This is a case report of a 40-year-old man with leiomyosarcoma of the inferior vena cava. He had suffered from shortness of breath and edema on lower limbs over several months. Clinical examinations including UCG, CT and MRI revealed the mass in the right atrium. The stalk of mass was located near junction of the right atrium and inferior vena cava by cavography. He was operated upon using extracorporeal circulation. The tumor originated from inferior vena cava, measuring 8.5×5.5×4.8cm in size, 130g in weight, was successfully removed. Partial defect of anterior wall on the inferior vena cava was reconstructed using Gore-Tex patch. Histologically, the tumor was composed of the spindled cells with arranged bundles. Immunohistochemically, they were positive for Dessmin and Vimentin. Seven months after the surgery, he has been followed at OPD. In review of the Japanese literature to our knowledge, only 14 cases were reported including this case.

OBJECTIVESystemic and myelotoxic effects of 2,3,7,8-tetrabromodibenzo-p-dioxin (TBDD) were examined by the single administration of TBDD by gavage to rats.

METHODSFifteen Wistar rats of both sexes per group received 0, 10, 30, 100 or 300 μg TBDD/kg body weight. Rats surviving to the scheduled necropsy on Days 2, 7 and 36 after TBDD administration were examined for growth rate, organ weight, hematology, histopathology and adipose tissue levels of TBDD.

RESULTSThree 300 μg/kg-dosed females died on Days 21, 23 and 27, and exhibited a marked decrease in body weight, severe thymic atrophy, decreased bone marrow hematopoiesis and hemorrhage in the subarachnoid space of brain and spinal cord. TBDD-dosed surviving rats exhibited growth retardation, decreased bone marrow hematopoiesis, decreases in red blood cell counts, hemoglobin concentrations, and hematocrit values, an increase in reticulocytes and decreases in platelet counts, white blood cell counts and eosinophils. These signs suggested TBDD myelotoxicity. Splenic extramedullary hematopoiesis was increased in both sexes given TBDD, whereas atrophy of the splenic white pulp occurred only in TBDD-dosed females. Marked decreases in body weights and the size and weight of the thymus, severe thymic atrophy and death in TBDD-dosed females suggested a wasting syndrome. The adipose tissue level of TBDD culminated on Day 7 and decreased to 20-30% of the Day 7 level on Day 36.

CONCLUSIONSThe TBDD-induced effects were characterized by a wasting syndrome and myelotoxicity that appeared at the dose levels of 30 μg/kg and higher and caused death in 300 μg/kg-dosed females.