Pneumocystis pneumonia (PCP) is common in patients with HIV infection but may also
occur in patients with other causes of immunodeficiency, including hematologic and
solid malignancies.
To better describe the clinical picture of PCP as to maintain a high level of suspicion
in adequate cases, we studied 56 cancer patients with PCP and compared them to 56
cancer patients with bacterial pneumonia.
Among 56 PCP patients, 44 patients (78.6%) had hematologic malignancies (18 recipients
of bone marrow transplantation) and 12 patients had solid tumors. The time since diagnosis
was 24 months (range, 4 to 49 months). All patients with solid tumors and 20 patients
(45.4%) with hematologic malignancies were receiving steroids. Only six patients were
receiving PCP prophylaxis. The main symptoms were fever (85.7%), dyspnea (78.6%),
and cough (57.1%). Time from symptom onset was 7 days (range, 3 to 14 days). PCP presented
as severe pneumonia (Pao(2), 58 mm Hg [range, 50 to 70 mm Hg]) with bilateral interstitial
infiltrates (80.4%) and bilateral ground-glass attenuation (89.3%) by CT. Of the 24
ICU patients (42.9%), 16 patients (19.6%) required mechanical ventilation. Eleven
patients (19.6%) died. Compared to 56 patients with bacterial pneumonia, PCP patients
were more likely to have non-Hodgkin lymphoma and be receiving long-term steroids;
they had longer times since diagnosis, longer symptom duration, higher frequencies
of fever and of diffuse lung disease (diffuse crackles, bilateral infiltrates, and
hypoxemia), higher frequency of ground-glass opacities, and lower frequency of pleural
involvement.
PCP presents as subacute, febrile, hypoxemic, and diffuse pulmonary involvement in
patients with solid tumors or hematologic malignancies receiving long-term steroids.