[Transudative myelomatous pleurisy revealing pleural localization of primary plasma cell leukemia]. / Pleurésie myélomateuse transudative révélant une localisation pleurale d'une leucémie à plasmocytes de novo.

Primary plasma cell leukemia (PPCL) is an aggressive and rare variant of multiple myeloma (MM), with frequent extramedullary involvement, mainly liver and splenic lesions. Pleuropulmonary involvement has rarely been described in the literature. We report a case of primary plasma cell leukemia in a 46-year-old patient, whose first symptom was pleural effusion with mediastinal adenopathies simulating a pleural localization of a lymphomatous process. However, blood smear examination, electrophoresis as well as immunofixation of plasma proteins and immuno-histochemistry have helped to guide the diagnosis. Pleurisy is a rare mode of revelation of plasma cell leukemia and is a factor of poor prognosis.