Primary Angiosarcoma of Humerus – A Case Report and Literature Review

Introduction: Osseous angiosarcoma is a very rare tumor of bone with aggressive behavior, propensity for recurrences, and distant metastasis. The etiology of osseous angiosarcoma is uncertain; however, specific risk factors have been recognized. The diagnosis of angiosarcoma of bone demands multimodality imaging in conjunction with histopathological and vascular marker evaluation to aptly differentiate them from other vascular tumors. Treatment of osseous angiosarcoma remains controversial. Case Report: A 53-year-old male presented with pain and swelling of the right upper 1/3rd of the arm following heaviness while lifting weight for 3 months. He had a history of significant weight loss and appetite with no history of inciting trauma or irradiation in the past. On examination, a diffuse swelling was noted in the right shoulder and right scapular aspect with varied consistency and ill-defined borders and margins. The skin over the swelling was stretched and shiny with dilated engorged veins over it. The plain radiograph of the right shoulder with humerus revealed a large expansile lytic soft-tissue mass in the right proximal humerus with a wide zone of transition without sclerotic margins. Magnetic resonance imaging showed T1 hypointense, T2/PDFS hyperintense large well-defined expansile lytic lesion with multi-loculated cysts, and multiple blood-fluid levels involving right proximal humerus. The patient underwent an incisional biopsy which exhibited angiosarcoma of the humerus. The patient was treated with six cycles of chemotherapy with a mesna, doxorubicin, ifosfamide, and dacarbazine regimen. The patient was still under follow-up. Conclusion: Being a rare clinical entity, controversy exists in angiosarcoma of humerus regarding its etiology and recommended management protocols. Histopathology and immunohistochemistry remain the gold standard in differentiating osseous angiosarcoma from other osseous vascular tumors. The treatment protocol has to be standardized to