Browsing by Subject "Mastocytosis"

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    Mastocytosis in children: Clinicopathological study based on 35 cases
    (Murcia : F. Hernández, 2007) Kiszewski, A.E.; Alvarez-Mendoza, A.; Ríos-Barrera, V.A.; Hernández-Pando, R.; Ruiz-Maldonado, R.
    Immunohistochemical staining is useful in the diagnosis of bone marrow infiltration in systemic mastocytosis. However, it is not clear if antibody staining may be helpful in the diagnosis of cutaneous mastocytosis (CM). We studied the histological appearance of CM in 35 pediatric patients. Cases were assigned to three basic clinical groups: I - Urticaria pigmentosa (UP, n=29); II - Mastocytomas (n=4); and III - Diffuse Cutaneous Mastocytosis (DCM, n=2). The analysis of clinical information revealed an association between the presence of diarrhea and a higher number of cells/field. Nine doubtful cases, all of them macules, were selected based on the scarcity of mast cells (MC) and the absence or rarity of other inflammatory cells. We compared the number of cells identified in Giemsa and immunohistochemical stains in definite and doubtful cases. The intraclass correlation statistic tested the concordance between each staining method. All 9 dubious cases according to the Giemsa stain had their CM diagnosis confirmed by the immunohistochemistry analysis. The intraclass correlation between Giemsa and c-kit was good (0.7) when the number of MC was high. However, there was no correlation between the mast cells counts in the two different stains in the dubious cases. The immunohistochemistry with c-kit might make CM diagnosis easier, especially in the macular cases, when there is a lower number of MC.
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    Systemic mast cell disease (mastocytosis). General aspects and histopathological diagnosis
    (Murcia : F. Hernández, 1997) Horny, H.P.; Ruck, P.; Krober, S.; Kaiserling, E.
    Systemic mast cell disease/mastocytosis (SMCD) is best defined as a multitopic proliferation of cytologically andlor functionally abnormal tissue mast cells (TMC). SMCD preferentially involves the bone marrow, skin, spleen, liver, and lymph nodes. The histopathological diagnosis of SMCD may be very difficult to make, and the disease is often not considered in the differential diagnosis of lymphoreticular neoplasia. In suspected cases of SMCD, basic dyes such as Giemsa and toluidine blue are useful to demonstrate the specific metachromatic granules of TMC. The naphthol AS-D chloroacetate esterase reaction has also proved to be very reliable for enzyme-histochemical identification of TMC. Major diagnostic problems may arise in cases of malignant or «aggressive» SMCD exhibiting tissue infiltrates consisting predominantly of highly atypical, non-metachromatic TMC, which are usually also only weakly reactive for chloroacetate esterase. Immunostaining with antibodies against the mast cell-specific proteases tryptase and chymase has proved to be of great value for establishing the correct diagnosis in such cases. Anti-tryptase antibodies have major diagnostic significance due to their extremely high sensitivity and specificity. The classification of SMCD is controversial, but there is increasing support for the differentiation of at least two major subtypes that differ in prognosis: (i) a benign or «indolent» variant in which skin involvement (urticaria pigmentosa-like skin lesions) is usual, but associated malignant hematological disorders are rare; and (ii) a malignant or «aggressive» variant where skin involvement is usually absent but concomitant malignant hematological disorders (myelodysplastic and myeloproliferative syndromes and acute non-lymphocytic leukemias) are very common. Preliminary molecular biological studies of a few cases of malignant SMCD using the recently developed HUMARA assay have yielded evidence that the disease is monoclonal.