Angiosarcoma of the parotid gland arising in a congenital nonirradiated hemangioma. A case with adverse outcome

In a recent issue of this Journal, we have described a case of primary angiosarcoma of the parotid arising in a benign congenital haemangioma (1). The patient had been treated with surgical resection and adjuvant radiotherapy. At the time of publication, the patient was well and disease free after two years from the initial diagnosis of malignancy. Unfortunately, 1 year later the patient presented with a profuse rectal bleeding. At laparotomy the ileum appeared hemorrhagic and a tract of 25 cm was resected. Pathological examination of the surgical specimen revealed a small (5mm) mucosal nodule ulcerating the overlying epithelium. The nodule had identical histological features of the primary parotid tumor (Fig.1) and a diagnosis of metastatic angiosarcoma was made. The patient underwent CT scan total body to evaluate the extent of metastatic disease, and a large pelvic mass encasing the bladder and the ovaries was found together with pulmonary nodules. The pelvic mass was excised and, at histology, showed the same features of the parotid and ileal lesions (Fig.2). At present, 43 months after initial diagnosis of malignancy, the patient is alive with diffuse metastatic disease (lung, skin, brain and abdomen). Angiosarcoma (AS) arising in benign hemangioma are rare and most of them are post-irradiation neoplasms, which are usually well differentiated low grade tumors (2). Recently Rossi et al (3) reported a small series of four cases of AS arising in non-irradiated benign hemangiomas in various organs. All cases in this series were recent cases, with a follow up of few months. However, it is noteworthy that in three out four patients the tumor had features of high grade epithelioid AS, like in our case. Although more cases are needed to explain the clinico-biological behavior of these tumors, we believe that AS arising spontaneously in benign hemangiomas are in most cases high grade neoplasms, morphologically and clinically different from the post-irradiation tumors