Baritosis of the mediastinal lymph nodes

Abstract

A 49-year-old man, a nonsmoker, was admitted with a 2-week history of nonproductive cough. He had been a construction worker digging up wells in an Aegean island where barite ore is present. There was no history of tuberculosis or sarcoidosis. Physical examination and routine laboratory investigation were unremarkable. Chest roentgenogram showed hilar lymphadenopathy. Noncontrast computed tomography of the chest (Figs 1 and 2) revealed multiple, almost symmetrical, 7to 20-mm high-density structures compatible with lymph nodes in the pretracheal and paratracheal areas (Fig 1), subcarinal area (Fig 2), around the hilum bilaterally, and in the inferior-posterior mediastinum, resembling a mediastinal lymphangiogram after intralymphatic injection of iodine-containing contrast material. Bronchoscopy was unremarkable. Mediastinoscopy and biopsy of the mediastinal nodes showed sinus histiocytosis with no evidence of malignancy. Further roentgenogram fluorescence examination after ashing the surgical specimen at 600°C for 24 hours showed that 0.1% of its mass was barium. It has been postulated that the accumulation of barium in the patient’s mediastinal lymph nodes was due to his long-standing occupational exposure to barite dust. Barite is an insoluble ore (BaSO4), which is the greatest single source of the element barium. The dust was inhaled by the patient and was transferred from the bronchial mucosa to the mediastinal lymph nodes through the pulmonary lymphatics. It is well known that the metals with high atomic number (Z), such as barium with Z 56 and iodine with Z 53, absorb X-rays. Address reprint requests to Dr Dosios, 2 Chatzigianni Mexi Str, 11528 Athens, Greece; e-mail: dosiosth@internet.gr. Fig 1. Fig 2.