Pulmonary sequestration: A 131I whole body scintigraphy false-positive result

A 35-year-old woman affected by a well-differentiated papillary thyroid carcinoma was referred to our hospital to perform a ¹³¹Iodine ( ¹³¹I) whole body scintigraphy for restaging purpose. The patient had been previously treated with total thyroidectomy and three subsequent doses of ¹³¹I for the ablation of a remnant jugular tissue and a suspected metastatic focus at the superior left hemi-thorax. In spite of the previous treatments with ¹³¹I, planar and tomographic images showed the persistence of an area of increased uptake at the superior left hemi-thorax. This finding prompted the surgical resection of the lesion. Histological examination of the surgical specimen showed the presence of a pulmonary tissue consistent with pulmonary sequestration. Even though rare, pulmonary sequestration should be included in the potential causes of false-positive results of radioiodine scans.