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)

The coincidence of T-cell acute lymphoblastic leukemia (T-ALL) and histiocytic disorders, including hemophagocytic lymphohistiocytosis (T-ALL/HLH) and Langerhans cell histiocytosis (T-ALL/LCH), is very seldom and is usually associated with a dismal prognosis. Retrospective statistical analysis of all T-ALL patients, who have been registered in the BFM-ALL trials from 1981 - 2001 and who have subsequently developed a LCH/HLH, in order to identify any common risk factors pre-disposing to the synchronous occurrence of both disorders. Six out of 971 T-ALL patients had either HLH or LCH ( approximately 0.03% of treated T-ALL/year). The mean age at diagnosis of T-ALL/HLH/LCH was significantly lower than in the remaining T-ALL group (4.05 +/- 0.59 vs 8.82 +/- 0.14 years; p = 0.000). The mean initial leukocyte count was higher than in the non-HLH/LCH group (270,700 +/- 60,677 microl(-1) vs 134,141 +/- 5,663 microl(-1); p = 0.074). No hemophagocytosis was seen in the initial bone marrow (BM) smears. Five of 6 patients obtained a good prednisone response (GPR) at day 8 in peripheral blood with <5% blasts at day 15 in BM and all cases were in complete remission (CR) at day 33. The mean time until development of the histiocytosis was 17.95 months (range 2.5 - 33 months). Four patients developed a HLH and 2 a LCH. All patients with HLH showed a multi-organ involvement, while the LCH patients had only local disease. Only the LCH patients survived, while all patients with HLH died. The authors recommend a close follow-up for at least 3 years after diagnosis in younger T-ALL patients with high initial leukocyte count.
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PMID:Histiocytosis following T-acute lymphoblastic leukemia: a BFM study. 1626 75

Langerhans cell histiocytosis (LCH) and related entities are neoplasms of unknown pathogenesis. Here, we describe studies assessing the role of NOTCH1 mutations in LCH, which were based on a case of fatal Langerhans cell tumor after T-cell acute lymphoblastic leukemia (T-ALL). Although the two types of neoplasm in this patient were temporally and pathologically distinct, molecular analyses showed that they harbored the same T-cell receptor gene rearrangements and two activating NOTCH1 mutations involving exons 27 and 34. The exon 27 mutation altered a conserved cysteine residue in the N-terminal portion of the NOTCH1 heterodimerization domain, while the mutation in exon 34 introduced a premature stop codon that results in the deletion of C-terminal negative regulatory PEST domain. Analysis of cDNA prepared from the aggressive Langerhans cell tumor showed that the NOTCH1 mutations were aligned in cis, a configuration that caused synergistic increases in NOTCH1 signal strength in reporter gene assays. Immunohistochemistry confirmed that the Langerhans cell tumor also expressed NOTCH1 protein. Although these data suggested that NOTCH1 mutations might contribute to the pathogenesis of typical sporadic LCH and related neoplasms occurring in the absence of T-ALL, an analysis of 24 cases of LCH and Rosai-Dorfman Disease occurring in patients without an antecedent history of T-ALL revealed no mutations. Thus, activating NOTCH1 mutations appear to be unique to aggressive Langerhans cell tumors occurring after T-ALL. Persistent expression of NOTCH1 in such tumors suggests that Notch pathway inhibitors could have a role in the treatment of these unusual neoplasms.
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PMID:Aggressive Langerhans cell histiocytosis following T-ALL: clonally related neoplasms with persistent expression of constitutively active NOTCH1. 1787 53

The association of multiorgan histiocytosis after acute lymphoblastic leukemias is very rare as most cases are localized forms of Langerhans cell histiocytosis (LCH). We report on an 18-year-old man diagnosed with B-cell acute lymphoblastic leukemia (B-ALL) with p16 deletion (9p21). He was treated with induction chemotherapy using the Spanish PETHEMA group protocol and achieved complete remission. Three months after the diagnosis of B-ALL, he developed a severe multiorgan histiocytosis that is clinically suggestive of LCH but lacked typical immunohistochemical features of LCH and indeterminate cell histiocytosis: CD1a was strongly positive, CD68 and S-100 protein were moderately positive, and langerin was negative. The drugs of the first-line treatment recommended for LCH had been part of the chemotherapy of B-ALL that the patient had received. Therefore, we prescribed the second-line treatment for LCH (cytarabine and 2'-chlorodeoxyadenosine), and he achieved partial remission. The patient died during the aplasia induced by the third cycle of chemotherapy from pneumonia. We could not demonstrate the transdifferentiation of tumoral lymphocytes into histiocytes, using p16 deletion (9p21) as a marker, because these cells did not share the mutation. Neither could we study immunoglobulin-H rearrangement as we had exhausted all the tissue samples. In the medical literature, there are a few reported cases of T-cell acute lymphoblastic leukemia followed by disseminated LCH and just 1 case of B-ALL followed by localized LCH affecting the bones. Therefore, our patient may be the first published case of B-ALL followed by histiocytosis, which had 2 singularities: it was multiorgan and the immunohistochemistry was not typical of LCH.
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PMID:Multiorgan histiocytosis after B-cell acute lymphoblastic leukemia. 2128 61

A 4-year-old female child developed cutaneous Langerhans cell histiocytosis 6 months following a diagnosis of T-cell acute lymphoblastic leukemia. Imaging revealed no evidence of systemic disease. Seven months later, the first systemic lesion was discovered on laryngoscopy. Restaging Positron Emission Tomography - Computed Tomography at that time revealed new 18-fluorodeoxyglucose-positive lesions in the left apical pleural margin, right lower peri-esophageal region, left ventricular myocardium, pancreas, upper pole of the left kidney, and inguinal and gluteal regions consistent with progressive systemic disease. Genomic testing revealed a low tumor mutational burden as well as mutations in KRAS G12A, ARID1A Q524, CDKN2A/B loss, and an alteration in NOTCH1.
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PMID:Aggressive Langerhans cell histiocytosis following T-cell acute lymphoblastic leukemia. 3291 21