[A case of chylothorax resulting from malignant lymphoma--pathogenesis of chylothorax: a new concept].

We report a case of chylothorax in a 51-year-old male with non-Hodgkin's lymphoma. Combination chemotherapy reduced the size of mediastinal lymph nodes dramatically, but retroperitoneal lymph nodes remained almost the same, and chylothorax subsequently developed. Lymphangiogram showed reticular spread of contrast material from the thoracic duct downwards but not above the diaphragm. These findings suggest that an obstruction of the infra-diaphragmatic but not the supra-diaphragmatic thoracic duct caused development of collateral lymphatic channels penetrating the diaphragm into the thoracic cavity, with subsequent formation of chylothorax.