Pulmonary angiosarcoma is a rare and fatal entity. It can be either primary or metastatic. Its diagnosis is often challenging due to non-specific symptoms and low clinical suspicion. Here we present a case of metastatic pulmonary angiosarcoma of unknown primary. A 76 year-old male with medical history significant for coronary artery disease, systolic heart failure, peripheral vascular disease, and known arteriovenous malformations of the gastrointestinal tract, presented to the hospital with a three-week history of melanotic stools, hemoptysis, and dyspnea on exertion. Computed tomography of the chest demonstrated diffuse mixed ground glass and semisolid nodules with halo sign (Figure 1). He subsequently underwent bronchoscopy with bronchoalveolar lavage, which was suggestive of alveolar hemorrhage on initial aliquot; however, due to oxygen desaturation, the procedure was prematurely aborted. Fluid analysis demonstrated macrophage predominance. Cultures and cytology were negative for infection and malignancy, respectively. Autoimmune workup was significant for a positive antinuclear antibody 1:160 with speckled pattern, but otherwise unrevealing. Due to worsening respiratory status, the patient was treated with pulse dose steroids for possible anti-neutrophil cytoplasmic antibody negative vasculitis. He underwent surgical lung biopsy that revealed a high grade angiosarcoma. His hospital course was complicated by gastrointestinal bleeding requiring multiple transfusions. Upper endoscopy and colonoscopy were unrevealing. Enteroscopy demonstrated multiple arteriovenous malformations, presumably primary for metastatic pulmonary angiosarcoma, but this was unable to be confirmed due to patient's poor functional status. Paclitaxel was given inpatient with significant improvement in hemoptysis, melena, and reduction in transfusion requirement. He was eventually discharged home. Angiosarcoma is a rare entity that accounts for <2% of all sarcomas. The most common locations for the primary tumor are skin, heart, liver, breast, bone, and gastrointestinal tract. Metastasis occurs in more than half of the patients and commonly affects the lung. Patients usually present with non-specific respiratory symptoms including hemoptysis, dyspnea, and cough, which may delay the diagnosis. Radiological manifestations include concurrent ground-glass and solid nodules in the lung with variable sizes and peripheral distribution. The definitive diagnosis requires lung biopsy. Due to their aggressive nature and poor response to chemotherapy, the overall prognosis remains poor, with a five-year survival rate of approximately 35-40%.
