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I131 Accumulation in Hydrocele in the Setting of Metastatic Papillary Carcinoma Thyroid
Address for correspondence: Dr. Vishnukumar Rajaraman, Department of Nuclear Medicine, Jawaharlal Institute of Post Graduate Medical Education and Research, Puducherry, India. E-mail: viar793@gmail.com
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Received: ,
Accepted: ,
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This article was originally published by Wolters Kluwer - Medknow and was migrated to Scientific Scholar after the change of Publisher.
Abstract
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.
Keywords
Iodine scan
papillary carcinoma thyroid
radioiodine uptake
scrotal hydrocele
A 70-year-old malewas diagnosed with a classical variant of papillary thyroid carcinoma with bilateral lung and multiple skeletal metastases. He was treated with 200 mCi of131I. Posttherapy scan [Figure 1a and b] done 5 days after the therapy showed intense tracer uptake in the thyroid bed, left clavicle region, and bilateral chest. A moderate degree of diffuse uptake was noted in the scrotal region. It was initially overlooked as urine contamination. After eliciting the history of hydrocele, a regional single photon emission computed tomography/computed tomography (SPECT/CT) was acquired to solve the suspicion. SPECT/ CT [Figure 1c and d] of the scrotal region showed tracer accumulation in the scrotal hydrocele.
- 131| whole body scan images (a and b) in the anterior and posterior view show tracer accumulation in the scrotal region (arrow). Corresponding single-photon emission computed tomography/computed tomography images in the axial section (c and d) show tracer accumulation in hydrocele
The mechanism of iodine uptake is mediated by the sodium-iodide symporter (NIS).[1] It is mainly expressed in the thyroid, salivary glands, gastric mucosa, lactating mammary gland, lacrimal glands, choroid plexus, ciliary bodies, skin, placenta, and thymus. Lower levels of NIS expression are seen in the prostate, ovaries, adrenal glands, and lungs.[23] False-positive findings in131I scan can be classified under functional uptake secondary to NIS expression, radioiodine retention, nonthyroid neoplasm, inflammatory, or infectious uptake and contamination. SPECT/CT was helpful to identify these unusual131I concentrations.[4] Non-NIS-dependent131I retention was reported in sialolithiasis, nasolacrimal duct cyst, Zenker's diverticulum, hiatal hernia, urinary tract diverticulum, and pathological serous collections in the bronchogenic cyst, ovarian cyst, hepatic cyst, thymic cyst, pleuro-pericardial cyst, and pericardial cavity. It can be due to passive diffusion and slow clearance from the serous cavities.[5678910] 131I concentration in the scrotal hydrocele was also be attributed to the same mechanism of passive diffusion.[9] In our case, clinical history and examination elicited scrotal hydrocele. Urine contamination was ruled out, and finally, the SPECT/CT confirmed the site of uptake.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Nil.
Conflicts of interest
There are no conflicts of interest.
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