A case of epithelioid hemangioma of the right third rib in a 55-year-old man

We report a case of epithelioid hemangioma in a relatively uncommon location but with typical features in a 55-year-old man. A 55-year-old man was referred to our hospital with an asymptomatic mass of the right third rib, after the mass was incidentally found during a health checkup in April 2014. The mass had been gradually growing in size during the previous 1 year and 8 months. On physical examination, the mass was not palpable. On a plain radiograph, a bone tumor with ballooning was identified on the right third rib. Chest computed tomography revealed a mass protruding into the thoracic cavity from the right third rib with cortical destruction. Surgical resection of the tumor was performed because the tumor had been gradually increasing in size. The tumor size was 35×25×20 mm. Histopathologically, the tumor was proliferating within the bone and replacing the marrow cavity. The tumor was composed of small to medium sized arteriolar vessels lined by flat to swollen endothelial cells with prominent nucleoli. The tumor stroma was filled with mixed inflammatory cells with massive eosinophils. The tumor cells did not show apparent nuclear pleomorphism. No necrotic area or mitosis was observed. Immunohistochemically, tumor cells were diffusely positive for CD31 and were focally positive for AE1/AE3, but were negative for CD34, D2-40, and CAM5.2. MIB-1 labeling index was almost 0%. Based on these findings, a final diagnosis of epithelioid hemangioma of the rib was made. The patient is disease-free at 5 months after surgery. However, further long-term follow up is needed.