Learning objectives
Describe the usual thyroidectomy neck aspect at cross-sectional imaging.
Discuss recurrence mimics in the surgical bed.
Review anatomic characteristics and surgical landmarks related to recurrence patterns.
Emphasize structural reports with central and lateral compartment scrutiny.
Background
Differentiated thyroid cancer (DTC) accounts for more than 90% of thyroid cancer.
Surgery remains the primary treatment modality.
Small thyroid remnants are common after surgery and small tumor nests can remain in less extensive surgeries.
CT and MRI exams are not routinely used but may be helpful in selected cases. Neck studies are also obtained in these patients for unrelated reasons.
Knowledge of the usual post-operative aspect, benign mimics, and patterns of recurrence is important.
Findings and procedure details
1- Describe the usual thyroidectomy neck aspect
A) Types of surgery
Total thyroidectomy: larger than 4 cm nodule, extrathyroidal extension, or metastatic disease.
Hemithyroidectomy: less than 1 cm nodule, no extrathyroidal extension or metastatic disease.
B) Surgical Bed
Preservation of strap muscles and sternocleidomastoid muscle.
Complete absence of glandular tissue.
Fibrofatty connective tissue fills the surgical cavity with loss or haziness of paratracheal fat planes.[Fig 1]
Slight loss of volume in the central compartment.
C) Cervical dissection
Central dissection or removal of level VI lymph...
Conclusion
Assessment of the post-operative neck can be tricky. Ultrasound evaluation is established as the first-line exam. However, radiologists are often confronted with post-thyroidectomy neck CT and MRI scans.
Familiarity with the expected anatomic changes can avoid misinterpretation.
Knowing the usual recurrence locations is also of help.
A thorough and clear report of findings is better achieved with a structural report template
Personal information and conflict of interest
A. s. d. Costacurta:
Nothing to disclose
References
Kumbhar SS, O’ Malley RB, Robinson TJ. Why Thyroid Surgeons are Frustrated with Radiologists: Lessons Learned from pre and Postoperative US.Radiographics 2016: 36:2141-2153. DOI:10.1148/rg.2016150250
Zeuren R, Biagini A, Grewal R et al. RAI Thyroid Bed Uptake after Total Thyroidectomy: a Novel SPECT-CT Anatomic Classification System. Laryngoscope 2015:125: 2417-2424. DOI:10.1002/lary.25295
Chua WY, Langer JE, Jones LP et al. Surveillance Neck Sonography After Thyroidectomy for Papillary Thyroid Carcinoma: Pitfalls in the Diagnosis of Locally Recurrent and Metastatic Disease. Journal of Ultrasound in Medicine 2017; 36.Issue 7. DOI:10.7863/ultra.16.08086...