Skull metastasis from thyroid cancer: review of current literature and a unique case of poorly differentiated thyroid metastasis

Abstract Background and purpose Metastatic lesions to the skull are relatively common in cancer patients. Although often asymptomatic, such lesions may lead to severe catastrophic outcome when located near important anatomical structures. The most frequent primary sites of skull metastasis include the breast, lung, prostate and lymphomas. Metastasis from thyroid cancer, however, is extremely rare. Materials and methods We conducted a comprehensive literature review using PubMed, focussing on thyroid cancer with bone metastasis over the past ten years with primary emphasis on literatures discussing skull bone metastasis from thyroid cancer. Additionally, we present a rare case of a 59-year-old male with poorly differentiated thyroid cancer (PDTC) metastasizing to the skull and review current treatment strategies. Conclusion Currently, no standardized treatment exists for skull bone metastasis originating from thyroid cancer. Most literature suggests a multidisciplinary approach for these patients, including en bloc resection of the skull bone metastasis with total thyroidectomy and lymph node dissection whenever feasible, to improve survival outcome. Key messages Skull bone metastasis of thyroid origin is a rare encounter Skull metastases of thyroid origin are most commonly associated with follicular and papillary carcinomas Aggressive multidisciplinary treatment, including en bloc resection of the skull bone metastasis and total thyroidectomy with lymph node dissection, is recommended