[Polycystic endodermal heterotopy of the atrioventricular node]. / Heterotopía endodérmica poliquística del nódulo auriculoventricular.

We present the two first Spanish cases about the endodermic heterotopia of the atrioventricular node. This is an infrequent and probably congenital lesion, with a not well known histogenesis and associated with heart blocks and sudden death, which affects women in most cases. The first observation attaches a 55 years-old woman with an acute leukemia who died during the first chemotherapy treatment. The second observation affects a 25 years-old woman, with previous heart blocks, who died suddenly. A complete post-mortem study was done in both cases (including cardiac conduction system) with conventional histopathological study and extensive immunohistochemical panel. Ultrastructural study of first case was done. In both cases a multicystic and tubular lesion was found in the atrioventricular node region. It was lined by two or more cubic and polyhedral cell layers. In the cystic lumina an eosinophilic material, which corresponded to acid and neutral mucosubstances was found. The maximal lesion's diameter were: 0.9 and 1.3 cm, respectively. Immunohistochemically it was detected in both cases strong positivity for cytoqueratines, EMA, CEA and focally for chromogranin A and calcitonin. The immunohistochemical results in both cases express and endodermic differentiation (with neuroendocrine fenotipe).

[Systemic amyloidosis: clinico-pathologic study of 69 cases]. / Amiloidosis sistémicas: estudio clínico--patológico de 69 casos.

A series of 69 cases of systemic amyloidosis is discussed (12 primaries; 7 due to myeloma; 44 reactive; 5 due to familiar mediterranean fever and 1 portuguese familiar polyneuropathy) in which their clinical aspects, topographical distribution of the deposit and histochemical characteristics are studied using the potassium permanganate technique. According to sings and symptoms of presentation and topography there is a remarkable overlapping in the five types of amyloidosis. Only macroglossia was more frequent in primary amyloidosis (p less than 0.001). However the potassium permanganate technique can help in the classification. Considering the first clinical diagnosis. 83% of primary amyloidosis and 100% of amyloidosis due to myeloma, were resistant to permanganate. 84% of reactive amyloidosis and 100% of familiar mediterranean fever, were sensitive. The only case of portuguese familiar polyneuropathy showed resistance.

[The immunological characterization of 63 cases of Hodgkin's disease with a panel of 8 antibodies]. / Caracterización inmunológica de 63 casos de enfermedad de Hodgkin con un panel de ocho anticuerpos.

Sixty three cases of Hodgkin's disease are studied (two with lymphonodular predominance, 15 with diffuse lymphocyte predominance, 26 nodular sclerosis, 15 mixed cell and 5 lymphocyte depletion) with a panel of 8 monoclonal antibodies, material routinely used and included in paraffin: Ber H2 (CD30), Leu M1 (CD15), Common Leukocyte Antigen (CD45), L26 (CD20), MB2, UCHL1 (CD45 RO), MTI (CD43) and Epithelial Membrane Antigen. Ber H2 turned out to be the most usefull marker, positive in 100% of cases, independently of the histologic type. Positiveness with Leu M1 ranged from 100% (2/2 cases) of lymphonodular predominance, to 53.3% (8/15 cases) of diffuse lymphocyte predominance. The reactivity of the rest was variable, 1 though it is note worthy the positiveness of B markers (L26, MB2) in the two cases with lymphonodular predominance. In the other subtypes, reactivity with L26 was greater than that with MB2. T cell marker expression was minimal, except for the positiveness in 40% of cases (2/5) of the lymphocyte depletion type. In addition, the results of other series are revised and as a result the possible histogenesis of Hodgkin's disease is discussed.

[Adult T-cell lymphoblastic lymphoma associated with quiescent multiple myeloma]. / Linfoma linfoblástico T del adulto asociado a mieloma múltiple quiescente.

We report the case history of a female patient suffering of a T lymphoblastic lymphoma with an atypical presentation and evolution, consisting of pleuropericardiac effusion without mediastinic masses that coexists with a plasma cell dyscrasia that fulfils the criteria for stationary multiple myeloma. The possible pathogenic relationship between both processes is discussed, emphasizing the functional evolutive dissociation between the cellular constituents of both neoplasias, immature T lymphoblasts and plasma cells, respectively; this constitutes the first reported case in literature.