PULMONARY INVOLVEMENT IN LYMPHOMA

Intrathoracic involvement is common in both Hodgkin's disease (HD) and non-Hodgkin's lymphoma (NHL). The most common manifestation is medias tinal lymphadenopathy. In HD, nodal involvement is by contiguity and u sually involves the superior mediastinum, while the findings in NHL ar e more variable. Pulmonary parenchymal disease occurs in 38% of HD and 24% of NHL. In untreated HD, parenchymal involvement is invariably as sociated with mediastinal lymphadenopathy and often with widespread di sease. Three distinct radiological patterns of pulmonary lymphoma are recognised: nodular, bronchovascular-lymphangitic and pneumonic-alveol ar. Rarely lymphoma may be endobronchial. Pleural effusion occurs in 1 6% of lymphoma patients and is usually associated with disease elsewhe re. It is frequently caused by lymphatic obstruction but may be due to direct pleural involvement by tumour. Chylothorax may occur in NHL bu t is unusual in HD. Diagnosis of intrathoracic lymphoma is by transbro nchial or transthoracic biopsy or by needle aspiration of tissue or pl eural fluid. The addition of immunostaining improves the diagnostic yi eld in equivocal cases. Treatment and prognosis vary depending on cell -type, location and extent of disease.