RESUMEN
INTRODUCTION: Medullary carcinoma accounts for 1-2% of all thyroid malignancies. 13-20% of patients present with distant metastasis, with 45% of the cases affecting the liver. CLINICAL CASE: A 50-year-old woman, diagnosed with medullary thyroid carcinoma, was treated with total thyroidectomy and a modified neck dissection in 1999. Two lymph node recurrences in the neck were treated with surgical resection; during surveillance, she developed elevated calcitonin levels, the recurrence site was identified with 18F-DOPA PET/CT in the liver. Metabolic activity was not associated with a visible lesion in CT, MRI nor ultrasound. Radioguided surgery with 18F-DOPA allowed an anatomic resection of segments IVb and V. DISCUSSION: In patients with medullary carcinoma and elevated calcitonin during surveillance, 18F-DOPA PET/CT is an option to evaluate the site of recurrence. Radioguided resection was feasible in this patient, whose hepatic recurrence was not visible with any other imaging method. CONCLUSION: Radioguided hepatic resection with 18F-DOPA in metastatic medullary thyroid carcinoma is feasible when the recurrence site is not anatomically identified by any other imaging studies.