[Primary pulmonary lymphoma].

Abstract

There are three distinct clinico-anatomical entities today covered by the definition of a primary clonal pulmonary lymphoid proliferation. These are pulmonary lymphomas of B cell phenotype, of low grade malignancy, B cell lymphomas of high grade malignancy and finally lymphomatoid granulomatosis whose clonal characteristic is sometimes difficult to confirm. This general review aims to specify the pathophysiological, diagnostic, prognostic and therapeutic aspects of these different types. Low grade B cell lymphoma is the most common pulmonary lymphoma. Their development depends on mucosa associated lymphoid tissue. They are most often indolent and present as a chronic alveolar opacity. Their prognosis is excellent and the modalities of treatment are discussed (no therapy, surgery or monochemotherapy). High grade B cell pulmonary lymphomas are much rarer and may result from the transformation of a low grade lymphoma or arise in a particular situation such as imunodepression. Their prognosis is poor and the therapeutic possibilities depend most often on the underlying disease. The presence of lymphomatoid granulomatosis in this group of pulmonary lymphomas is debatable. The demonstration of a clonal character of this proliferation is practically never obtained and there is often extra pulmonary disease. The prognosis of this type of illness is extremely variable because certain studies have shown a cure using corticosteroids and cyclophosphamide whilst others have found that the disease is always fatal in spite of using strong polychemotherapy.