Diagnostic Controversies in Vascular Proliferations of the Thyroid Gland

Abstract

Vascular lesions are one of the most controversial issues in thyroid pathology. The differential diagnosis includes benign lesions on one side, i.e., endothelial reactive hyperplasia (Masson's "hemangioma") in goiter and hemangioma, and malignant tumors on the other, i.e., angiosarcomas and undifferentiated (angio)sarcomatoid carcinomas. Benign reactive endothelial hyperplasia with atypias mimicking malignant tumors may occur in long-standing nodular goiter, as a result of spontaneous hemorrhage followed by granulation tissue and fibrous organization. Alternatively, it may follow a fine-needle aspiration biopsy (FNAB) procedure. Angiosarcoma is a rare primary malignant thyroid tumor, mainly observed in endemic goiter areas displaying morphologic and phenotypical similar to those typical of angiosarcomas in other locations (including focal cytokeratin expression). The distinction between angiosarcoma and (angio)sarcomatoid anaplastic carcinoma is difficult and the true existence of angiosarcoma has been challenged. Other extremely rare vascular lesions or mimics in the thyroid include benign hemangioma and pseudo-angiosarcomatous variant of medullary carcinoma. The differential diagnosis between benign and malignant vascular conditions in FNAB material is extremely challenging, and the cytopathology report should be remarkably cautious, especially in poorly cellular and highly hemorrhagic cases: atypias in endothelial cells are not per se indicative of malignancy, being a common feature of reactive endothelial hyperplasia in infracted goiter nodules as well.

Angiosarcoma of the Thyroid Gland: A Case Report

“…Focal solid undifferentiated areas are invariably present consisting of spindle cells arranged in fascicular pattern reminiscent of the most common morphologic pattern encountered in an anaplastic carcinoma [7,8]. This latter feature make many experienced pathologists unfamiliar with this lesion to regard it as a variant of anaplastic carcinoma or other sarcoma.…”

Angiosarcoma Thyroid: Case Report and Review of Literature

“…Immunopositivity for vascular markers for example, CD31, CD34, factor VIII related antigen, and absence of epithelial markers, greatly helps in diagnosis. But the distinction between angiosarcoma and anaplastic sarcomatoid carcinoma is difficult [2] [9]. Immunonegativity for thyroglobulin supports a diagnosis of angiosarcoma which is not found anaplastic carcinomas, confirming that these lesions are unrelated malignant tumors [10].…”

“…As regards adjuvant therapy, some say that, after the radical excision of the tumor, radiotherapy and then chemotherapy are indicated [6]; others claim that, if the tumor is not corroded surgically and if the patient is subjected to radiotherapy and chemotherapy it represents only a palliative treatment because the first step of choice is radical surgical excision of the tumor. Regarding prognosis of the tumor, poor outcomes occur mostly with extracapsular tumor spread and distant metastasis [2] [4] [6] [8]. Data on survival are sparse.…”

“…The various types of sarcomas found in thyroid gland are liposarcoma, angiosarcoma, leiomyosarcoma, dendritic cell sarcoma [1]. Various vascular malignant tumors of the thyroid include angiosarcomas or undifferentiated angiosarcomatoid carcinomas [2].…”

“…Difficulties are also encountered by the pathologist due to its histopathological similarity to angiomatoid variant of anaplastic carcinomas [2]. Aggressive nature of the tumor requires an early diagnosis and proper management of the case.…”