Vasconcellos, Adam1; Rosen, David1
1 Department of Otolaryngology – Head and Neck Surgery, Thomas Jefferson University Hospital, Philadelphia, PA, USA
Background/Purpose: Recently, follicular variant of papillary thyroid cancer (FVPTC) encapsulated without invasion has been reclassified as noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP). FVPTC with capsule-only (no vascular) invasion similarly portends an excellent disease-free survival post-thyroidectomy. We present a rare case of capsule-only invasive FVPTC presenting with multiple spinal metastases after thyroidectomy.
Methods/Results: A 55 year-old female presented with a left neck mass. Thyroid ultrasound confirmed a 4.4 centimeter (cm) left lower pole nodule, as well as a 0.7cm right superior pole nodule. Fine needle aspiration (FNA) biopsy of the larger nodule revealed follicular neoplasm. Per patient preference, total thyroidectomy was performed, with pathology of both nodules revealing encapsulated FVPTC, with focal capsular invasion of the larger nodule. No extrathyroidal extension or central neck lymphadenopathy was noted. 2.5 years later, she presented with posterior cervical discomfort and lower extremity weakness. Imaging revealed a T1 lesion causing spinal canal compromise. She underwent resection, and pathology analysis confirmed metastatic FVPTC. She received radioactive iodine and external beam radiation, and subsequently received further radiation to treat an isolated L3 site of metastasis one year later.
Discussion & Conclusion: FVPTC with capsular-only invasion is designated as minimally invasive and low-risk.1 Multiple retrospective studies have illustrated -free survival rates of 97-100% at 3-10 years for capsule-only invasive FVPTC after thyroidectomy.2-3 Especially given the recent change in designation for NIFTP, our case suggests a need for hypervigilance in post-thyroidectomy monitoring for encapsulated FVPTC with any demonstrated invasion.
- Haugen BR, Alexander EK, Bible KC, Doherty GM, Mandel SJ, Nikiforov YE, et al. 2015 American Thyroid Association Management Guidelines for Adult Patients with Thyroid Nodules and Differentiated Thyroid Cancer: The American Thyroid Association Guidelines Task Force on Thyroid Nodules and Differentiated Thyroid Cancer. Thyroid [Internet]. 2016;26(1):1–133. Available from: https://online.liebertpub.com/doi/10.1089/thy.2015.0020
- O’Neill CJ, Vaughan L, Learoyd DL, Sidhu SB, Delbridge LW, Sywak MS. Management of follicular thyroid carcinoma should be individualised based on degree of capsular and vascular invasion. Eur J Surg Oncol [Internet]. 2011;37(2):181–5. Available from: https://dx.doi.org/10.1016/j.ejso.2010.11.005
- van Heerden JA, Hay ID, Goellner JR, Salomao D, Ebersold JR, Bergstralh EJ, et al. Follicular thyroid carcinoma with capsular invasion alone: a nonthreatening malignancy. Surgery [Internet]. 1992 Dec;112(6):1130-6-8. Available from: https://www.ncbi.nlm.nih.gov/pubmed/1455315