Lymphoproliferative Diseases Involving the Lung

Nomenclature and classification schemes of lymphoproliferative disorders have undergone changes over the past 20 years. Malignant lesions are now best classified according to the current World Health Organization (WHO) schemes.1,2 In the lung and pleura, primary lymphoproliferative disorders represent a wide and overlapping spectrum of conditions from reactive polymorphous and polyclonal processes to various entities of malignant lymphomas. The natural history of these diverse conditions is variable, and further heterogeneity is recognized within distinct disease entities. Primary pleuropulmonary lymphoproliferative diseases are rare, whereas lymphomas secondarily affecting the lungs occur in up to 20% of autopsy cases. Although most diagnoses are based on light microscopy, immunohistochemical and molecular investigations have assumed a vital role. A schematic classification of lymphoid disorders involving primarily the lung and pleura is shown in Table 119-1.