Secondary pulmonary alveolar proteinosis: a confusing and potentially serious complication of hematologic malignancy.

OBJECTIVE: We analyzed the computed tomography and clinical findings of pulmonary alveolar proteinosis secondary to hematologic malignancy. MATERIALS AND METHODS: Seven patients with hematologic malignancy and pathologically proven secondary pulmonary alveolar proteinosis were identified from 2000 to 2007. Six had chest computed tomography scans, which were analyzed retrospectively; medical records were also reviewed. RESULTS: Patient age ranged from 30 to 54 years. Four had chronic myelogenous leukemia, 1 had myelodysplastic syndrome, and 1 had cutaneous T-cell lymphoma. As in idiopathic pulmonary alveolar proteinosis, geographic ground-glass opacities with or without septal thickening were most common (5/6). No axial or zonal predominance was present. Two patients died from respiratory failure. CONCLUSIONS: It is important to consider secondary pulmonary alveolar proteinosis as a cause of geographic ground-glass opacities and septal thickening in a patient with hematologic malignancy. Whereas idiopathic pulmonary alveolar proteinosis has a low mortality rate, the death of 2 of our 6 patients implies that secondary pulmonary alveolar proteinosis may have a worse prognosis. Our case of secondary pulmonary alveolar proteinosis associated with cutaneous T-cell lymphoma is the first described in the literature.

Radiologic and pathologic features of bronchiolitis.

OBJECTIVE: The purpose of this article is to describe and illustrate the clinical, pathologic, and imaging features of the inflammatory and fibrotic forms of bronchiolitis. The CT features presented in this article represent the typical features associated with each entity. CONCLUSION: Direct signs of bronchiolitis include centrilobular nodules and tree-in-bud pattern. Indirect signs include mosaic attenuation and air trapping. Although classic examples of each entity exist, there can be substantial overlap in the appearances, and distinguishing among these entities is not always possible. When high-resolution CT features overlap, clinical details will usually help to narrow the differential diagnosis.