Pulmonary involvement of peripheral T-cell lymphoma manifesting as crazy paving pattern.

Crazy paving pattern is a finding on computed tomography of the chest that is characterized by interlobular septal thickening and ground-glass opacities. Though classically associated with pulmonary alveolar proteinosis, the differential diagnosis for this pattern is broad, and initial workup includes bronchoscopy with bronchoalveolar lavage to evaluate for malignancy, diffuse alveolar hemorrhage, pulmonary alveolar proteinosis, infection, and eosinophilic pneumonia. Herein we present an unusual case of peripheral T-cell lymphoma not otherwise specified (PTCL NOS) with pulmonary involvement that demonstrated crazy paving pattern. The diagnosis was confirmed after cytology from bronchoalveolar lavage revealed atypical lymphocytes with an immunologic profile consistent with the patient's known PTCL NOS.