Skin metastasis of papillary thyroid carcinoma: A case report and literature review

The present study reports a rare case of skin metastasis in a 26-year-old female patient with a history of PTC positive for the <i>BRAF</i> ^V600E mutation. During the 2.5-year follow-up period after the initial surgical treatment of PTC, no evidence of distant metastasis was found via thyroglobulin measurements, neck ultrasound, or neck and chest computed tomography. However, following this period, the patient reported two skin nodules on the left side of the neck. Ultrasound-guided punch biopsy was performed, and the pathology results demonstrated that the patient had skin metastases from the PTC. The patient received surgical resection and complete removal of nodules, and was subsequently discharged from the hospital. A literature review showed that there are numerous potential mechanisms for skin metastasis, and the treatments are diverse and dependent on the patient condition. While surgical treatment may effectively improve patient symptoms and prognosis, long-term surveillance for recurrence is recommended for high-risk cases. Skin metastasis of PTC should be suspected in patients who develop an upper body skin lesion with a history of PTC, even without evidence of disease metastasis. For high-risk patients with skin metastasis of PTC with <i>BRAF</i> and <i>TERT</i> gene mutations, long-term surveillance for recurrence should be recommended in cases with a poor prognosis, and further research of these cases should be conducted in the future to optimize surgical and medical care.