Systematic review of site distribution of bone metastases in differentiated thyroid cancer

Background. Thyroid cancer is the fastest growing cancer in the United States. A small portion of differentiated thyroid cancers (DTCs; 2% to 13%) develop bone metastases, which can decrease a patient's survival rate by more than 60%. Methods. A systematic literature search of studies, including patients with DTC with bone metastases, was conducted by following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A case series of patients with DTC diagnosed with bone metastases seen at our institution was also included. Results. A total of 616 bone metastases sites in 317 patients were identified in 14 case series. Ten patients were identified in our institutional case series. The most common sites of metastases are spine (34.6%), pelvis (25.5%), sternum and ribs (18.3%), extremities (10.2%), shoulder girdle (5.4%), and craniomaxillofacial (5.4%). Conclusion. The axial skeleton is the primary target of bone metastases in DTC. The relative distribution of bone metastases and red marrow content follow a similar rank. (C) 2017 Wiley Periodicals, Inc.