Electron microscopic analysis of an angiosarcoma of the thyroid from a non-Alpine endemic goiter region: A case report and brief review of the literature

Abstract

Angiomatoid tumors of the thyroid gland are rare endocrine neoplasms, which exhibit an aggressive behavior. Angiosarcomas of the thyroid are generally reported from the European Alpine region and have a histogenesis that has been under debate for a number of years. The current study presents a rare case of angiosarcoma of the thyroid in a 62-year-old Turkish female. The patient had a 10-year history of goiter and was from the Black Sea region, an endemic goiter region of Turkey. The patient was not taking any medication at the time of admission and swelling had been observed on the right side of the neck throughout the previous few months. Thyroid function tests, which analyzed the levels of thyroid-stimulating hormone, thyroxine and triiodothyronine, were within the normal limits, however, the histopathological findings were consistent with an angiosarcoma of the thyroid. The patient rejected the complementary surgery and chemotherapy options, and is currently disease-free (as per the 15-month follow-up). The current study describes a case of angiosarcoma that was characterized by Weibel-Palade bodies, and light microscopy and immunohistochemical findings, as well as an endothelial origin, which was demonstrated via electron microscopy. To the best of our knowledge, this is the first reported case of angiosarcoma of the thyroid in a patient from Turkey to be validated by electron microscopy. Furthermore, this case is one of the few reported thyroid angiosarcoma cases in a non-Alpine region.

Primary Thyroid Angiosarcoma with Tracheal Invasion

“…Kaur et al reviewed a number of thyroid angiosarcoma cases and determined that tests for CD31 were positive in 30 of 30 cases, tests for CD34 were positive in 15 of 28 cases and tests for factor VIII were positive in 39 of 41 cases (9). Our patient also tested positive for endothelial vascular markers such as CD31, CD34, vimentin and factor VIII; however, the test for TTF-1 was negative, which was consistent with all previously described cases of thyroid angiosarcoma (1,(11)(12)(13)(14).…”

“…Therefore, in some cases, TTF-1 is used to exclude the coexistence of other thyroid cancers such as follicular carcinoma (1,11). Immunohistochemical staining for endothelial vascular markers such as CD31 and factor VIII-related antigen was observed to be the most consistently positive for diagnosis (1,3,4,(9)(10)(11). Kaur et al reviewed a number of thyroid angiosarcoma cases and determined that tests for CD31 were positive in 30 of 30 cases, tests for CD34 were positive in 15 of 28 cases and tests for factor VIII were positive in 39 of 41 cases (9).…”

“…Sarcomas occur in 1% of all malignancies while angiosarcomas are rarer, constituting less than 1% of all sarcomas (1,2). Thyroid angiosarcoma is not well known in many countries and most cases are found in the alpine regions of Europe, including Switzerland, North Italy and Austria (2)(3)(4).…”

Non-Alpine Thyroid Angiosarcoma After Radiation Exposure: A Case Report

“…Angiosarcoma of the thyroid has unclear pathophysiologic mechanisms (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20). It has been associated with goiter, often stemming from iodine deficiency, and therefore thought to be the reason for most cases being found in Alpine regions (18).…”

“…It will often recur despite treatment, and seemingly localized disease may instead have micrometastases that escape detection at initial diagnosis and later arise as "postoperative early systemic metastasis" (5). In gross morphology, thyroid angiosarcomas have been described as poorly encapsulating and infiltrative, although there are cases in which tumors are well encapsulated (2,4,13).…”