In lung transplant patients, most infections produce radiographically diffuse or lobar infiltrates. Solitary nodules suggesting neoplasm may arise in lung transplant patients with lung infections. We describe a 45-year-old woman who underwent bilateral lung transplantation to treat bilateral bronchiectasis and lung fibrosis resulting from Hodgkin disease. Five months later, a solitary mass was identified on chest radiograph in the left upper lobe and left superior mediastinum. Low-power examination of wedge biopsies of the mass showed a florid proliferation of cells with clear to bubbly to eosinophilic cytoplasm and moderate nuclear atypia, proliferating fibroblasts, and necrosis, suggesting a clear cell carcinoma (possibly metastatic renal cell carcinoma). Intranuclear inclusions compatible with cytomegalovirus were identified on high-power examination and confirmed by immunohistochemistry. In lung transplant patients, a cytomegalovirus infection may mimic malignancy both radiographically and on initial histopathologic examination.