TRICHOSPORON BEIGELII PNEUMONIA IN PATIENTS WITH HEMATOLOGIC MALIGNANCIES

Trichosporon belgelii is a causative agent of hypersensitivity pneumon ia in immunocompetent individuals and of invasive pneumonia in immunoc ompromised patients. The actual incidence and clinical manifestations of T begelii pneumonia are obscure because the diagnosis is sometimes difficult. We studied eight patients with T beigelii pneumonia diagnos ed by immunohistochemical investigation of lung tissue sections and/or isolation of the organism from the lung, sputum, or blood. All patien ts had underlying hematologic malignancies for which they had received cytotoxic chemotherapy, resulting in profound neutropenia. The clinic al manifestations were persistent fever unresponsive to broad-spectrum antibiotic therapy, cough, bloody sputum, and rapidly progressive dys pnea. The chest radiographs showed diffuse alveolar infiltrates in fou r patients, diffuse interstitial infiltrates in one, patchy reticulono dular infiltrates in one, and focal alveolar infiltrates in two. Histo pathologic examination demonstrated numerous centrally necrotic foci w ith minimal cellular inflammatory reaction, intra-alveolar hemorrhage, and edema. Trichosporon beigelii consisting of both yeast and hyphal forms was located predominantly in the alveolar vessels. In neutropeni c patients with hematologic malignancies, this fungus appears to enter the lung not only through the airways but also via the hematogenous r oute. In vitro susceptibility testing indicated borderline susceptibil ity to amphotericin B and showed that some azoles were active against T beigelii at safely achievable serum concentrations.