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

Sinus histiocytosis with massive lymphadenopathy (SHML), or Rosai-Dorfman disease, is rare histiocytic disorder of known origin which shares several cell markers with Langerhans' cell histiocytosis (LCH). Although Rosai-Dorfman cells exhibit an aberrant immunophenotype, the indolent clinical course of SHML suggests a reactive disorder rather than a neoplastic process. Until recently this was prevailing opinion concerning LCH also, but recent studies have detected clonal histiocytes in all forms of this latter condition, which is therefore considered a clonal neoplastic disorder with highly variable biological behaviour. To determine whether the histiocytic proliferation in SHML is polyclonal or clonal we used X-linked polymorphic loci to assess clonality in lesional tissues in two women. Polymorphic regions of the human androgen receptor (HUMARA) locus were amplified by polymerase chain reaction (PCR) analysis. The HUMARA locus was informative in both cases and, following digestion with methylation-sensitive enzymes, typical polyclonal X-inactivation patterns were observed. Since abnormal cells accounted for > 90% lesional tissue cells, we conclude that Rosai-Dorfman histiocytic proliferation was polyclonal in the women studied.
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PMID:Evidence for a polyclonal nature of the cell infiltrate in sinus histiocytosis with massive lymphadenopathy (Rosai-Dorfman disease). 854 85

Chester-Erdheim disease is a rare non-langerhans cell histiocytosis characterized by a xanthomatous infiltration of foamy macrophages. The cause and pathogenesis remain unclear. The aim of the present study was to determine whether Chester-Erdheim disease is a polyclonal reactive disease or a clonal neoplastic disorder. The clonal status of samples obtained from five patients with Chester-Erdheim disease was studied. DNA was extracted from fixed and paraffin-embedded sections after microdissection and clonal status was studied using the Xchromosome inactivation pattern of the human androgen receptor gene (HUMARA assay). One patient was homozygous for the HUMARA gene and noninformative. Three other cases were monoclonal. One was polyclonal, and this case showed a dense reactive infiltrate in association with spumous macrophages. This study suggests strongly that Chester-Erdheim disease is a monoclonal lesion consistent with neoplastic disorder. Thus, Chester-Erdheim disease may be considered as the "macrophage" counterpart of Langerhan's cell histiocytosis in the histiocytosis spectrum. Further studies are needed to establish the origin of this clonal proliferation.
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PMID:Chester-Erdheim disease: a neoplastic disorder. 1049 45

Pulmonary Langerhans' cell histiocytosis (LCH) is a form of Langerhans' cell disease that primarily affects smokers in the third to fifth decade. Extrapulmonary manifestations are rare. Its clinical course is typically characterized by stabilization or regression of bilateral micronodular infiltrates seen on chest radiographs; progression to honeycomb fibrosis is rare. Because the clinical course of pulmonary LCH is distinct from systemic multiorgan LCH, currently thought to be a clonal proliferative disorder, we examined the X-linked polymorphic human androgen receptor assay (HUMARA) locus to assess clonality in female patients with one or more discrete LCH cell nodules in open lung biopsies. Langerhans' cells (LCH cells) were excised from formalin-fixed, paraffin-embedded tissue by microdissection to assure a relatively pure cellular population, and studies for differential methylation patterns at the HUMARA locus were performed. Twenty-four nodules in 13 patients were evaluated. Seven (29%) were clonal and 17 (71%) were nonclonal. Of six cases with multiple discrete nodules, three (50%) showed a nonclonal LCH cell population. In one biopsy with five nodules, two nodules were clonal with one allele inactivated, one nodule was clonal with the other allele inactivated, and two nodules were nonclonal. In contrast to systemic LCH, pulmonary LCH appears to be primarily a reactive process in which nonlethal, nonmalignant clonal evolution of LCH cells may arise in the setting of nonclonal LCH cell hyperplasia. Cigarette smoking may be the stimulus for pulmonary LCH in contrast to other forms of LCH.
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PMID:Pulmonary Langerhans' cell histiocytosis: molecular analysis of clonality. 1134 75

Some immunologic diseases are characterized by profound loss or primary dysfunction of a given population of cells. The atypical cellular disorders discussed here all bear some similarities in that abnormal proliferations of lymphocytes and macrophages or dendritic cells result in lymphadenopathy, skin rashes, bone lesions and infiltrations of nearly any other organ system. What are the similarities and the differences between Langerhans cell histiocytosis (LCH), sinus histiocytosis with massive lymphadenopathy (SHML) or Rosai-Dorfman disease, and Castleman's disease (CD)? Studies on LCH have some advantages since it was described before the others, and organized clinical trials have been done since the 1980s. The understanding of SHML benefited from a registry maintained by Drs. Rosai and Dorfman. CD was described fifty years ago and for one subtype has the most clearly defined etiology (HHV-8 infection) of the three atypical cellular disorders discussed here. In Section I, Dr. Kenneth McClain examines the unanswered question of whether LCH is a malignant clonal disorder or an inflammatory response triggered by aberrant cytokine expression or a virus. Advocates of the malignant proliferation theory rest their case primarily on the following two points: Clonality of the CD1a+ Langerhans cells was demonstrated by analysis of the human androgen receptor in patients with single bone lesions (Low Risk) or multisystem disease including spleen, liver, bone marrow, or lung (High Risk). Although no consistent chromosomal abnormalities have been reported, loss of heterozygosity (LOH) has been defined by comparative genomic hybridization. Those in the "inflammatory response" camp note that non-clonal proliferation of Langerhans cells in adult pulmonary LCH also have LOH by the same method. The pathologic cells have not been successfully grown in culture or immune-deficient mice and don't have a "malignant" morphology. While the basic scientific arguments continue, important advances in the treatment of LCH have been made by international collaborations of the Histiocyte Society. Risk groups have been clearly defined and the response to therapy after the initial 6 weeks is known to be the strongest prognostic variable for outcome. In Section II, Dr. Yasodha Natkunam reviews the features of SHML, which most often presents as painless cervical lymphadenopathy, although many patients can have extranodal involvement as well. These sites include the skin, respiratory tract, bone, lung, gastrointestinal tract, and brain. The diagnosis rests on finding intact lymphocytes in the cytoplasm of activated macrophages as well as accumulation of mature plasma cells. Hemolytic or non-hemolytic anemias, hypergammaglobulinemia, and elevated erythrocyte sedimentatin rate (ESR) are often found with SHML. An intriguing finding of human herpesvirus (HHV)-6 viral proteins in SHML has been reported in several patients, but needs further study. SHML associated with lymphoproliferations triggered by defects in apoptosis are discussed since this mechanism may provide a clue to the etiology. Therapy for SHML varies greatly in reported case series. Many patients have spontaneous regression or resolution after surgical removal of isolated node groups. Others with systemic involvement may benefit from chemotherapy, but no clinical trials have been done. In Section III, Dr. Steven Swerdlow clarifies key features of the four types of CD. Localized cases are divided into the hyaline vascular type and plasma cell type. Both are usually cured by surgical excision and have symptoms mainly of a mass lesion, although the latter often also has constitutional symptoms. The two types are distinguished largely by the nature of the follicles and the number of interfollicular plasma cells. Interleukin (IL)-6 expression is increased in the plasma cell type. Multicentric CD of the plasmablastic type is most often found in HIV-positive patients with coincident HHV-8 infection. Many have lymphomas or Kaposi sarcomas. Other cases of multicentric CD are also most like the plasma cell type, however, with disseminated disease and constitutional symptoms. A wide variety of anti-neoplastic drugs, radiation therapy, anti-IL-6 and rituximab or atlizumab have been used with varying success in patients with multicentric CD. Clinical trials are needed for SHML and CD and registration of adult and pediatric patients on current LCH trials are encouraged.
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PMID:Atypical cellular disorders. 1556 88

Langerhans cell histiocytosis (LCH) has been described in association with a variety of neoplasms preceding, after, or synchronous with the other tumor. In some cases, a neoplasm may arise as a complication of therapy for LCH, and in others, the association may be coincidental. Synchronous occurrence has been reported most commonly in association with malignant lymphoma in which discrete proliferations of Langerhans cells (LCs) histologically indistinguishable from LCH are seen. In most cases, these LCs are closely related to or intermingling with the primary pathology. The nature of LCs in this context remains elusive with debate as to whether they represent a true clonal neoplasm or an exaggerated reactive phenomenon. The lack of evidence for LCH progression or disease elsewhere strongly supports the latter. We have encountered 5 examples of LCH-like proliferations occurring in the context of other lymphoproliferative disorders. These include 2 cases of mycosis fungoides and 1 of cutaneous B-cell pseudolymphoma, associations that to our knowledge have not been described before. Two patients were female, and the clonality of the LC proliferation was assessed using laser capture microdissection and the human androgen receptor. The results showed that the LCs forming discrete nodules in a case of cutaneous B-cell pseudolymphoma and a case of Hodgkin's lymphoma were polyclonal. This suggests that, at least in a proportion of cases, the aggregates of LCs occasionally identified within other lymphoproliferative lesions represent a reactive proliferation rather than a potentially aggressive second neoplasm.
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PMID:Lesions resembling Langerhans cell histiocytosis in association with other lymphoproliferative disorders: a reactive or neoplastic phenomenon? 1750 98

Erdheim-Chester disease (ECD) is a rare non-Langerhans form of histiocytosis characterized by xanthomatous tissue infiltration with foamy histiocytes. It is still controversial whether these histiocytic proliferations represent monoclonal neoplastic populations or are part of a polyclonal reactive process. This is a case report of ECD in a 76-year-old Chinese woman. We investigated the clinicopathological features and clonality of the histiocytes using laser microdissection and a clonality assay based on X-chromosomal inactivation mosaicism in female somatic tissues, as well as on the polymorphism of phosphoglycerate kinase (PGK) and androgen receptor (AR). According to our results, the lesion was composed of lipid-laden histiocytes and focal fibrous tissues. The lipid-laden histiocytes were positive for CD68 and CD163, but negative for CD1a and S-100. Electron-microscopic examination showed no Birbeck granules, but the presence of lipid vacuoles. Moreover, the result of the clonality assay demonstrated that these cells formed a polyclonal population. In conclusion, ECD is a rare non-Langerhans' cell histiocytosis. Its nature may be a non-neoplastic lesion; however, additional studies with larger sample sizes are necessary to conclusively prove our hypothesis.
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PMID:Clonal status and clinicopathological feature of Erdheim-Chester disease. 1933 22

Some studies have demonstrated that Langerhans cell histiocytosis (LCH) is a neoplastic hyperplasia of Langerhans cells, however some researchers consider that clonality should be assessed in more patients with LCH, both at disease presentation and during the disease course. Monoclonality is a major characteristic of most tumours, whereas normal tissue and reactive hyperplasia are polyclonal. To elucidate the nature of Langerhans cells further, the present study investigated the clinicopathological features and clonality of three cases of LCH in female patients using laser microdissection and a clonality assay, based on X-chromosomal inactivation mosaicism in somatic tissues and polymorphism of the androgen receptor gene. The results indicated that LCH was composed of Langerhans cells with a characteristic morphological appearance, eosinophils, giant cells, neutrophils and foamy cells. Immunohistochemically, the Langerhans cells were positive for CD1a, S-100 protein and vimentin. The clonality assay demonstrated that the Langerhans cells formed a monoclonal population, showing that LCH is neoplastic. We conclude that LCH is characterized by clonal proliferation, although additional studies with larger sample sizes are required to prove this conclusively.
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PMID:Clonal status and clinicopathological features of Langerhans cell histiocytosis. 2081 48