigen and CD20 (cluster differentiation marker for B-cells) showed positivity in spindle-shaped cells as well as round cells indicating the tumor to be a lymphoproliferative lesion of B-cell type. A final diagnosis of "spindle-cell variant of non-Hodgkin's lymphoma" was rendered based on the immunohistochemical profile.
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PMID:A rare spindle-cell variant of non-Hodgkin's lymphoma of the mandible. 2719 75