A Rare Primary Thyroid Tumor with a Poor Prognosis Is Angiosarcoma

Primary angiosarcoma of the thyroid gland is a rare histological subtype of thyroid malignancy. This tumor is destructive and locally aggressive with a high risk of recurrence. Metastatic disease is associated with a poor prognosis. To our knowledge, this case is the 8th reported and officially documented in Turkey. A 66-year-old female patient with a 30-year history of thyroid goiter presented at the clinic with swelling in the throat and shortness of breath for two months. Neck ultrasonography revealed a hypoechoic nodular lesion measuring 8 × 6 cm with macro- and microcalcifications, which occupied the right lobe. Macroscopic examination revealed a nodular lesion measuring 9 × 9 × 7 cm in the right thyroid lobe with a smooth outer surface and a hard consistency. Graypurple nodules with significant hemorrhagic and necrotic areas, some of which exhibited calcification, were observed in the sections of this nodule. On histopathological examination, the neoplastic cells had slightly hyperchromatic, atypical, and equally sized nuclei. The atypical neoplastic cells also had partial trabecular structures and vascular spaces. Atrophy was observed in the surrounding thyroid tissue. During the immunohistochemical staining examination, CD31 was strongly positive in tumor cells while CD34, calcitonin, and thyroglobulin were negative in these cells. Thyroglobulin was positive in the atrophic thyroid tissue. Metastases of angiosarcoma were detected in cervical lymph nodes at all dissected levels. The significance of presenting this case lies in its ability to raise awareness among pathologists and clinicians who are knowledgeable about a rare thyroid tumor. This will aid early diagnosis and prompt treatment, increasing the chances of accurate diagnosis and ultimately improving survival outcomes.