CASES OF THE WEEK – “Ectopic thyroid tissue in thyroglossal duct remnant is related to elevation of serum thyroglobulin after I-131 ablation therapy (short case)” by Dr ShekharShikare, HOD & Consultant, Nuclear Medicine & Dr Nawal Ibraheem, Consultant Endocrinology
Thyroglossal duct remnant (TGDR) is visualized in pre and post-ablative I-131 follow up whole body scan (WBS) and the correlation between the change of serum thyroglobulin (Tg) level after I-131 ablation therapy (IAT) and TGDR in differentiated thyroid cancer (DTC) patients.
Case
41 years old lady with h/o total thyroidectomy august 2018 (Histopathology differentiated papillary cancer thyroid ( T3NxMx). Post operatively Thyrogen stimulated diagnostic 131 Whole Body Scan done in September.2019
131-IODINE WHOLE BODY SCAN (166.5 MBq scan post Thyrogen injection)
It shows small residual functioning thyroidal tissue (less avid tracer uptakes).
Comparatively bigger remnant functioning thyroidal tissue (thyroglossal cyst) in midline of neck at the level of hyoid bone (little towards left)
All the abnormalities are better appreciated in SPECT-CT fused images.
Subsequently patient was treated with 29.6 mCi of RADIOACTIVE IODINE THERAPY received in Dec 2019 and post therapy whole body iodine scan showed avid tracer uptakes in residual thyroid and thyroid remnant tissues.
Post Radioactive Iodine Therapy, patient was on 100 micrograms of thyroxine tablet per day.
Dec 2020 ( on T4 medication) TSH 0.093, Thyroglobulin (Tg) ≺ 0.040 & Anti TgAB 51
Post therapy follow up scan (Feb 2021)
131-IODINE WHOLE BODY SCAN (159.1 MBq scan post Thyrogen injection)
It shows small remnant functioning thyroidal tissue in (thyroglossal cyst) in midline of neck at the level of hyoid (little more towards left).
Better appreciated in SPECT-CT fused images
Rest of the whole-body images are unremarkable.