Mechanisms of reaching the pleura and lung:
(1) rupture of a hepatic abscess into the pleural space (usual route)
(2) inhalation of cysts
(3) hematogenous spread
(4) lymphatic spread
Clinical findings:
(1) The patient may have preceding symptoms of intestinal involvement with a bloody diarrhea.
(2) The patient may have preceding symptoms of hepatic abscess with right upper quadrant pain and hepatomegaly.
(3) fevers
(4) pleuritic chest pain
(5) cough which may produce thick brownish material or fluid that is bile stained
(6) variable dyspnea
Imaging findings:
(1) hepatic abscesses
(2) pleural effusion, usually on the right side
(3) lung consolidation
(4) elevated right hemidiaphragm
Pleural fluid:
(1) usually thick and brown colored
(2) purulent exudate
(3) positive for E. histolytica antigen
(4) amebic trophozoites and cysts may be hard to identify
(5) PCR on the fluid is usually positive unless inhibitors are present
The patient will usually have serum antibody to E. histolytica.
Complications:
(1) bronchopleural fistula
(2) hepatobronchial fistula
(3) empyema from superinfection with bacteria
