Indian Journal of Nuclear Medicine
Home | About IJNM | Search | Current Issue | Past Issues | Instructions | Ahead of Print | Online submissionLogin 
Indian Journal of Nuclear Medicine
  Editorial Board | Subscribe | Advertise | Contact
Users Online: 149 Print this page  Email this page Small font size Default font size Increase font size

 Table of Contents     
Year : 2022  |  Volume : 37  |  Issue : 1  |  Page : 101-102  

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

Department of Nuclear Medicine, Jawaharlal institute of Post Graduate Medical Education and Research, Puducherry, India

Date of Submission25-Jun-2021
Date of Decision14-Aug-2021
Date of Acceptance31-Aug-2021
Date of Web Publication25-Mar-2022

Correspondence Address:
Dr. Vishnukumar Rajaraman
Department of Nuclear Medicine, Jawaharlal Institute of Post Graduate Medical Education and Research, Puducherry
Login to access the Email id

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/ijnm.ijnm_98_21

Rights and Permissions

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

How to cite this article:
Seetharam S J, Rajaraman V, Pandit N. I131 Accumulation in hydrocele in the setting of metastatic papillary carcinoma thyroid. Indian J Nucl Med 2022;37:101-2

How to cite this URL:
Seetharam S J, Rajaraman V, Pandit N. I131 Accumulation in hydrocele in the setting of metastatic papillary carcinoma thyroid. Indian J Nucl Med [serial online] 2022 [cited 2022 Aug 18];37:101-2. Available from:

A 70-year-old male was diagnosed with a classical variant of papillary thyroid carcinoma with bilateral lung and multiple skeletal metastases. He was treated with 200 mCi of 131I. Posttherapy scan [Figure 1]a and [Figure 1]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.
Figure 1: 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

Click here to view

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.[2],[3] False-positive findings in 131I 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 unusual 131I concentrations.[4] Non-NIS-dependent 131I 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.[5],[6],[7],[8],[9],[10] 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


Conflicts of interest

There are no conflicts of interest.

   References Top

Chung JK. Sodium iodide symporter: Its role in nuclear medicine. J Nucl Med 2002;43:1188-200.  Back to cited text no. 1
Bizhanova A, Kopp P. Minireview: The sodium-iodide symporter NIS and pendrin in iodide homeostasis of the thyroid. Endocrinology 2009;150:1084-90.  Back to cited text no. 2
Carvalho DP, Ferreira AC. The importance of sodium/iodide symporter (NIS) for thyroid cancer management. Arq Bras Endocrinol Metabol 2007;51:672-82.  Back to cited text no. 3
Blum M, Tiu S, Chu M, Goel S, Friedman K. I-131 SPECT/CT elucidates cryptic findings on planar whole-body scans and can reduce needless therapy with I-131 in post-thyroidectomy thyroid cancer patients. Thyroid 2011;21:1235-47.  Back to cited text no. 4
Francese C, Schlumberger M, Travagli JP, Vera P, Caillou B, Parmentier C. Iodine 131 uptake in a pleuropericardial cyst: Case report of a false-positive radioiodine total body scan result in a patient with a thyroid cancer. Eur J Nucl Med 1991;18:779-80.  Back to cited text no. 5
Glazer DI, Brown RK, Wong KK, Savas H, Gross MD, Avram AM. SPECT/CT evaluation of unusual physiologic radioiodine biodistributions: Pearls and pitfalls in image interpretation. Radiographics 2013;33:397-418.  Back to cited text no. 6
Shapiro B, Rufini V, Jarwan A, Geatti O, Kearfott KJ, Fig LM, et al. Artifacts, anatomical and physiological variants, and unrelated diseases that might cause false-positive whole-body 131-I scans in patients with thyroid cancer. Semin Nucl Med 2000;30:115-32.  Back to cited text no. 7
Singh AK, Bodolan AA, Gilbert MP. A false positive I-131 metastatic survey caused by radioactive iodine uptake by a benign thymic cyst. Case Rep Endocrinol 2017;2017:e6469015.  Back to cited text no. 8
Greenler DP, Klein HA. The scope of false-positive iodine-131 images for thyroid carcinoma. Clin Nucl Med 1989;14:111-7.  Back to cited text no. 9
Chudgar AV, Shah JC. Pictorial review of false-positive results on radioiodine scintigrams of patients with differentiated thyroid cancer. Radiographics 2017;37:298-315.  Back to cited text no. 10


  [Figure 1]


    Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
    Access Statistics
    Email Alert *
    Add to My List *
* Registration required (free)  

  In this article
    Article Figures

 Article Access Statistics
    PDF Downloaded42    
    Comments [Add]    

Recommend this journal