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

Disseminated dermal tumors in a 71-year-old male represented the first clinical manifestation of a chronic myelomonocytic leukemia. The dermal infiltrate in one of the nodules consisted predominantly of closely packed pleomorphic Langerhans' cells (LC) with typical Birbeck granules and a strong reactivity for S-100 protein. The simultaneous presence of immature myeloid cells led to the suspicion of an underlying myeloproliferative disorder. The diagnosis of chronic myelomonocytic leukemia was subsequently confirmed by bone marrow histology and blood picture. Although some peritrabecular foci of histiocytic cells were detected in bone marrow, no LC could be identified by electron microscopy and histochemical methods. Tumorous aggregates of LC in myeloproliferative disorders have not been described in the literature. Histiocytosis X and related diseases could be definitely excluded in the present case. This case obviously suggests an interrelation between the myeloproliferative disease and the focal accumulation of LC in the dermis. In animal studies by Katz et al. LC have been shown to originate in the bone marrow, whereas the origin of LC in man is still a matter of discussion. The present case supports the hypothesis that LC in man are also of myeloid origin. The neoplastic blood monocytes could be the precursors of the dermal LC. This differentiation did not take place in the bone marrow but only in the dermis where LC occur under nonneoplastic conditions ("homing").
 ...
PMID:Dermal Langerhans' cell tumor in chronic myelomonocytic leukemia. 316 10

The term histiocyte refers to cells of either the macrophage or Langerhans cell lineages. The histiocytic disorders are characterized by the proliferation of cells of these lineages. With recent advances in knowledge of the developmental biology of histiocytic cells, it is now possible to formulate a reasonable catalogue of histiocytic diseases based on ultra-structural and phenotypic markers of cellular origins and molecular or chromosomal markers of malignancy. The catalogue includes the following groups of diseases. Nonmalignant reactive macrophage disorders include (1) macrophage storage diseases, (2) several benign proliferative macrophage disorders that predominantly involve skin and bone, and (3) several hemophagocytic syndromes that vary from indolent and benign to fulminant and fatal. In some of the latter disorders, viruses have been identified as the inciting stimulus. The malignant macrophage disorders include (1) acute monocytic leukemia and (2) chronic myelomonocytic leukemia. A rare disorder that gave rise to a permanent cell line with an anomaly of chromosomal segment 5q35 may also be an example of a histiocytic malignancy. The existence of a separate category of true histiocytic lymphoma of macrophage type is uncertain. Reactive Langerhans cell disorders include (1) congenital self-healing histiocytosis, (2) the many variants of eosinophilic granuloma, and (3) a related disorder designated as relapsing Langerhans cell histiocytosis that is characterized by a relapsing course and infiltration of bone and soft tissues by Langerhans cells. Presumptively neoplastic diseases of Langerhans and dendritic cells include (1) progressive Langerhans cell histiocytosis, a disease with prominent involvement of blood and BM as well as skin and viscera; (2) Langerhans cell lymphoma, and (3) dendritic cell lymphoma. However, clonality as a marker of malignancy has not been proven in these disorders.
 ...
PMID:Histiocytes and histiocytosis. 771 2

We have prospectively evaluated the feasibility and results of the biotin-avidin immunoadsorption method (Ceprate SC system) for a phase I/II study of T-cell depletion of granulocyte colony-stimulating factor (G-CSF) mobilized peripheral blood progenitor cells (PBPC) for allogeneic transplantation. Twenty consecutive patients, median age, 40 years (21 to 54) and diagnoses of chronic myeloid leukemia in chronic phase (n = 5), acute myeloblastic leukemia (n = 7), acute lymphoblastic leukemia (n = 2), chronic myelomonocytic leukemia (n = 1), refractory anemia with excess of blasts in transformation (n = 3), histiocytosis X (n = 1), and chronic lymphocytic leukemia (n = 1), were conditioned with cyclophosphamide (120 mg/kg) and total body irradiation (13 Gy; 4 fractions). HLA identical sibling donors received G-CSF at 10 microg/kg/d subcutaneously (SC); on days 5 and 6 (19 cases) and days 5 to 8 (1 case) donors underwent 10 L leukapheresis. PBPC were purified by positive selection of CD34+ cells using immunoadsorption biotin-avidin method (Ceprate SC) and were infused in the patients as the sole source of progenitor cells. No growth factors were administered posttransplant. The median recovery of CD34+ cells after the procedure was of 65%. The median number of CD34+ cells infused in the patients was 2.9 (range, 1.5 to 8.6) x 10(6)/kg. The median number of CD3+ cells administered was 0.42 x 10(6)/kg (range, 0.1 to 2). All patients engrafted. Neutrophil counts >500 and >1,000/microL were achieved at a median of 14 days (range, 10 to 18) and 15 days (range, 11 to 27), respectively. Likewise, platelet counts >20,000 and >50,000/microL were observed at a median of 10 days (range, 6 to 23) and 17 days (range, 12 to 130), respectively. Graft-versus-host disease (GVHD) prophylaxis consisted of cyclosporine plus methylprednisolone. No patient developed either grade II to IV acute or extensive chronic GVHD. After a median follow-up of 7.5 months (range, 2 to 22) three patients have relapsed, and one of them is again in hematologic and cytogenetic remission after infusion of the donor lymphocytes. Two patients died in remission: one on day +109 of pulmonary aspergillosis and the other on day +251 of metastasic relapse of a previous breast cancer. Sixteen of the 20 patients are alive in remission after a median follow-up of 7.5 months (range, 2 to 22). In conclusion, despite the small number of patients and limited follow-up, it appears that this method allows a high CD34+ cell recovery from G-CSF mobilized PBPC and is associated with rapid engraftment without significant GVHD, and with low transplant related mortality.
 ...
PMID:Rapid engraftment without significant graft-versus-host disease after allogeneic transplantation of CD34+ selected cells from peripheral blood. 916 34

Langerhans cell histiocytosis (LCH) and malignancy occurring in the same individual is unusual and has generally been the subject of isolated case reports. LCH is a rare condition in adults. Its cause is uncertain but, with the recent demonstration of clonality and its association with malignant disease, there has been a renewal of interest. We report a singular case of Letterer-Siwe disease associated with a chronic myelomonocytic leukemia developing in an elderly woman. The simultaneous occurrence of both malignant disorders supports the hypothesis of a common genetic origin.
 ...
PMID:Letterer-Siwe disease associated with chronic myelomyonocytic leukemia: a fortuitous association? 2037 75

Langerhans cell histiocytosis (LCH) is a rare histiocytic neoplasm characterized by clonal proliferation of Langerhans cells in multi-organ systems including skin, bone, pituitary gland, liver and spleen. Skin-limited involvement of LCH usually indicates an indolent clinical course; however, in rare cases, LCH is accompanied by other myeloproliferative disorders, which may determine the prognosis. An 82-year old Japanese man presented with numerous asymptomatic facial papules clinically simulating rhinophyma. Although findings of histopathology and general examination including bone marrow biopsy led to the diagnosis of cutaneous LCH, he died from chronic myelomonocytic leukemia, which emerged 10 months after the initial diagnosis of LCH. The previously reported cases of LCH concomitant with other hematological disorders are also summarized and described compared with the present case.
 ...
PMID:Cutaneous Langerhans cell histiocytosis in elderly with chronic myelomonocytic leukemia. 2462 74

Erdheim-Chester disease (ECD) is a rare non-Langerhans cell histiocytosis that most commonly affects adults and is driven by a high frequency of mutations in BRAF, MAP2K1, and kinases promoting MAPK signaling. Because of the relative rarity of ECD, key clinical features of the disease may not be well defined. Across a multi-institutional cohort of 189 patients with ECD and ECD overlapping with Langerhans cell histiocytosis (so-called mixed histiocytosis [MH]), we identified an unexpected and heretofore undescribed frequent occurrence of myeloid neoplasms among patients with ECD and MH. Some 10.1% (19/189) of patients with ECD have an overlapping myeloid neoplasm, most commonly occurring as a myeloproliferative neoplasm (MPN), myelodysplastic syndrome (MDS), or mixed MDS/MPN overlap syndrome (including chronic myelomonocytic leukemia). Consistent with this, molecular analysis frequently detected hallmark driver mutations of myeloid neoplasms (such as JAK2V617F and CALR mutations) coexisting with those characteristic of histiocytosis (such as BRAFV600E and MAP2K1 mutations). Histiocytosis patients diagnosed with a concomitant myeloid malignancy were significantly older at diagnosis and more commonly presented with MH than those without a myeloid malignancy. In some cases, the presence of distinct kinase mutations in the histiocytosis and myeloid neoplasm resulted in discordant and adverse responses to kinase-directed targeted therapies. These data highlight the clinical importance of evaluating adults with histiocytosis for a concomitant myeloid neoplasm.
 ...
PMID:High prevalence of myeloid neoplasms in adults with non-Langerhans cell histiocytosis. 2867 34

Distinguishing classical dendritic cells from other myeloid cell types is complicated by the shared expression of cell surface markers. ZBTB46 is a zinc finger and BTB domain-containing transcription factor, which is expressed by dendritic cells and committed dendritic cell precursors, but not by plasmacytoid dendritic cells, monocytes, macrophages, or other immune cell populations. In this study, we demonstrate that expression of ZBTB46 identifies human dendritic cell neoplasms. We examined ZBTB46 expression in a range of benign and malignant histiocytic disorders and found that ZBTB46 is able to clearly define the dendritic cell identity of many previously unclassified histiocytic disease subtypes. In particular, all examined cases of Langerhans cell histiocytosis and histiocytic sarcoma expressed ZBTB46, while all cases of blastic plasmacytoid dendritic cell neoplasm, chronic myelomonocytic leukemia, juvenile xanthogranuloma, Rosai-Dorfman disease, and Erdheim-Chester disease failed to demonstrate expression of ZBTB46. Moreover, ZBTB46 expression clarified the identity of diagnostically challenging neoplasms, such as cases of indeterminate cell histiocytosis, classifying a fraction of these entities as dendritic cell malignancies. These findings clarify the lineage origins of human histiocytic disorders and distinguish dendritic cell disorders from all other myeloid neoplasms.
 ...
PMID:Expression of the transcription factor ZBTB46 distinguishes human histiocytic disorders of classical dendritic cell origin. 2974 54