Benign cystic mesothelioma: false-positive iodine accumulation in a patient with oncocytic follicular thyroid carcinoma

Our plain-English summary of Benign cystic mesothelioma: false-positive iodine accumulation in a patient with oncocytic follicular thyroid carcinoma, by M. Meyer, Y. Godbert, I. Soubeyran, et al (Clinical Nuclear Medicine, 2014).

The study

• Authors: M. Meyer, Y. Godbert, I. Soubeyran, A.L. Cazeau, F. Bonichon
• Journal: Clinical Nuclear Medicine
• Published: 2014;39(9):e395-7
• Type of article: Case report
• Cited by: 2 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Whole-body (131I) scintigraphy (WBS) is used to detect residual or metastatic tissue during treatment of differentiated thyroid carcinoma in combination with thyroglobulin (Tg) and ultrasonography of the neck. It is a highly sensitive method, but there is a high rate of false positives. We report the case of a 52-year-old woman with false-positive iodine accumulation in a benign cystic mesothelioma discovered during treatment for a oncocytic follicular thyroid carcinoma (stage pT2 pNx Mx). This lesion was detected by WBS and confirmed by surgery and histopathologic analysis.

In plain English

This was a case report, written in a short image-based format, by doctors in the nuclear medicine and pathology departments of Institut Bergonié in Bordeaux, France. It described a 52-year-old woman with oncocytic follicular thyroid carcinoma, a type of thyroid cancer, who was treated with radioactive iodine (iodine-131). A whole-body scan afterwards showed a spot of iodine uptake in the right side of her abdomen. A further scan (SPECT/CT) found a 16 by 8 mm nodule near the liver. This raised the possibility that the cancer had spread, but her thyroid cancer blood markers were negative, so the doctors monitored the nodule. A CT scan at 4 months showed it was stable. Surgical exploration by coelioscopy (keyhole surgery) was done for diagnosis and treatment. Tissue analysis showed a benign cystic mesothelioma, lined by mesothelial cells without atypia. The authors wrote that iodine uptake in this kind of lesion is extremely rare. They knew of only one earlier case. The authors concluded that better awareness of false-positive radioiodine uptake may avoid unnecessary surgery. The article did not mention asbestos. It stated that the cause of benign cystic mesothelioma is currently unknown.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: case report (single patient, 'Interesting Image' article)
• Who was studied: One 52-year-old woman with a 2.2 cm oncocytic follicular thyroid carcinoma of the right thyroid lobe (stage pT2 pNx Mx), reported by authors from Institut Bergonié, Bordeaux, France
• Exposure: No asbestos exposure is mentioned. The exposure described is radioiodine treatment (3.7 GBq iodine-131) after thyroid hormone withdrawal, followed by whole-body iodine-131 scanning
• Main results:
  • The whole-body iodine-131 scan showed focal iodine uptake in the right abdominal region
  • SPECT/CT identified a perihepatic tissue nodule (16 by 8 mm) with radioiodine uptake
  • Thyroid tumor markers were negative: thyroglobulin was less than 0.2 ng/mL and anti-thyroglobulin antibodies were normal
  • A contrast-enhanced CT scan at 4 months showed the lesion was stable
  • After surgical exploration by coelioscopy, tissue analysis showed a benign cystic mesothelioma with a multilocular cyst, lined by flattened mesothelial cells without atypia
  • The authors stated that radioiodine uptake in a benign cystic mesothelioma is extremely rare, with only one previously described case known to them
• The authors' conclusion: The authors concluded that better knowledge of the possibility of false-positive radioiodine uptake may avoid unnecessary surgery. They suggested the uptake might be explained by passive exchange of electrolytes and water between the cyst and the surrounding area.

Topics

Medical terms in this study, explained in our Lexicon: Mesothelioma, Carcinoma.

Related studies

• Giant benign cystic peritoneal mesothelioma: US, CT, and MRI findings — A. Ozgen, D. Akata, et al. (1998)
• Benign cystic mesothelioma of the peritoneum in a child-case report and review of the literature — V.C. Shakya, C.S. Agrawal, et al. (2011)
• Pediatric Benign Cystic Peritoneal Mesothelioma — J. Durell, H. Dagash, et al. (2016)
• Benign cystic mesothelioma: a diagnostic dilemma — T.S. Usha Kiran, A. Agboola, et al. (2002)
• Anaplastic thyroid carcinoma mimicking a malignant pleural mesothelioma: Clues for diagnosis — T. Capron, S. Giusiano, et al. (2019)
• Peritoneal benign cystic mesothelioma: a case report and review of the literature — S. van Ruth, M.W. Bronkhorst, et al. (2002)

Browse more research in Clinical Nuclear Medicine, or return to medical research.