Primary pulmonary histiocytosis X in two patients with Hodgkin's disease.

The lungs may be involved in patients with histiocytosis X as part of the generalised disease, but histiocytosis X confined to the lungs without extrapulmonary involvement is rare. This report describes two cases of primary pulmonary histiocytosis arising in patients with Hodgkin's disease. It is impossible to state with certainty whether the pulmonary histiocytosis arose as a response to the defects of cell-mediated immunity, or as a consequence of immunosuppression by radiation and chemotherapy.