Nucl Med Mol Imaging.  2018 Oct;52(5):394-397. 10.1007/s13139-018-0536-7.

Langerhans' Cell Histiocytosis Masquerading as Metastatic Papillary Thyroid Cancer on F-18 FDG PET/CT: Diagnostic Dilemma Solved by PET/CT-Guided Biopsy

• Malik D
• Kumar R
• Mittal BR
• Parkash G
• Bal A
• Bhattacharya A

• KMID: 2422803
• DOI: http://doi.org/10.1007/s13139-018-0536-7

Abstract

We present a case of papillary thyroid cancer (post-thyroidectomy status) on regular treatment with suppressive Levothyroxine therapy. On follow-up at 6 months after radioactive iodine ablation for remnant thyroid tissue, her thyroglobulin, and anti-thyroglobulin levels were 0.06 ng/ml and 670 IU/ml, respectively. Low-dose whole-body I-131 scan was negative. To look for the cause of isolated increased anti-thyroglobulin level, a whole-body ¹â¸F-FDG PET/CT was done which revealed multiple FDG-avid lytic skeletal lesions suggestive of metastases. For confirmation of diagnosis, ¹â¸F-FDG PET/CT-guided metabolic biopsy was done, which revealed Langerhans' cell histiocytosis on histopathological examination.

Keyword

Papillary thyroid cancer; Langerhans' cell histiocytosis; Anti-thyroglobulin level; ¹⁸F-FDG PET/CT; PET/CT-guided biopsy

MeSH Terms

Biopsy*
Diagnosis
Follow-Up Studies
Histiocytosis*
Iodine
Neoplasm Metastasis
Positron-Emission Tomography and Computed Tomography*
Thyroglobulin
Thyroid Gland*
Thyroid Neoplasms*
Thyroxine
Iodine
Thyroglobulin
Thyroxine