Skin Metastasis Occurring 30 Years After Thyroidectomy for Papillary Thyroid Carcinoma

Abstract

The skin is an extremely rare site of metastasis from papillary thyroid carcinoma (PTC) and is linked to underlying disseminated malignancy, which reflects a dismal prognosis. We present the case of a 70-yearsold Saudi female who presented at our clinic with an eight-month history of two painful and itchy skin nodules over the scalp and the medial aspect of the right arm. She had a history of total thyroidectomy for PTC 30 years prior. Computed tomography-positron emission tomography showed multiple fluorodeoxyglucose avid lung and skeletal metastases. This case highlights the fact that skin nodules in a patient with a history of PTC should be assessed carefully with a high suspicion of skin metastasis to avoid any delay in treatment.

BRAFV600E and TERT promoter C228T mutations on ThyroSeq v3 analysis of delayed skin metastasis from papillary thyroid cancer: a case report and literature review

“…Skin metastasis from PTC has been described in prior case reports, but the incidence remains extremely low. Most skin metastases are located in the scalp, face, and neck, which is likely due to the rich lymphatic and vascular supply in these areas [5][6][7][8][9]. Other locations such as the medial arm and supraclavicular fossa have also been described [6,10].…”

“…Similar to most distant metastases, the potential mechanisms underlying skin metastasis include direct extension and hematogenous or lymphatic spread of the primary tumor [7,8]. Additionally, there have been reports of metastatic skin lesions away from the thyroidectomy scar but along the prior core needle biopsy tract, suggesting needle-tract seeding as another possible route of metastasis [11,12].…”

“…The skin lesion itself may manifest as a flesh-colored or pigmented papule, plaque, or nodule with or without ulceration [7,8]. Because its appearance can vary and resemble other skin lesions, diagnosis can be challenging without a high suspicion, especially since these metastases can occur several years after remission of the primary cancer.…”

“…Because the condition is rare, there are no standardized guidelines regarding treatment. The treatment usually involves excision of the metastatic site, and additional therapies including RAI, external-beam radiotherapy, or targeted therapy such as sorafenib or vandetanib may be used [6,7]. The utility of adjuvant therapy depends on several factors including the iodine avidity of the tumor, the extent of residual disease, and the molecular characteristics of the lesion.…”

“…These cases are reported mainly through case reports and demonstrate a variable presentation in terms of location of the metastatic lesion, disease state, and the timing of discovery in relation to the initial diagnosis of PTC. The onset of skin metastasis ranges from within 1 year to as late as 30 years after the initial diagnosis of PTC, with the median onset of 8.25 years from the initial treatment [7].…”