Pulmonary alveolar proteinosis in a 67-year-old woman with Wegener's granulomatosis.

Mycophenolate mofetil (MM) is commonly used in patients with autoimmune diseases or who have undergone transplantation. Common side effects of MM include anemia, leukopenia, mucositis and opportunistic infections. We report an unusual case of pulmonary alveolar proteinosis (PAP) in a 67-year-old woman on MM for Wegener's granulomatosis (WG). PAP is a disease characterized by defects in macrophage-mediated processing of surfactants, leading to accumulation of periodic acid-Schiff (PAS)-positive lipoproteinaceous material within the alveolar spaces.