(Virtual ) Metastatic Papillary Thyroid Carcinoma to the Skin With Unusual Vascular Proliferation: A Rare Case Report

Abstract

Vascular proliferations have been classified according to their pathogenesis into primary vascular tumors and reactive vascular malformations. Vascular tumors represent neoplastic growth of vascular endothelial cells, whereas vascular malformations are structural anomalies of the blood vessels without neoplastic proliferation. Reactive cutaneous angiomatosis has been associated with inducing factors such as radiation exposure, and circulation blockage and when present warrants a workup for potential causes of the latter. Herein, we report an 89-year-old male retired dentist with a history of hypothyroidism, potential occupational radiation exposure, and prostate cancer treated with radiotherapy more than 20 years ago. He presented with a 3-year stable asymptomatic eruption, characterized by branching linear ill-defined, red-purple patches on the chest, which were biopsied demonstrating well-formed, thin-walled dilated vessels with plump endothelial cells in the upper dermis. The Vessels were highlighted by CD31, D2-40, Erg-1, WT-1 and were negative for HHV-8 and C-MYC, ruling out Kaposi sarcoma, radiation-associated atypical neoplasm and supporting the diagnosis of reactive angiomatosis. The patient was also noted initially to have a 2cm mass on the left submandibular neck area and was referred to otolaryngology but could not complete the referral due to insurance issues. Four months later, the patient presented with several new subcutaneous nodules on the chest, which were biopsied revealing metastatic adenocarcinoma of unknown primary, but favored to be thyroid in origin as the tumor cells expressed TTF1, PAX-8, and AE1/AE3. Thyroid metastases to the skin are uncommon and rarely present clinically as an unusual vascular proliferation resembling Kaposi’s sarcoma. Patients with cutaneous reactive angiomatoses should undergo a thorough investigation to rule out the possibility of associated systemic diseases or localized conditions that may cause vascular occlusion.

Financial Disclosure:
No current or relevant financial relationships exist.

Published in: ASDP 59th Annual Meeting, USA

Publisher: The American Society of Dermatopathology
Date of Conference: October 17-23, 2022