Progressively increasing density of the solid center of a ground-glass nodule in a solitary pulmonary capillary hemangioma: A case report.

Solitary pulmonary capillary hemangiomas (SPCHs) are recently recognized, rare benign lesions that form solitary nodules owing to capillary proliferation. These lesions are usually detected incidentally as small ground-glass nodules (GGNs) on computed tomography (CT), and progressively enlarge over time. The radiological distinction from peripheral lung cancers is particularly challenging. However, to date, there have been no reports on progressive changes in the central density of SPCH on CT. An asymptomatic 49-year-old man was referred to our hospital for an abnormal shadow that was detected on chest CT during medical check-up. He was subsequently followed-up with chest CT. The nodule increased in size, and the central area became progressively denser. He underwent surgery 5 years and 10 months after the first visit owing to suspicion of lung cancer. Despite the collapse of the surgical specimen by artifacts, histopathological examination revealed a diagnosis of SPCH; collagenous fibers were found in the walls of the intralesional capillaries. The patient is presently alive without any recurrence, 6 months after the operation. In this case, the SPCH demonstrated a GGN with progressively increasing density of the central solid area on the CT. This remarkable feature made the preoperative distinction from lung cancer particularly difficult.