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Query: UMLS:C0019621 (Langerhans cell histiocytosis)
 3,250 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Langerhans cell histiocytosis (LCH) is a neoplastic proliferation of Langerhans cells that occurs in a range of nodal and extranodal sites. Scattered reports of LCH within the thymus exist, typically among children within the setting of multifocal, multisystem disease. Rare cases of isolated LCH involving the thymus have occurred in adult patients with myasthenia gravis. We report a case of unifocal LCH involving the thymus in a middle-aged woman with a history of a resected leiomyosarcoma but no evidence of myasthenia gravis. Computed tomographic scans revealed an anterior mediastinal mass, which was excised and measured 9.0 cm. Histologic and immunophenotypic findings (CD1a, S100, and Fascin positive and CD68 negative) were consistent with LCH. To our knowledge, this is the first example of LCH occurring in a patient with a history of soft tissue sarcoma and one of the rare reported examples of LCH presenting as a large isolated lesion in the thymus of a nonmyasthenic adult.
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PMID:Langerhans cell histiocytosis involving the thymus. A case report and review of the literature. 1282 60

Malignant Langerhans cell tumor is a rare malignant proliferation of Langerhans cells, with a negative prognosis due to its dissemination throughout the body, leading to death within 1 year. This disease has to be distinguished from Langerhans cell histiocytosis. The favorable evolution of a case of Langerhans cell tumor, characterized by the absence of metastasis 18 months after its occurrence, may be due to the initial treatment, which consisted of complete and large resection of the tumor. The authors searched for abnormal dendritic cells or progenitors in the blood but found no large amounts or proliferation of CD34(+) or CD1a(+) cells at the diagnosis and 1 year later. This case report shows that malignant Langerhans cell tumor is not always a lethal disease. The condition may be related to surgical treatment and the absence of malignant cells in the blood when the diagnosis was performed.
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PMID:Malignant Langerhans cell tumor: a case with a favorable outcome associated with the absence of blood dendritic cell proliferation. 1296 24

A 42-yr-old woman was referred to our hospital because of multiple small nodules in a chest radiograph. She had no symptoms such as dyspnea, cough or sputum. A chest CT revealed many centrilobular small nodules and thin-walled cysts with predominance in the peripheral area of the lungs. The specimens obtained by thoracoscopic surgery showed granulomas with scattered eosinophils and numerous Langerhans' cells. The Langerhans' cells were positive for both S-100 protein and CD1a. These findings are compatible with pulmonary Langerhans' cell histiocytosis (LCH). Since the granulomas showed no fibrotic changes, the LCH may have been in its early stages. However, there were clusters of lymphocytes and macrophages around the terminal and respiratory bronchioles, and cystic lesions without cellular infiltrates, in the specimens. The former histologic findings suggested respiratory bronchiolitis causing interstitial lung disease and the latter are indistinguishable from centrilobular emphysema. Therefore, these smoking-related diseases may have been superimposed on the LCH in this patient.
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PMID:[A case of pulmonary Langerhans' cell histiocytosis]. 1453 8

Histiocytoses are diseases caused by proliferation of either dendritic cells/Langerhans cells or of monocytes/macrophages. Generalized eruptive histiocytosis belongs to the cutaneous non-Langerhans cell histiocytoses and is a rare monocyte-macrophage proliferative disorder that usually follows a benign clinical course. We present the case of a 59-year-old man who presented with a 7-month history of progressively developing erythematous macules and slightly elevated papules widely distributed over the trunk, neck, face, and thighs. Ultrastructurally, no Birbeck granules were observed, and immunochemistry did not reveal any S-100 protein or CD1a antigen in any of the lesional cells, excluding Langerhans cell histiocytosis. In addition, the histiocytic infiltrate in the skin of our patient was shown to strongly express MS-1 high molecular weight protein, a marker described as highly characteristic for cutaneous non-Langerhans cell histiocytoses. Bone-marrow smear examination and flow cytometric analysis revealed monocytic leukemia. This is the second report of generalized eruptive histiocytosis associated with acute monocytic leukemia. We discuss the differential diagnoses of the clinical picture and stress that this benign cutaneous disorder may indicate an underlying hematologic malignancy.
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PMID:Atypical generalized eruptive histiocytosis associated with acute monocytic leukemia. 1457 38

The diagnosis of pulmonary Langerhans cell histiocytosis might be refined by demonstrating reliability of a new cell marker, i.e., Langerin (CD207), used on bronchoalveolar lavage fluid. For this purpose, we collected material from patients with this disease and also with sarcoidosis and idiopathic pulmonary fibrosis as controls. In addition to the immunocytochemical detection of Langerin, we examined the expression profiles of CD1a and the macrophage tandem-repeat mannose receptor (CD206). To test accessibility of Langerin, a C-type lectin, for mannosides, we employed reverse lectin histochemistry using mannose-containing neoglycoproteins. The analysis revealed a significantly increased percentage of CD1a- and Langerin-positive cells in pulmonary Langerhans cell histiocytosis in comparison with both other studied diseases. No expression of the 175-kDa mannose-binding lectin (CD206) in Langerhans cells was observed. Evidently, binding sites on the cells were not accessible for the mannose-containing neoglycoligand. These results provide evidence for the usefulness of Langerin-directed immuno- and glycohistochemical monitoring of bronchoalveolar lavage fluid in the diagnosis of pulmonary Langerhans cell histiocytosis.
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PMID:Diagnostic relevance of Langerin detection in cells from bronchoalveolar lavage of patients with pulmonary Langerhans cell histiocytosis, sarcoidosis and idiopathic pulmonary fibrosis. 1472 67

The liver can be involved directly, by infiltration, and indirectly--by remote effects--in the histiocytoses of childhood. Langerhans cell disease, the most well recognized of these, infiltrates the liver directly but has a remarkable selectivity for the bile ducts. Early involvement is by Langerhans cell histiocytosis (LCH) infiltration leading to a sclerosing cholangitis and, eventually, biliary cirrhosis. Gamma glutamyl transpeptidase is a sensitive indicator of liver infiltration in a child with LCH. The indirect effects on the liver of LCH elsewhere in the body are mediated through an accompanying macrophage activation syndrome that is most likely responsible for hepatomegaly and hypoalbuminemia but without direct infiltration. These indirect effects are completely reversible. Juvenile xanthogranuloma/xanthoma disseminatum, a related dendritic cell disorder that can have systemic manifestations, has a strikingly different pattern, with a predominantly portal infiltrate spilling over into the adjacent lobule but sparing the biliary tree. The biology of the liver lesions is not clear but regression has been documented. Myeloproliferative disorders and myeloid leukemias can express CD1a and/or S100 protein, mimicking LCH but distinguished by their sinusoidal pattern. The primary macrophage histiocytoses such as the familial hemophagocytic syndromes can lead to severe liver damage. Although a portal lymphohistiocytic infiltrate is most characteristic, it is probably cytokine-mediated hepatocellular damage that can cause substantial functional impairment or even hepatic failure as a presenting feature. Liver involvement in other, more unusual histiocytic disorders, is also illustrated.
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PMID:Liver involvement in the histiocytic disorders of childhood. 1502 67

Langerhans cell histiocytosis (LCH) is a pleomorphic disease entity characterized by local or disseminated atypical Langerhans cells found most commonly in bone, lungs, mucocutaneous structures, and endocrine organs. Cutaneous disease occurs in approximately one quarter of all cases. Cutaneous findings include soft-tissue swelling, eczematous changes, a seborrheic dermatitis-like appearance, and ulceration. We report a rare case of LCH confined to the scalp with folliculocentric infiltrates. This 32-year-old male patient presented with follicularly based erythema, scale, and pustules unresponsive to topicals and oral antibiotics. The patient's lesions mimicked lichen planopilaris and folliculitis decalvans during the disease process. On hematoxylin and eosin stain, scalp biopsy showed a perivascular interstitial patchy lichenoid mononuclear cell infiltrate that focally abutted follicular infundibula. Prominent mononuclear cells having reniform nuclei were present, and immunoperoxidase stains for CD1a confirmed Langerhans cell differentiation. Serological and imaging workup failed to display systemic involvement.
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PMID:Adult onset folliculocentric langerhans cell histiocytosis confined to the scalp. 1502 94

Congenital self-healing reticulohistiocytosis (CSRH), a rare benign variant of Langerhans cell histiocytosis (LCH), is characterized by (a). congenital skin lesions, (b). a healthy infant with no systemic involvement, (c). the histopathologic finding of a Langerhans cell infiltrate and (d). spontaneous involution within the first year of life without sequelae. We report a Taiwanese girl born with widespread hemangioma-like lesions. The diagnosis of LCH was confirmed by finding a diffuse dermal infiltrate of S-100-protein- and OKT6 (CD1a)-positive mononuclear cells and the presence of Birbeck granules in 10% of the mononuclear cells ultrastructurally. The diagnosis of CSRH was further established by rapid and complete involution of the lesions in 3 months. No recurrence was noted for 7 years. Our case illustrates that CSRH can mimic diffuse neonatal hemangiomatosis clinically; thus, it is important to include CSRH in the differential diagnosis of congenital or neonatal hemangiomatosis.
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PMID:Congenital self-healing reticulohistiocytosis mimicking diffuse neonatal hemangiomatosis. 1505 4

Monoamine storage in secretory granules is mediated by the vesicular monoamine transporters 1 and 2 (VMAT1 and VMAT2). The aim of our study was to identify monoamine-handling normal and neoplastic inflammatory cells in the skin by their expression of VMAT1 and VMAT2. Normal skin from various parts of the body, as well as 21 cases of cutaneous mastocytosis and 10 cases of cutaneous Langerhans cell histiocytosis were analyzed by immunohistochemistry, radioactive in situ hybridization, and double-fluorescence confocal microscopy. VMAT2-positive cells in the subepidermal layer were identified as mast cells by their expression of tryptase. Neoplastic mast cells in all cases of cutaneous mastocytosis retained their VMAT2 positivity. The intraepidermal VMAT2-expressing cells were identified as Langerhans cells by their CD1a positivity. VMAT2 was absent from Langerhans cell histiocytosis. VMAT2 is an excellent marker for normal and neoplastic mast cells. The expression of VMAT2 demonstrates the capacity of mast cells for monoamine storage and handling. The presence of VMAT2 in epidermal Langerhans cells revealed a previously unrecognized monoamine-handling phenotype of these cells and indicates possible involvement of amine storage and release associated with antigen presentation. Absence of VMAT2 in neoplastic Langerhans cells indicates a loss of monoamine handling capacity of these cells during tumorigenesis.
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PMID:The vesicular monoamine transporter 2 (VMAT2) is expressed by normal and tumor cutaneous mast cells and Langerhans cells of the skin but is absent from Langerhans cell histiocytosis. 1515 Feb 86

While tumors of dendritic cell lineage may have overlapping histomorphologic features, most but not all cases can be classified using an immunohistochemical panel, including CD21, CD23, CD35, CD1a, and S-100. Based on observations that clusterin is expressed in benign follicular dendritic cells, clusterin expression in 32 dendritic cell tumors was evaluated. Diffuse strong staining for clusterin was seen in 12 of 12 follicular dendritic cell tumors. Two of these cases were negative for traditional markers (CD21, CD23, CD35); they were classified based on characteristic ultrastructural features. Three of 6 interdigitating dendritic cell tumors were negative for clusterin and 3 showed focal weak positivity. Clusterin staining in Langerhans cell histiocytosis ranged from negative (6 of 14) to weak/moderate (8 of 14). Follicular dendritic cell tumors behaved as benign tumors or low-grade sarcomas. Interdigitating dendritic cell tumors demonstrated a widely variable behavior, ranging from benign to rapidly fatal disease. Based on this initial study, strong clusterin staining supports a diagnosis of follicular dendritic cell tumor. Thus, staining for clusterin is useful in classification of dendritic cell tumors, particularly when the more common markers of follicular dendritic cells are not expressed.
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PMID:Clusterin expression distinguishes follicular dendritic cell tumors from other dendritic cell neoplasms: report of a novel follicular dendritic cell marker and clinicopathologic data on 12 additional follicular dendritic cell tumors and 6 additional interdigitating dendritic cell tumors. 1525 4


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