Epithelioid angiosarcoma of the thyroid gland without distant metastases at diagnosis: report of six cases with a long follow-up.

We present six cases of epithelioid angiosarcomas (EAS) of the thyroid gland without distant metastases at diagnosis and with a long follow-up. We retrieved the six consecutive cases of thyroid EAS between 2005 and 2011. Gender was equally represented; median age was 60 years (range 53-68). One case was post-irradiation and another post-exposure to vinyl chloride. Median diameter was 6 cm (range 5-13). Regional nodal metastases were present at onset in two cases. All the cases expressed CD31 in a membranous pattern. CD34 was always negative. All the patients underwent complete surgical resection. Neoadjuvant chemotherapy was applied in one case and adjuvant chemotherapy in four cases with adjuvant radiation therapy in one case. Follow-up until June 2015 was available in five cases. Median follow-up was 59 months (range 9-82). Three patients relapsed. Two patients (the post-irradiation and post vinyl chloride exposure cases) died of disease after 36 and 9 months, after a local relapse soon followed by distant metastases. Three patients are alive and well after 59, 70, and 82 months, including a patient with a relapse treated with neoadjuvant chemotherapy and surgery. In conclusion, thyroid EAS without distant metastases at diagnosis are very rare tumors. They all expressed CD31, while CD34 was always negative. Distant metastases developed together with local relapse, rapidly followed by death. Inadequate surgery contributed to poor outcome. Cases with previous exposure to irradiation and vinyl chloride showed a particularly poor behavior.