Pleural Pseudotumoral Mass Revealing an Extrapulmonary Pneumocystis carinii Infection

Pneumocystis carinii pneumonia (PCP) is the most common opportunistic infection in patients with AIDS, affecting 60% to 80% [1]. Extrapulmonary P. carinii infection is rare (2.5% of patients) and may occur in HIV-infected patients without evidence of PCP [1, 2]. The liver, spleen, bone marrow, lymph nodes, adrenal glands, thyroid, and ear appear to be the sites mainly involved, according to postmortem studies [2, 3]. Pleural involvement is rare and has been reported in cases clinically presenting as pneumothorax or pleurisy [4-6]. We report a case of a pleural pseudotumoral mass revealing P. carinii infection. A 30-year-old man with a history of iv drug abuse and tricuspid endocarditis was found to be HIV-positive in 1989. In 1993 esophageal candidiasis and digestive cryptosporidiosis were diagnosed, and since that time he had received didanosine (200 mg daily), spiramycin, and aerosolized pentamidine (300 mg monthly) as primary prophylaxis against PCP. He presented in January 1995 because of anorexia, a 3-kg weight loss, low-grade fever, night sweats, cough, and laterothoracic pain. On physical examination, the right basal vesicular murmur was decreased. Laboratory examination showed the following values: hemoglobin, 140 giL; platelets, 66,000/mm; leukocytes, 2,0001 mm' (neutrophils, 70%; lymphocytes, 19%; CD4 cells, 0/mm; and CD8 cells, 230/mm) ; p24 antigen, 300 pg/mL; lactate dehydrogenase (LDH), 463 lUlL; alanine aminotransferase, 69 lUlL; aspartate aminotransferase, 57 lUlL; fibrin, 3.6 giL; pH, 7.4; partial pressure of CO2 , 4 kPa; partial pressure of O2 , 13 kPa; HC03 , 18; and O2 saturation in arterial blood, 98%. Chest roentgenographic findings were considered normal. CT scanning revealed a heterogenous mass in the right pleural base (figure 1), with normal parenchyma and mediastinal adenopathies. A hypodense micronodular formation was observed in the spleen. Culture ofbronchoalveolar lavage fluid did not yield any microorganisms. Blood cultures were negative, as were tests for Cryptococcus, Toxoplasma, Aspergillus, Legionella, Mycoplasma, and Leishmania species. Cytomegalovirus was present only in urine. A transparietal needle biopsy of the pleural mass was performed, and examination of biopsy specimens revealed partial necrosis and numerous P. carinii organisms. The patient received iv trimethoprim-sulfamethoxazole, which produced a good initial response; however, 3 weeks later his condition worsened, and he died. Autopsy was not permitted. In large series of extrapulmonary P. carinii infections, pleural involvement has rarely been reported. Among 161 autopsied patients with AIDS, extrapulmonary P. carinii infection was detected in 2.5%, but no pleural localization was found [2]. In a review of 37 patients, spontaneous pneumothorax was reported in four cases; this was possibly secondary to pleural localization of P. carin ii,