Thyroid perivascular epithelioid cell tumor: A rare case report

Abstract

Background: Perivascular epithelioid cell tumors (PEComas) are rare mesenchymal tumors with histological and immunophenotypic characteristics of perivascular epithelioid cells, characterized by smooth muscle and melanocytic markers. Herein, we report a case of PEComa originating in the thyroid gland.

Case presentation: A 36-year-old woman presented with a thyroid nodule detected on physical examination that gradually enlarged during a 3-year follow-up period. The patient underwent a unilateral thyroidectomy after completing the relevant preoperative investigations. Postoperative pathological immunohistochemical staining was positive for cathepsin K, microphthalmia-associated transcription factor (MiTF), and smooth muscle actin (SMA). The patient was diagnosed with a perivascular epithelioid tumor. The patient's condition stabilized after a short-term follow-up.

Discussion: Perivascular epithelioid cell tumors (PEComas) of the thyroid gland are extremely rare, with only one case reported in the literature. There are no clear criteria for distinguishing benign and malignant PEComas of the thyroid gland. This case suggests that surgical resection is a good management option for this patient, and long-term follow-up is needed to observe the outcome.

Conclusion: Surgical resection is safe and feasible for PEComas of the thyroid gland.

Keywords: Case report; PEComas; Short-term prognosis; Surgical resection; Thyroid gland.

Fig. 1

Ultrasound imaging of the thyroid gland.

Fig. 2

Intraoperative images showed a thyroid tumor located anterior to the trachea and with an incomplete envelope.

Fig. 3

Most of tumor cells were epithelioid, with round ovoid nuclei, abundant cytoplasm, and eosinophil-rich tumor cells in radial rows around blood vessels; SMA, MiTF, Cathepsink positive immunohistochemistry.