Castleman's disease is a rare disorder generally characterized by a mediastinal nodule, with a great variety of alternative presentations regarding age, clinical manifestations and evolution. This case report describes a 40-year-old female patient presenting with uncharacteristic chest pain for a few years. A chest X-ray revealed a hypotransparency on the right side. Computed tomography and pulmonary arteriography did not elucidate the diagnosis, which was made through surgical resection and anatomopathological examination of the nodule, which presented characteristics of angiofollicular hyperplasia, or Castleman's disease. This article emphasizes the importance of adding this disease to the list of morbidities in the differential diagnosis of pulmonary solitary nodules.