Pulmonary Dirofilariasis and Transitional Cell Carcinoma: Benign Lung Nodules Mimicking Metastatic Malignant Neoplasms

• Pulmonary dirofilariasis occurred in a 79-year-old man with known transitional cell carcinoma. Bilateral lung nodules suggesting metastatic carcinoma were resected and subsequently identified as being caused by Dirofilaria immitis . The typical features of human dirofilarial infection are reviewed and contrasted with the unusual clinical findings in this patient. ( Arch Intern Med 1983;143:1259-1260)