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Biomedical subjects

K Lennert

Publications and source records attributed to K Lennert.

At least 163 records · Page 9Linked to original sources
PubMed1979

[Non-Hodgkin malignant lymphomas of the digestive tract].

Study of the histology, epidemiology and course of 106 non-Hodgkins malignant lymphomas of the digestive tract seen in Tunisia revealed the high incidence of these ML in comparison with other malignant tumours of the same site and their predominance above all in young male subjects. The classification of these lymphomas has shown that forms with a high degree of malignancy are seen much more often than forms with a low degree of malignancy: Centroblastic ML accounted for more than 50 p. 100 of the histological forms seen in the intestine. Intermediate centroblastic and immunoblastic ML predominated in the stomach. Nodular ML is very rare. Finally, an important feature in the course of these tumours is worthy of note, i.e. the prolonged survival of 9 of our patients. This survival would however appear to be related more to the stage of the disease than to the histological type and the nature of the treatment used.

Adult↗
PubMed1978

Demonstration of immunoglobulin production by tumor cells in non-Hodgkin's and Hodgkin's malignant lymphomas and its significance for their classification.

Combined application of morphologic, immunochemical, and immunologic methods has led to a reinterpretation of non-Hodgkin's lymphomas and to the establishment of the Kiel classification. In the present paper, the main Ig-producing entities are considered. These are: 1. Chronic lymphocytic leukemia of the B-type (B-CLL)--a proliferation of lymphocytes and a few so-called prolymphocytes and lymphoblasts. The mean tissue IgM value is slightly increased; the serum IgM level is normal or reduced. The tumor cells bear SIg, and a majority of them have a receptor for C3d but always lack CIg and are usually devoid of receptors for C3b. 2. Lymphoplasmacytoid immunocytoma--a mixed proliferation of lymphocytes and centrocytes, blast cells, plasma cells, or plasmacytoid cells. The tissue Ig content is most often (91%) and most highly increased in this group, whereas the serum Ig level is increased in only 20% of the cases. The tissue IgM of 17 cases was shown to be monoclonal by IEF. Most tumor cells have SIg and a variable numbear CIg. The tumor cells bear both complement receptor subtypes, only a receptor for C3b, or no complement receptors at all. 3. Centroblastic/centrocytic lymphoma--usually a follicular proliferation of abundant small germinal center cells (centrocytes) and some large germinal center cells (centroblasts). The tumor cells bear SIg and both complement receptor subtypes. The C3b- and C3d-positive cells are located in the follicles, as in nonneoplastic lymphatic tissue. 4. Centrocytic lymphoma--a purebred, diffuse proliferation of the small germinal center cells (centrocytes). These cells bear SIg and receptors for C3b and C3d but usually lack CIg. 5. Centroblastic lymphoma--a proliferation of the large germinal center cells (centroblasts). 6. Lymphoblastic lymphoma of Burkitt's type. 7. Immunoblastic lymphoma--a diffuse proliferation of large basophillic cells resembling immunoblasts. The tissue IgM content is increased in 60% of the cases. It proved to be monoclonal with IEF in all five cases studied. The cells of five cases with increased tissue Ig content bore SIg. Nearly half of the cases studied showed CIg. Besides non-Hodgkin's lymphomas, paraffin sections of 87 biopsies from Hodgkin's disease were investigated for CIg in Hodgkin's and Sternberg-Reed cells. These cells stained positively in 68 cases, most often for IgG, followed by IgD. In five cases of the lymphocyte-depleted type, the staining of the Hodgkin's and Sternberg-Reed cells was restricted to one light chain type.

Burkitt Lymphoma↗
PubMed1978

Complement receptor subtypes C3b and C3d in lymphatic tissue and follicular lymphoma.

To substantiate the origin of follicular (nodular) lymphoma cells from germinal-centre cells, the lymphoma cells from 7 patients with follicular lymphoma and from 9 tonsils and 2 lymph nodes were studied for the presence and distribution of complement-receptor subtypes (i.e., the receptors for C3b and C3d). It was found that erythrocytes coated with antibodies and C3d (EAC3d) adhered exclusively to germinal centres, whereas erythrocytes coated with antibodies and C3b (EAC3b) adhered to germinal centres and in many instances to the regions between them. These findings indicate that germinal-centre cells bear both complement-receptor subtypes and that the B cells of the interfollicular area, which belong at least in part to the precursors of plasma cells, bear only a receptor for C3b. In frozen sections of follicular lymphomas, a similar distribution of complement-receptor subtypes was observed; EAC3d was bound exclusively to the neoplastic nodules, and EAC3b adhered to the neoplastic nodules and adjacent paranodular tissue. Receptor studies on suspended cells of both normal tonsils and follicular lymphomas revealed a slight predominance of EAC3d(+) cells or equal numbers of EAC3b(+) and EAC3d(+) cells. The complete congruence in the expression and distribution of complement-receptor subtypes between tissues from follicular lymphomas and those from normal and hyperplastic tonsils or lymph nodes suggests that follicular lymphoma represents the neoplastic counterpart of the reactive germinal centre.

Binding Sites↗
PubMed1978

Diagnosis and differential diagnosis of lymphoepithelial carcinoma in lymph nodes: histological, cytological and electron-microscopic findings.

(1) Lymphoepithelial carcinoma, which occurs in the nasopharynx and palatine tonsils, is a special variant of squamous-cell carcinoma with a non-neoplastic lymphocytic component. (2) The morphology of lymphoepithelial carcinoma is very characteristic if not specific. Therefore, whenever lymphoepithelial carcinoma is diagnosed in a cervical lymph node, the clinician must try to find the primary tumour in the nasopharynx or tonsils, by blind biopsy if necessary. (3) The 'inflammatory' component of lymphoepithelial carcinoma is often very conspicuous. Tuberculoid lesions, with or without caseation necrosis, and marked eosinophilia and plasmacytosis are highly characteristic and help to confirm the diagnosis. (4) The 'inflammatory' component, including the lymphocytes among and around the tumour cells, is not fully understood; but it would appear that T lymphocytes are responsible for all, or most, of the cellular reactions against the tumour.

Adolescent↗
PubMed1977

[Tissue mast cell count in immunocytoma and chronic lymphocytic leukaemia (author's transl)].

The amount and distribution of tissue mast cells in the three subtypes of immunocytoma (IC) were studied in lymph nodes of 58 cases and compared with the findings on 34 cases of chronic lymphocytic leukemia (CLL). There were significantly more mast cells in the lymphoplasmacytic and lymphoplasmacytoid subtypes of IC than in CLL. The median mast cell count for the polymorphic subtype of IC was also greater than that for CLL; however, this difference was not statistically significant. Tissue mast cells were diffusely distributed in the lymph nodes in IC, whereas they were chiefly located in the sinus in CLL. Moreover, the cells themselves and their granules were generally larger in IC. Increase in the number and altered distribution of the tissue mast cells in histological sections are therefore diagnostic aids for distinguishing IC from CLL.

Biopsy↗
PubMed1977

Immune histochemical and electron microscopic observations on so-called non-specific mesenterial lymphadenitis.

Two cases of so-called mesenterial lymphadenitis in childhood were investigated with the immunoperoxidase technique. One more case was studied electron microscopically. All three cases were morphologically identical. In two cases infection with Yersinia enterocolitica was proven serologically. The majority of the lymphoid cells which filled the strongly distended sinuses represented electron microscopically various steps of the lymphocyte transformation. Immune histochemically, the blasts contained large amounts of immunoglobulins. It is suggested that the mitogen and adjuvant activity of bacterial lipopolysaccharides may substantially be involved in the pathogenesis of the characteristic lesion of the mesenterial lymphadenitis.

B-Lymphocytes↗
PubMed1977

[Classiciation of non-Hodgkin's lymphomas of childhood (author's transl)].

The malignant non-Hodgkin's lymphomas of childhood are of highgrade malignancy only. There are lymphoblastic and immunoblastic forms. The lymphoblastic lymphomas can be of the Burkitt type (B-cell-derived) or of the "convoluted" or acid phosphatase type (T-cell-derived). A larger number of the lymphoblastic lymphomas are "unclassified" and usually do not belong to either the B-or the T-cell system (stem-cell-derived?). Most of the immunoblastic lymphomas (previously called "reticulosarcomas") are derived from the B-cell series. Besides the lymphomas in the actual sense, there are also true histiocytic reticulosarcomas of childhood. Hodgkin's disease is probably more common in childhood than all of the non-Hodgkin's lymphomas combined.

Acid Phosphatase↗
PubMed1976

Preliminary clinical findings on the Kiel classification of malignant lymphomas.

In 75 patients with non-Hodgkin Lymphomas the influence of the histopathological form, as judged by the Kiel classification, on the epidemiology and prognosis of the disease was examined retrospectively. The different forms of the Kiel classification influence in a typical way the age specific incidence rates and the prognosis of the disease.

Adolescent↗
PubMed1976

[Glomus cell clusters of the lymph node].

Nine lymph nodes with so-called benign nevus cell nevi were studied by light microscopy. In three cases the lymph nodes were also examined by electron microscopy. The solitary or multiple cell clusters were 35-645 mu in diameter and were usually found in the lymph node capsule or cortex. They were more frequent in the older patients. There was no predisposition for either sex. Specific morphologic features allowing clear cytologic identification of the cells were not evidient. In particular, there was no indication that they represented nevus cells. However, they showed a great morphologic similarity to glomus cells. In addition, they were usually found near blood vessels. We assume that the cell clusters were hamartias related to glomangiomas. We call them glomus cell clusters.

Adult↗