Plasmacytoma of the breast

Extramedullary plasmacytomas are unusual tumors that generally represent the initial manifestation of systemic multiple myeloma. I studied a plasmacytoma of the breast in a patient who has remained free of symptoms nine years after initial diagnosis.     

Plasmacytoma of the thyroid

Three cases of plasmacytoma of the thyroid are described and their clinical and histological features recorded. Two were considered to be true extramedullary plasmacytomas, the third the initial manifestation of a disseminated myelomatous process. Plasmacytomas of the thyroid are shown to have many features in common with malignant lymphomas in this site, including an association with Hashimoto thyroiditis in more than half the reported cases. No certain method of assessing the prognosis in any individual case has yet been described.     

Hepatocellular Hyperplasia, Plasmacytoma Formation, and Extramedullary Hematopoiesis in Interleukin (IL)-6/Soluble IL-6 Receptor Double-Transgenic Mice

Cytokines interact not only with membrane anchored receptors, but also with specific soluble receptors which circulate in the bloodstream. In general, soluble cytokine receptors such as soluble tumor necrosis factor receptor, soluble interleukin 1 receptor, and soluble interleukin 4 receptor compete with their membrane-bound counterparts for the ligands and therefore act as antagonists. In contrast, soluble receptors for cytokines of the interleukin-6 (IL-6) family complex with their ligands act agonistically. Interestingly, the complex of IL-6 and the soluble interleukin 6 receptor (sIL-6R) activates target cells that do not express the membrane-bound IL-6R and therefore cannot respond to IL-6. To identify cellular responses that are due to IL-6/sIL-6R but not to IL-6 alone, IL-6/sIL-6R double-transgenic mice were generated and compared with IL-6 single-transgenic mice. IL-6/sIL-6R transgenic mice develop a severe phenotype showing 1) marked hepatocellular hyperplasia frequently surrounded by peliosis and necrosis, 2) significant acceleration and aggravation of plasmacytoma formation, and 3) excessive activation of extramedullary hematopoiesis in spleen and liver followed by a subsequent increase of all cellular components in the peripheral blood. These in vivo data suggest that the sIL-6R recruits primarily unresponsive cell populations such as hematopoietic progenitor cells and hepatocytes to IL-6-induced proliferation, but also enhances the known mitogenic effect of IL-6 on plasma cells and thereby contributes to plasmacytoma formation.     

Surface Immunoglobulins of Circulating Lymphocytes in Mouse Plasmacytoma III. The Effect of Plasmacytoma RNA on the Immune Response

RNA extracted from several plasmacytomas of BALB/c mice was previously shown in in vitro and in vivo experiments to induce the synthesis of receptors on B cells with The immunochemical characteristics of the respective plasmacytoma globulin. These findings were also produced with immuno-globulin-free RNA extracted from the plasma of plasmacytoma animals. The results of the present study indicate that the injection of 0.5-1 mg of RNA into CF₁ mice also has an inhibiting effect on the primary response to sheep erythrocytes (SRBC) as measured by agglutinin titers and plaque forming cells. On the other hand, RNA injected prior to the second injection of SRBC did not inhibit the secondary response. RNA from normal tissue and RNase-inactivated RNA were ineffective. These findings suggest that an RNA fraction of the plasmacytoma participates in the mediation of the characteristic impairment of the primary immune response in myeloma.     

Extramedullary hematopoiesis in pyogenic granuloma

Extramedullary hematopoiesis (EMH) suggests the presence of hematopoietic stem cells (HSC) outside bone marrow. EMH has been reported, albeit rarely, in pyogenic granuloma (PG), a polypoid lobular capillary hemangioma. However, statistical data have hitherto been lacking on the actual incidence of EMH in PG. Therefore, we here reviewed 157 consecutive cases using routine diagnostic surgical slides and found unequivocal EMH in 17 (10.8%). This indicates that EMH is a rather common finding in PG, which could thus have strong potential to be an important resource for the study of HSC.     

Extramedullary plasmacytoma of the breast.

The clinical and histopathological features of a case of solitary extramedullary plasmacytoma of the breast are described. After 46 mth of follow-up, there has been no recurrence of the tumour, and no evidence of further extramedullary plasmacytomas, multiple myeloma or diffuse myelomatosis either clinically, radiologically or on biochemical and haematological investigations. She has developed diabetes mellitus. Distinction is made between the true extramedullary plasmacytoma and those which are a manifestation of multiple myeloma. The unpredictable behaviour and prognosis of extramedullary plasmacytomas is indicated.     

Plasmacytoma of the clivus: a case report

A 60-year-old male presented with headache and diplopia for 2 months. Computed tomography of the head showed a heterogeneously enhancing expansile lytic lesion in clival region. The patient underwent surgery and histopathological examination revealed it to be plasmacytoma of the clivus. The multiple myeloma work-up was negative. Solitary plasmacytoma localized to the skull base is extremely rare. Prior to this, only three case reports of plasmacytoma of the clivus have been described in the English literature.