Porth's Essentials of Pathophysiology, 4e

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presentation is unusual andmore common in elderlymen. Additional symptoms that suggest Hodgkin lymphoma include fevers, chills, night sweats, and weight loss. Pruritus and intermittent fevers associated with night sweats are classic symptoms of Hodgkin lymphoma. Other symptoms such as fatigue and anemia are indicative of disease spread. In the advanced stages of Hodgkin lymphoma, the liver, spleen, lungs, digestive tract, and, occasionally, CNS may be involved. As the disease progresses, the rapid proliferation of abnormal lymphocytes leads to an immunologic defect, particu- larly in cell-mediated responses, rendering the person more susceptible to viral, fungal, and protozoal infec- tions. Anergy, or the failure to develop a positive response to skin tests such as the tuberculin test, is com- mon early in the course of the disease. Diagnosis and Treatment. A definitive diagnosis of Hodgkin lymphoma requires that the Reed-Sternberg cell be present in a biopsy specimen of lymph node tissue. Computed tomography scans of the chest and abdomen commonly are used to assess for involvement of medi- astinal, abdominal, and pelvic lymph nodes. 44 If with initial screening the extent of lymph node involvement cannot be determined, PET imaging may be helpful. Persons with Hodgkin lymphoma are staged accord- ing to the number of lymph nodes involved, whether the lymph nodes are on one or both sides of the diaphragm, and whether there is disseminated disease involv- ing the bone marrow, liver, lung, or skin. The staging of Hodgkin lymphoma is of great clinical importance because the choice of treatment and the prognosis ulti- mately are related to the distribution of the disease. In addition, patients are designated stage A if they lack constitutional symptoms and stage B if 10% weight loss (over 6 months) or night sweats are present. Irradiation and chemotherapy are used in treating the disease. Most people with localized disease are treated with radiation therapy 46,47 whereas a combined approach using radiation and chemotherapy is used in persons with advanced disease. As the accuracy of staging techniques, delivery of radiation, and curative efficacy of combination chemotherapy regimens have improved, the survival rate of people with Hodgkin lymphoma also has improved. Plasma Cell Dyscrasias Plasma cell dyscrasias are characterized by expan- sion of a single clone of immunoglobulin-producing plasma cells and a resultant increase in serum levels of a single monoclonal immunoglobulin or its fragments. The plasma cell dyscrasias include multiple myeloma, lymphoplasmacytic lymphoma, and monoclonal gam- mopathy of undetermined significance. Monoclonal gammopathy of undetermined significance (MGUS) is characterized by the presence of the monoclonal immunoglobulin in the serum without other findings of multiple myeloma. Monoclonal gammopathy of undetermined significance is considered a premalignant condition. 4,7 Approximately 2% per year of persons

As with NHL, the cause of Hodgkin lymphoma is largely unknown. Although exposure to carcinogens and viruses as well as genetic and immune mechanisms have been proposed as causes, none has been proven to be involved in the pathogenesis of the disease. It appears that people with a history of infectious mononucleosis are at increased risk for the development of Hodgkin lymphoma. 4,7,45 Classification. The WHO classification proposed clas- sifying Hodgkin lymphoma into two major categories: nodular lymphocyte-predominant Hodgkin lymphoma and classic Hodgkin lymphoma. 4,45 Nodular lympho- cyte-predominant Hodgkin lymphoma represents only a small portion of all cases of HL and is a unique form that generally exhibits a nodular growth pattern, with or without diffuse areas and with rare Reed-Sternberg cells called “popcorn” or “L&H” (lymphohistiocytic) cells. It is often localized rather than disseminated at the time of diagnosis, exhibits a slowly progressive course, and has an overall survival rate greater than 80%. 4 Classic Hodgkin lymphoma is characterized by clonal proliferation of typical mononuclear Hodgkin cells and multinucleated Reed-Sternberg cells with invariable expression of CD30. Four variants of classic Hodgkin lymphoma have been described: nodular scle- rosing, mixed cellularity, lymphocyte rich, and lympho- cyte depleted. The nodular sclerosing type is the most common and is often found in adolescent and young adult women, 15 to 35 years of age. 4 Lymphocyte- rich Hodgkin lymphoma is a newly defined entity, and lymphocyte-depleted Hodgkin lymphoma is rarely diagnosed. At present, all subtypes of classic Hodgkin lymphoma are treated in the same manner. 46 Clinical Manifestations. Most persons with Hodgkin lymphoma present with painless enlargement of a single node or group of nodes. The initial lymph node involve- ment typically is above the level of the diaphragm (i.e., in the neck, supraclavicular area, or axilla). Mediastinal masses are frequent and are sometimes discovered on routine chest radiography. There may be complaints of chest discomfort with cough or dyspnea. Involvement of subdiaphragmatic lymph nodes at the time of FIGURE 11-9. Classic Reed-Sternberg cell; photograph shows normal lymphocyte compared with Reed-Sternberg cell. (From National Cancer Institute Visuals. No. CDR576466.)