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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 clonal/neoplastic nature of
Langerhans cell histiocytosis
(
LCH
) has recently been demonstrated by a high prevalence of BRAF mutations, including pulmonary
LCH
(PLCH). We hypothesized that BRAF-induced senescence, as demonstrated in nevi and melanoma, is involved in the pathogenesis of
LCH
and PLCH. In a series of pulmonary (19 cases) and non-pulmonary
LCH
(19 cases), including five aggressive cases, we investigated occurrence of the BRAF V600E mutation by molecular analysis and/or immunohistochemistry using a validated antibody (VE1). The expression of cell-senescence markers p16(INK4a) and p21(CIP1/WAF1) was also immunohistochemically investigated. We demonstrated that 6/19 cases of
LCH
and 12/19 cases of PLCH were VE1 positive, matching with molecular analysis, and in all cases both p16(INK4a) and p21(CIP1/WAF1) were expressed, irrespective of BRAF mutation status. Interestingly, all the aggressive cases did not express p16(INK4a), thus suggesting that loss of senescence control could be related to clinical
aggressiveness
of
LCH
, as in melanoma.
...
PMID:Oncogene-induced senescence distinguishes indolent from aggressive forms of pulmonary and non-pulmonary Langerhans cell histiocytosis. 2447 9
Langerhans cells are antigen presenting dendritic cells and tumours arising from these are rare. The tumours arising from these dendritic cells are divided into two categories according to a WHO classification:
Langerhans cell histiocytosis
and Langerhans cell sarcoma. It is the degree of atypia and clinical
aggressiveness
that distinguishes the two subtypes. Langerhans cell sarcoma (LCS) is a neoplastic proliferation of Langerhans cells which can occur in skin, bone marrow, lymph nodes, spleen, liver, and lung. LCS can present with multiple cutaneous and systemic lesions. We present a case of Langerhans cell sarcoma with a unique morphological appearance and variable immunohistochemical profile within a single cutaneous lesion. LCS is a rare malignancy and its diagnosis is based on morphology, immunophenotypical examination, and ultrastructural analysis by electron microscopy. Our case highlights a unique morphological description of LCS wherein the pleomorphic neoplastic cells show epidermotropism and are surrounded by a variable amount of inflammatory infiltrate within a single cutaneous lesion. A single cutaneous lesion of Langerhans cell sarcoma with variable immunohistochemical profile has not been described so far.
...
PMID:Langerhans Cell Sarcoma: A Case Report Demonstrating Morphological and Immunophenotypical Variability within a Single Lesion. 2862 93
