Internal hemipelvectomy for solitary pelvic thyroid cancer metastases

Radioactive iodine (RAI) therapy remains a primary treatment modality for metastatic thyroid carcinoma, but poor tumor uptake of the agent can limit its usefulness. While offering effective palliation, radiation therapy is not curative, and chemotherapy is even less useful. Surgical resection occasionally remains the only hope of offering a long-term cure in the case of isolated metastases.

We describe 3 cases of thyroid cancer metastatic to the pelvic girdle that were unresponsive to RAI and other nonoperative therapies, which presented over a 15-year time period. The pelvic disease was the only site of active disease in all cases, and all 3 patients were suffering considerable pain. All 3 patients underwent internal hemipelvectomy with reconstruction in 2 cases using a pelvic bone allograft.

All 3 experienced symptomatic relief and early mobilization. While the infection rate was 100%, these all responded completely to operative debridement, irrigation, and antibiotics. One patient, found postoperatively to have a positive surgical margin, developed a local recurrence at 4 months and died. A second patient developed a local recurrence at 11 months and died. The third patient underwent a revision of her hip arthroplasty because of acetabular loosening after a fall 21 months postoperatively. She is alive, disease-free, and ambulatory with the aid of a cane 32 months after the original procedure.

We propose this surgical procedure in selected patients with metastatic pelvic thyroid cancer. It provides symptomatic relief with a chance for prolonged disease-free survival some patients.