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Biomedical subjects

K Lennert

Publications and source records attributed to K Lennert.

At least 127 records · Page 7Linked to original sources

Histiocytic necrotizing lymphadenitis without granulocytic infiltration.

Twenty-seven cases of an unusual necrotizing lymphadenitis previously described only in Japan are reported as occurring in West Germany (23 cases), Iran (1 case), Italy (1 case), Korea (1 case) and Spain (1 case). The lesion frequently develops in the cervical lymph nodes of young women. It is characterized by infiltration of the cortex and/or paracortex by large collections of proliferating histiocytes and is devoid of granulocytes. Complete or, more often, incomplete necrosis of lymphoid tissue is seen in all cases. In cases with incomplete necrosis, the histiocytes are interspersed with pyknotic cells and nuclear debris. Based on the histological findings, the term "histiocytic necrotizing lymphadenitis without granulocytic infiltration" is proposed. Lesions to be considered in a differential diagnosis are malignant histiocytic neoplasms and necrotizing lymphadenitis with granulocytic infiltration, which is seen in lupus erythematosus and bacterial infections. The aetiology of histiocytic necrotizing lymphadenitis without granulocytic infiltration is still unclear. Some clinical and histological features indicate the possibility of an underlying viral infection.

Adult↗

Enzymecytochemical heterogeneity of human chronic T-lymphocytic leukemia as demonstrated by reactivity to dipeptidylaminopeptidase IV (DAP IV; EC 3.4.14.4).

The observation that the dipeptidylaminopeptidase IV (DAP IV; EC 3.4.14.4) occurs exclusively in T mu lymphocytes, stimulated the following study on cases of chronic lymphocytic leukemias. Thirty cases of human chronic lymphocytic leukemia were subjected to the DAP IV reaction in addition to the usually applied cytochemical and immunological tests (acid alpha-naphthyl acetate esterase, acid phosphatase, rosetting with sheep erythrocytes and surface Ig). DAP IV activity was measured directly in normal granulocytes, monocytes, B and T lymphocytes as well as in lymphocyte suspensions of leukemic cases. On a cytochemical level granulocytes, monocytes, B lymphocytes and all 24 cases of B-CLL were found to be DAP IV negative, though some of the latter showed positive reactions for AcE and AcP. From the six cases of T-CLL, five were positive to DAP IV cytochemically. No discrepancies were observed between cytochemical and biochemical results. It is concluded that DAP IV is a reliable and easy to perform marker for T mu lymphocytes and their neoplasias. The results have been interpreted as further evidence for a clonal nature of T-cell neoplasias.

Acid Phosphatase↗

Primary malignant lymphomas localized in salivary glands.

Biopsies from 25 patients with primary malignant lymphoma in the salivary region were investigated morphologically and the clinical findings were analysed. Cases showing myoepithelial sialadenitis or Sjögren's syndrome were not included. The tumour was localized in the parotid region in 21 cases and to the submandibular region in four cases. Non-Hodgkin's lymphoma was diagnosed on 21 biopsies and Hodgkin's disease on four: all patients were of stages I or II. The most frequent type of malignant lymphoma was the centroblastic-centrocytic type; sclerosis was found in all but one of these 15 cases. Polymorphic immunocytoma was diagnosed in two cases, centroblastic lymphoma in two cases and immunoblastic lymphoma in two cases. In eight patients, the lymphomas definitely originated in intraglandular lymph nodes; in 10 other patients, the lymphomas might have developed in intraglandular lymph nodes. It was not possible to determine the origin of the lymphoma in the other seven cases. The prognosis was relatively favourable.

Adult↗

S-100 protein in Langerhans cells, interdigitating reticulum cells and histiocytosis X cells.

S-100 protein was immunohistochemically demonstrated in the cells of cases of histiocytosis X such as eosinophilic granuloma, Hand-Schüller-Christian disease and Letterer-Siwe disease. Its presence was also shown in Langerhans cells of the epidermis and interdigitating reticulum cells in the lymph node, spleen and thymus. S-100 protein was not found in epithelioid cells in sarcoidosis, phagocytic macrophages, or dendritic reticulum cells in germinal centers. S-100 protein might be a new immunohistochemical marker for the Langerhans cells, interdigitating reticulum cells and histiocytosis X cells.

Histiocytosis, Langerhans-Cell↗

Morphologic findings in lymph nodes after occlusion of their efferent lymphatic vessels and veins.

Cervical lymph nodes of rabbits were congested for 24 hours, 7 days, and 14 days by occlusion of the nodal veins, efferent lymphatics, or both. The lymph nodes were examined by histologic and morphometric methods, and the results were compared with findings in control nodes. The present study demonstrated that the vascular sinus transformation (VST), observed first in human lymph nodes, is reproducible experimentally. Complete occlusion of both the veins and lymphatics led to a marked increase in volume of the nodes and often to total necrosis of their parenchyma. Incomplete occlusion of the veins combined with complete occlusion of the lymphatics or complete occlusion of the lymphatics alone resulted in VST as early as 7 days after the operation. In the first stage of VST, proliferation of the subendothelial tissue accompanied by proliferation of blood capillaries was noted. The proliferation started from the capsular side of the marginal sinus and from the trabecular side of the intermediate sinuses. Subsequently, the sinuses transformed into a framework of channels resembling blood capillaries. Without occlusion of the efferent lymphatics, VST did not develop. Complete or incomplete occlusion of the veins combined with complete occlusion of the lymphatics resulted in a pronounced thickening of the capsule, sclerosis of the medullary sinuses, depletion of lymphocytes in the nodal parenchyma, and cavernous dilation of the medullary sinuses. After occlusion of the lymphatics alone these changes were less extensive. Occlusion of veins alone caused only moderate thickening of the capsule and slight sclerosis of nodal parenchyma, but no VST. Total necrosis of the parenchyma occurred only after combined complete occlusion of nodal veins and lymphatics.

Animals↗

[History and clinical picture of lymphogranulomatosis X (including (angio)immunoblastic lymphadenopathy].

The term lymphogranulomatosis X (LgX) designates a clinicopathological entity of unknown etiology ("X"), which was first described by Forster and Moeschlin in 1954. LgX includes the "immunoblastic lymphadenopathy" of Lukes and to a large extent the "angioimmunoblastic lymphadenopathy" of Rappaport (except for the cases with active germinal centers), but in LgX there is another morphologic variant not mentioned either by Lukes or by Rappaport. To establish the morphologic diagnosis of LgX three typical changes of the affected lymph nodes are needed: effacement of the nodal architecture, absence of active germinal centers, and markedly increased proliferation of epithelioid venules. Cases with only partial effacement of nodal architecture, and especially with active germinal centers, were considered hyperimmune reactions (HR). This "hyperimmune reaction" may be an early stage of LgX: 4 of 39 cases showed later transformation into LgX. Based on cytologic aspects, five different variants of LgX are distinguished: immunoblastic predominance, plasma cell predominance, mixed cell type, epithelioid cell predominance and lymphocytic predominance. Case history and clinical picture of the five variants of LgX (172 patients) are reported and compared with HR (37 patients). In LgX the age peak is in the 7th decade; the youngest patient was 16 years old. HR are seen in children as well as in elderly people, the mean age being 49 years. In LgX males predominate and in HR females. In LgX the disorder is usually more generalized than in HR (80% versus 46% with generalized lymph node enlargement, 69% versus 24% with hepatomegaly and 62% versus 27% with splenomegaly). Skin involvement and high sedimentation rate are less frequent in HR. In LgX a Coombs-positive anemia is occasionally found; its origin is "aplastic" rather than hemolytic. Based on the data presented, some reflections relative to the etiology and pathogenesis of LgX are presented. Rubella virus should be considered a possible etiologic agent. In most cases with drug hypersensitivity, allergic reactions to drugs appear only in the course of the illness; in these cases drugs are ruled out as an etiologic factor. Occasionally, an augmented number of azurophil granulated lymphocytes (suppressor T-cells?) is observed in the blood, a fact that could be a pointer to the pathogenesis of LgX and possibly explain the high incidence of infections seen in this disorder.

Adolescent↗

Histopathological correlation of the Kiel with the original Rappaport classification of malignant non-hodgkin lymphomas.

Using the Kiel and the Rappaport classifications, a comparative histopathological analysis of 486 cases with non-Hodgkin lymphomas from a prospective study of the Kiel Lymphoma Study Group, still in progress, was performed. The greater part of Rappaport's classical lymphoma entities was found to be inhomogeneous and to include tumors of considerable prognostic heterogeneity, as shown by differences in actuarial survival. Some of the Kiel lymphoma entities have been identified in several lymphoma types of the Rappaport classification, indicating that "translation" of one scheme into the other is difficult or impossible. In addition, centrocytic lymphoma of the Kiel classification may not be homogeneous. On the whole, the Kiel classification appears to be superior to the original Rappaport classification in categorizing the various prognostically diverse types of non-Hodgkin lymphomas.

Germany, West↗

Cytogenetic findings in T-zone lymphoma.

Five cases of T-zone lymphoma were investigated with histologic, immunologic, and cytogenetic methods. The chromosome analyses were performed on lymphoma cells prepared immediately after removal of the lymph nodes. The chromosomes involved in structural rearrangements were nos. 1, 2, 3, 4, 14, and Y. Numbers 3, 5, 6, and 13 were lost by some tumors, and nos. 3 and 9 were gained. Chromosome 3 was involved most often in structural and numerical aberrations, whereas 14q + markers occurred in only one case. The importance of multidisciplinary studies is pointed out.

Aged↗

Mesenteric lymphadenitis due to Yersinia enterocolitica.

The histopathological diagnosis of Yersinia enterocolitica infections in mesenteric lymph nodes is described on the basis of biopsy material from 14 cases collected at the Lymph Node Registry in Kiel. In all cases, the aetiological diagnosis was verified by demonstrating significant antibody titres in serological tests and, in two cases, by isolating Yersinia enterocolitica from faeces. The mesenteric lymph nodes showed a rather specific histological picture. In all cases, the capsule was thickened by oedema and stained metachromatically. The cortical and paracortical pulp was always hyperplastic owing to an increase in the number of immunoblasts, plasmablasts, and plasma cells. The sinuses were dilated and filled with intensely basophilic cells that varied in size from small to large (plasmacytoid cells and precursors). Small, or relatively large accumulations of "immature histiocytes" (transformed lymphocytes) were seen in the sinuses in about two thirds of the cases. Occasionally, there were small foci of small histiocytes (emigrated monocytes) in the cortical pulp. An abscess similar to the abscesses found in abscess-forming reticulocytic lymphadenitis due to Yersinia pseudotuberculosis was evident in only one case. The differential diagnosis is also discussed. The diseases to be considered are mesenteric lymphadenitis due to Yersinia pseudotuberculosis or salmonella infection, and nonspecific mesenteric lymphadenitis.

Adolescent↗