1/8. Immunohistochemical properties of bone marrow mast cells in systemic mastocytosis: evidence for expression of CD2, CD117/Kit, and bcl-x(L).In an attempt to identify novel diagnostic markers for mast cell (MC)-proliferative disorders, serial bone marrow (bm) sections of 22 patients with mastocytosis (systemic indolent mastocytosis, n = 19; mast cell leukemia [MCL], n = 1; isolated bm mastocytosis, n = 2) were analyzed by immunohistochemistry using antibodies against CD2, CD15, CD29, CD30, CD31, CD34, CD45, CD51, CD56, CD68R, CD117, HLA-DR, bcl-2, bcl-x(L), myeloperoxidase (MPO), and tryptase. Staining results revealed expression of bcl-x(L), CD68R, and tryptase in neoplastic MCs (focal dense infiltrates) in all patients. mastocytosis infiltrates were also immunoreactive for CD45, CD117 (Kit), and HLA-DR. In most cases, the CD2 antibody produced reactivity with bm MCs in mastocytosis, whereas in control cases (reactive bm, immunocytoma, myelodysplastic syndrome), MCs were consistently CD2 negative. Expression of bcl-2 was detectable in a subset of MCs in the patient with MCL, whereas no reactivity was seen in patients with SIM or bm mastocytosis. mastocytosis infiltrates did not react with antibodies against CD15, CD30, CD31, CD34, or MPO. In summary, our data confirm the diagnostic value of staining for tryptase, Kit, and CD68R in mastocytosis. Apart from these, CD2 may be a novel useful marker because MCs in mastocytosis frequently express this antigen, whereas MCs in other pathologic conditions are CD2 negative.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
2/8. "Occult" mastocytosis with activating c-kit point mutation evolving into systemic mastocytosis associated with plasma cell myeloma and secondary amyloidosis.A case of a 70-year-old man presenting with exsudative enteropathy due to light-chain-associated amyloidosis is reported. The diagnosis of systemic mastocytosis associated with IgG/lambda plasma cell myeloma and secondary generalised amyloidosis was carried out by morphological evaluation of bone marrow biopsy. The c-kit point mutation D816Y was detected by molecular analysis. Two years before, a cystadenolymphoma of the left parotid gland had been removed. A moderate increase of loosely scattered spindle-shaped mast cells, a subpopulation of them expressing CD25, an antigen that is not expressed by normal or reactive mast cells, was shown by retrospective analysis carried out on an intraparotideal lymph node. The c-kit mutation D816Y was shown by the molecular analysis of the lymph node. In summary, the notion that systemic mastocytosis may very rarely be associated with B cell neoplasms and that neoplastic mast cell infiltrates may be obscured because of only a minimal increase of atypical mast cells, which are outnumbered by other non-neoplastic cells in the same tissue, is supported by this case. This finding was preliminarily termed "occult" mastocytosis.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
3/8. Different patterns of spleen involvement in systemic and malignant mastocytosis. A histological and immunohistochemical study of three cases.Three cases of splenic involvement in three different types of generalized mastocytosis (systemic mast cell disease) are reported. The macroscopic, histological and ultrastructural modifications of the spleen are described. Each case exhibited a different morphological pattern. Giemsa staining, fluorescence after acridine orange staining and naphthol ASD chloracetate esterase reaction are shown to be valuable for diagnosis. By comparison, immunohistochemistry seemed not to be very useful, because no specific antigens are expressed. These findings are compared to previously published cases. Their value for the diagnosis and the prognosis are discussed.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
4/8. Solitary mastocytoma of the eyelid. A case report with special reference to the immunocytology of human tissue mast cells, and a review of the literature.Solitary mastocytoma (mast cell naevus) of the skin represents a relatively rare dermal tumour. Its occurrence on the lower eyelid is exceptional. We report the case of a 4 month old male infant who exhibited a firm, yellowish nodule (1 cm in maximum diameter) on the lower lid of the right eye from birth. Histologically, the tumour consisted of strongly metachromatic tissue mast cells (TMC) infiltrating the whole dermis, the adjacent subcutaneous tissue and the lid muscle. Since comparable skin lesions in other sites were not observed, a diagnosis of solitary mastocytoma was made. Immunocytological investigations revealed strong reactivity of the TMC to antisera against vimentin, common leucocyte antigen (CLA), alpha 1-antitrypsin (alpha 1-AT) and alpha 1-antichymotrypsin (alpha 1-ACT). A minor proportion of the TMC reacted to antisera against lysozyme and KiB3. Surprisingly, the TMC also reacted to antisera against certain regulatory peptides (RP), namely adrenocorticotropic hormone (ACTH), peptide histidine isoleucine (PHI), leu-enkephalin and met-enkephalin. However, absorption controls revealed that the immunostaining for ACTH and the two enkephalins was non-specific. The immunocytological phenotype of TMC suggests a close relationship to the myeloid-monocytic lineage, but a possible relationship between TMC and the diffuse neuroendocrine system needs further investigation.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
5/8. Kit ligand/mast cell growth factor-independent differentiation of mast cells in myelodysplasia and chronic myeloid leukemic blast crisis.Autonomous, factor-independent growth and differentiation of malignant cells in preleukemic and leukemic disease states is a well-recognized phenomenon and is often associated with a poor prognosis. mast cells are distinct hematopoietic cells and express a unique profile of antigens. growth and differentiation of normal mast cells is dependent on mast cell growth factor (MGF), the ligand of the c-kit protooncogene product. In this study, we screened for mast cell-lineage involvement in 52 patients suffering from myeloid leukemias, myelodysplastic syndromes (MDS), systemic mastocytosis, or other diseases by probing for mast cell-related molecules (c-kit, tryptase, histamine, and MGF) and by analyzing kit ligand/MGF-independent growth of mast cells in long-term suspension culture. Of the 52 patients tested, 2 patients with refractory anemia with excess of blast cells in transformation and 1 patient suffering from chronic myeloid leukemia blast crisis (CML-BC) were diagnosed as mastocytic disease. These patients were characterized by complex chromosomal abnormalities, splenomegaly, high percentages of circulating metachromatic cells (5% to 25%), high levels of cellular tryptase (> 10 ng/10(5) peripheral blood mononuclear cells/mL) and a tryptase/histamine (ng:ng) ratio greater than 1. The metachromatic cells expressed the mast-cell-related surface antigen c-kit, but not basophil-related antigens (CD11b, CDw17). Furthermore, in these 3 patients, spontaneous, MGF-independent growth of mast cells along with spontaneous synthesis of tryptase was demonstrable in long-term culture. No autocrine production, paracrine production, or overproduction of MGF was found. The spontaneous growth of mast cells could neither be abbrogated by addition of monoclonal antibodies (MoAbs) to c-kit nor by MoAbs against MGF (< 5% inhibition), whereas factor (MGF)-dependent differentiation of mast cells in these patients could be abbrogated by MoAbs to c-kit or MoAbs to MGF (> 70% inhibition, P < .001). In addition, serum MGF levels in these patients were within the normal range and MGF could not be detected in cell-free culture supernatants. All 3 patients showed rapid progression of disease and had a survival time of less than 1 year. In conclusion, we describe a unique form of transformation in MDS and CML-BC characterized by mast cell lineage involvement and factor-independent differentiation of mast cells. This form of leukemic transformation has to be delineated from chronic myeloid leukemia with basophilia or basophil crisis, from primary mast cell leukemia, and from monocytic leukemias and myelodysplastic disorders associated with basophilia.- - - - - - - - - - ranking = 3keywords = antigen (Clic here for more details about this article) |
6/8. Solitary fibromastocytic tumor arising in an inguinal lymph node: the first description of a unique spindle cell tumor simulating mastocytosis.A 77-yr-old man presented with a right inguinal mass. At herniotomy, an enlarged inguinal lymph node was also removed. Gross examination revealed a firm gray tumorous nodule measuring 3 cm in maximum diameter. On histological examination, the lymphatic tissue was found to have been almost completely replaced by spindle-shaped tumor cells arranged in whorls and bundles. In Giemsa-stained sections, about one-third of the tumor cells were seen to be strongly metachromatic tissue mast cells. The other tumor cells reacted only with a monoclonal antibody against vimentin out of a broad panel of antibodies directed against various antigens expressed by leukocytes, mesenchymal cells, and epithelial cells. A small fraction of the nonmetachromatic tumor cells reacted with the proliferation-associated antibody MIB1. Immunostaining with an antibody against p53 tumor-suppressor gene products was negative. Electron-microscopic examination revealed mast cells containing abundant granules, which were intermingled with fibroblasts that had bizarre, elongated nuclei. No myofibroblasts, desmosomes, or basement membrane material were detected. Clinical examination revealed no abnormalities, and blood and bone marrow findings were completely normal. A diagnosis of solitary (apparently benign) fibromastocytic tumor was established on the basis of the relative tumor cell numbers, the cytological features, and the clinical data. To the authors' knowledge, this is the first description of a solitary spindle cell tumor arising in a lymph node and simulating mastocytosis.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
7/8. bone marrow mastocytosis associated with an undifferentiated extramedullary tumor of hemopoietic origin.The case of a 62-year-old man who presented with acute abdominal pain and a widespread tumor involving the retroperitoneum is described. Three weeks after initial presentation, the patient died suddenly of acute cardiac failure with signs of arrhythmia. autopsy revealed a disseminated tumor with infiltration of the retroperitoneal fat, as well as nodules in the left testis and the right atrium. The tumor cells were reactive for CD45, vimentin, and chloroacetate esterase, but were unreactive with a broad spectrum of antibodies against myelomonocytic and lymphocytic antigens and with antibodies against tryptase and c-kit (CD117), which are characteristic markers for mast cells. However, the bone marrow exhibited the typical picture of mastocytosis, with disseminated clusters of differentiated spindle-shaped cells that stained strongly for tryptase, c-kit, and chloroacetate esterase. No infiltrates of well-differentiated mastocytosis could be detected in any of the extramedullary tissues investigated. A diagnosis of bone marrow mastocytosis with an associated undifferentiated extramedullary tumor of hemopoietic origin was established. By definition, the extramedullary tumor could not be diagnosed as a granulocytic sarcoma or (differentiated) mastocytoma, but the possibility that a mast cell progenitor could be involved in the evolution of both tumors cannot be ruled out.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
8/8. Sequential immunophenotypic analysis of mast cells in a case of systemic mast cell disease evolving to a mast cell leukemia.The immunophenotypic characteristics of both bone marrow (BM) and peripheral blood (PB) mast cells (MC), from a patient suffering from an aggressive systemic mast cell disease (SMCD), were sequentially analyzed by flow cytometry using direct immunofluorescence. Analysis was carried out at diagnosis, during clinical response induced by interferon alfa-2h/prednisone therapy, and later at relapse. Our results show that together with the CD117 and IgE characteristic markers, at diagnosis BM MC showed strong expression of CD11c, CD13, CD29, CD33, CD44, CD45, CD63, and CD71, and they were also positive for CD2, CD22, CD25, and CD54 although at a lower level. PB MC displayed similar immunophenotypic characteristics although they had a lower expression of CD11c, CD25, CD33, CD63, CD69, and CD71 with a higher reactivity for CD117. Unlike BM MC, PB MC were weakly positive for CD41a and CD61. Sequential studies showed decreased numbers of both BM and PB MC during clinical response associated with a higher expression of the CD29 and CD54 adhesion molecules. In turn, clinical relapse was related to increased numbers of PB and BM MC together with lower CD2, CD11c, CD45, and and CD54 expression and a higher reactivity for the CD117 and CD25 antigens. CD2 had become negative at the last follow-up study. In addition, an increased proportion of S-phase MC was observed at relapse. These findings suggest that the assessment of the quantitative expression of cell-adhesion molecules and growth-factor receptors together with cell cycle studies of mast cells could be of value for monitoring therapy and predicting clinical outcome in aggressive SMCD.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |