Caso incomum de filariose linfática mediastinal com estenose da artéria pulmonar

E descrito um caso incomum de filariose linfática, devido a Wuchereria Bancrofti, com localização dos vermes nos linfonodos e linfáticos do mediastino. A intensa reação do conjuntivo mediastinal, provavelmente desencadeada por macrofilárias mortas, determinou no paciente - de 9 anos, residente em Belém, Estado do Pará - estreitamento do tronco e dos ramos principais da artéria pulmonar, defeito tido, inicialmente, como de natureza congênita. O exame histopatológico de duas dentre várias formações nodulares encontradas no mediastino, durante o ato operatório,permitiu, no entanto, estabelecer-se a verdadeira causa da alteração exibida pelo paciente. O achado representa uma formà curiosa de infecção por W. bancrofti, completamente inesperada, quando se considera que a prevalência da bancroftose é, hoje, muito baixa na cidade de Belém. Segundo dados oficiais, o índice de microfilaremia atingiu, em 1985, nessa cidade, cerca de 0,1% apenas, enquanto que, há algumas décadas, era ele estimado em mais de 10%. An unusual case of bancroftian filariasis caused by the presence of macrofilariae in the mediastinal lymphatic vessels is presented. The considerable tissue reaction developed in the mediastinum, probably in relation to products released by dead worms, provoked a severe constriction of the trunk and main branches ofthe pulmonary artery, which conducted to a initial diagnosis of congenital heart disease. The patient, a 9-year-old boy living in Belém-Pará, was admitted to the Belém Hospital and operated at the heart unit, on March 1983. Several fibrous masses were found in the anterior mediastinum, some of them being close to the bifurcation of the pulmonary trunk. The artery presented a severe constriction and a thickened wall. Two of the fibrous nodules were removed for histopathological examination and the sections showed that the masses consisted of lymph nodes surrounded by fibrous tissue and dilated lymphatic vessels. Lying inside the vessels there were numerous sections of filarial worms, recognized as mature females of Wuchereria bancrofti. Some of the worms had died and become calcified. Blood films obtained from the patient after the operation were negative for microfilariae. However, a member of his family, a 14-year-old sister, had been given a course of diethylcarbamazine (DEC), in January of the same year, because, in a routine examination, microfilariae of Wuchereria bancrofti had been demonstrated in her peripheral blood.