I¹³¹ Accumulation in hydrocele in the setting of metastatic papillary carcinoma thyroid

¹³¹I is widely used for the treatment of goiter and residual and metastatic thyroid cancer. Uptake of ¹³¹I is mainly due to the expression of sodium-iodide symporter in the target tissues. Incidental third space accumulation in the pleural and pericardial cavity can be encountered due to passive diffusion of tracer into these cavities. We present an interesting finding of ¹³¹I accumulation in the scrotal hydrocele in a 70-year-old patient with a metastatic classical variant of papillary thyroid carcinoma, who was treated with 200 m Ci of ¹³¹I. (author)