Plasma Cell Disorders

These plasma cell neoplasms are responsible for the 15% of the deaths caused by lymphoid neoplasms. The most common and also the most fatal of these neoplasms is multiple myeloma. This presents as tumor masses scattered throughout the skeletal system. Solitary myeloma, also known as plasmacytoma, is an infrequent variant that presents as a single mass in bone or soft tissue. The other uncommon variant is called smoldering myeloma defined by a lack of symptoms. Waldenstrom macroglobulinemia causes hyper viscosity of blood due to elevated levels of immunoglobulin M.

It is usually associated with lympho plasmocytic lymphoma which occurs usually in adults. Heavy chain disease is a rare monoclonal gammopathy and is usually seen in association with a diverse a group of disorders which includes lympho plasmocytic lymphoma and an unusual small bowel marginal zone lymphoma that occurs in malnourished populations (so called Mediterranean lymphoma). The common sign is the synthesis and secretion of heavy-chain fragments. Primary or immunocyte-associated amyloidosis results from a monoclonal proliferation of plasma cells secreting light chains that are deposited as amyloid. Monoclonal gammopathy of undetermined significance (MGUS) is applied to patients without signs or symptoms who have small to moderately large M components in their blood. MGUS is very common in older adults and may transform to multiple myeloma or other symptomatic plasma cell neoplasms.