Pulmonary intravascular bronchoalveolar tumor (IVBAT) also recognized as pulmonary epithelioid hemangioendothelioma, is a rare malignant vascular tumor of unknown etiology. IVBAT is a tumor of multicentric origin. The lungs are rarely involved, with only 50 cases of pulmonary IVBAT described in the literature. The prognosis is very unpredictable, with life expectancy ranging from 1 to 15 years. We report an unusual case of pulmonary IVBAT that recurred in the lung with metastasis to the mediastinum diagnosed by mediastinoscopy.
A 58-year-old woman presented with right lateral costal margin tenderness of 4 weeks duration that she first noticed while working in her yard. She denied other symptoms. In 1984, she presented with bilateral lung nodules for which a left lower lobe resection was performed. Histology revealed pulmonary IVBAT. She was not offered therapy. Serial chest radiographs demonstrated regression of the lung nodules. She never smoked. On examination, she was in minimal distress due to pain. Her vital signs were normal. She had no lymphadenopathy. She had digital clubbing and tenderness along the right costal margin. There was dullness to percussion in the right infrascapular and lower axillary region with inspiratory crackles. A radiograph and a computerized tomography of the chest revealed a well-circumscribed homogenous mass in the right upper-lobe, posterior segment with mediastinal lymphadenopathy. A positron emission tomography scan revealed intense fluoro-D-glucose uptake in the mass and in the mediastinal lymph nodes. The patient underwent mediastinoscopy which confirmed the histologic diagnosis of pulmonary IVBAT consistent with her previous disease.
Pulmonary IVBAT was first described by Dail et al in 1975(1). The tumor was thought to be an aggressive form of bronchoalveolar carcinoma with a propensity to invade adjacent vasculature. Immunohistochemistry and electron microscopic studies demonstrated that IVBAT is of endothelial origin and the tumor was renamed epithelioid hemangioendothelioma. IVBAT is a rare vascular tumor of low-grade malignancy, although cases of more aggressive behavior have been reported. IVBAT is a tumor of multicentric origin that can arise from liver, bone, and soft tissues simultaneously or sequentially. However, lungs are rarely involved. IVBAT is often diagnosed incidentally, as patients are usually asymptomatic or have minor symptoms at the time of diagnosis. There is no single effective treatment. Reports show that some patients respond to chemotherapy with carboplatin plus etoposide while others demonstrate a partial response to interferon therapy(1,2). The prognosis is very unpredictable. Spontaneous regression of the tumor has described for up to 15 years after initial diagnosis without any treatment. Extensive spread to the intravascular, endobronchial or pleural regions as well as the presence of liver nodules and peripheral lymphadenopathy may predict a worse prognosis. The life expectancy may vary from 1 to 15 years. In this case, recurrence of lung IVBAT occurred after 20 asymptomatic years. Our patient had minor symptoms with an incidental diagnosis of lung nodules at both presentations. The current presentation appears to be more aggressive involving mediastinal lymphnodes along with the lung mass. Mediastinoscopy yielded the diagnosis, unlike previous case reports.
Pulmonary IVBAT is thought to be a low grade malignant tumor. However, the prognosis is variable, and the predictability of recurrence is unknown. In our case, we find that the recurrence of this disease with aggressive presentation may occur after a prolonged period of remission.
T. Chen, None.