Malignant African lymphoma]

The article sets forth clinico-anatomical characteristics of Burkkit's lymphoma (50 observations). The investigation was carried out in the granted hospital in Kenya, were the authors had worked from 1967 to 1971. A histological feature of the tumour was a peculiar picture of the "starry sky", which was associated with the presence of large histiocytesmacrophages among prolypherating lymphoid cells, a cytological feature being the availability of vacuoles in the nucleus and cytoplasma. In the majority of cases Burkkit's tumour had multicentrical growth, most often localizations were jaws and ovaries. The authors observed in some cases considerable therapeutic effect of chemical preparations.     

Malignant lymphoma of the thyroid

Nine cases of malignant lymphoma of the thyroid are described; the clinical features and histological patterns are recorded and the latter related to results of serological tests for thyroid antibodies. The value of such tests in clinical assessment is discussed. The distribution of metastases and their predilection for the gastrointestinal tract is noted.     

Malignant lymphoma of the eye

A case of primary malignant lymphoma of the eye in a 78-year-old woman is reported. A centroblastic non-Hodgkin lymphoma showed prominent involvement of the retina with massive serous retinal detachment. A review of the literature is given.     

Malignant lymphoma in transplanted renal pelvis

A middle-aged man with chronic renal failure received a renal transplant from his healthy daughter. Two years later, malignant lymphoma developed in the transplanted renal pelvis. The lymphoma was found to be B-cell immunoblastic lymphoma bearing monoclonal IgG and kappa immunoglobulin, and it was of recipient origin.     

Malignant lymphoma of mucosa-associated lymphoid tissue

Lymphomas of the gastrointestinal tract, salivary glands, lung and thyroid are grouped together as tumours arising in mucosa-associated lymphoid tissue. The great majority of them are of B-cell origin but distinctive T-cell lymphomas are also recognized in the gastrointestinal tract. These lymphomas tend to remain localized for prolonged periods but, whereas the B-cell group respond favourably to local therapy, the T-cell group are associated with severe morbidity and their overall prognosis is extremely poor. Accepted histological classifications of non-Hodgkin's lymphomas are difficult to apply to these tumours. In this paper their morphological features are reviewed; recent findings based on immunohistochemistry and DNA analysis are presented; and the biological behaviour of these tumours is discussed insofar as they offer insight into mucosal immunological mechanisms.     

Malignant lymphoma in the gastrointestinal tract

The main function of gut-associated lymphoid tissue is to provide an adaptive protective mechanism to help defend the body from exogenous antigen. This complex function requires the coordination of various cellular elements, including B cells, T cells, macrophages, and the epithelial cells of the gut. The control of this remains poorly defined, but involves various cellular subpopulations, humoral factors acting by autocrine and paracrine means, and cell adhesion molecules regulating tissue tropisms. Disruption of these cybernetic mechanisms is likely to be fundamental to the development and behavior of gut lymphomas. Although conventional histopathology is likely to remain the mainstay of diagnosis and patient management, further advances in the understanding, diagnosis, and therapy of gut lymphomas will require a greater knowledge of the cells and molecules that regulate the lymphoid milieu of the gut.     

Malignant lymphoma simulating lymph node toxoplasmosis

On histological examination of 667 cases originally suspected of lymph node toxoplasmosis, 12 cases were diagnosed as malignant lymphoma and 15 cases as atypical hyperplasia (AH), suspicious of malignant lymphoma. All 12 malignant cases were of Hodgkin's disease: eight of the lymphocyte predominant nodular type, two of lymphocyte predominant diffuse type, and two of the nodular sclerosis type. In all cases, the lymph nodes contained small groups of epithelioid cells which were virtually indistinguishable from those seen in toxoplasmosis. In the differential diagnosis between lymph node toxoplasmosis and malignant lymphoma, the following features were found helpful. In toxoplasmosis the general structure is preserved and germinal centres are frequent, while in malignant lymphoma and in AH the general structure is destroyed. However, in some cases of toxoplasmosis germinal centres may be difficult to identify because their margins are indistinct due to clusters of epithelioid cells. Also, in some types of Hodgkin's disease and in some cases of AH with epithelioid cells, the general structure of the lymph node may be partially preserved. The occurrence of epithelioid cells within germinal centres seems to be a specific feature for toxoplasmosis; it was never seen in malignant lymphoma nor in AH. The occurrence of strands of monocytoid cells ( unreife Sinushistiocytose ) though a fairly typical feature of toxoplasmosis, was also occasionally seen in Hodgkin's disease or AH.