Endocrine Abstracts

Background: UPEA for LRR in PTC was introduced in 1993 (JCEM 96:2717, 2011). It is not appreciated that such non-invasive ablations can often be repeated over decades (Surgery 154:1448, 2013). Skin metastases (SM) from thyroid carcinoma are typically associated with disseminated disease; average survival after SM diagnosis is 19 months (JAAD 36:531, 1997). Our case provides insights into managing LRR and SM in LRPTC.

Clinical case: In 2004, an open biopsy of a lateral neck mass in a 48-year old man revealed neck nodal metastasis (NNM) due to PTC. He had a near-total thyroidectomy and node dissection, confirming a right lobar 8 mm primary and two ipsilateral NNM; MACIS score was 4.08 and pTNM (8^th edition) stage I. During 2004, he received two doses of ¹³¹I for neck uptake (cumulative dose 12,506 MBq). In 2007, he underwent right multi-compartmental dissection for NNM. In 2008, serum thyroglobulin on T4-suppression was 4.8 ng/ml and US-guided biopsy confirmed a right level III NNM. He was referred to our institution for consideration of UPEA. During his initial evaluation, two sites of LRR were treated with UPEA and subsequently disappeared. During 2010–16, he developed another six NNM, also treated with UPEA, resulting in disappearance of all ablated lesions. In 2016, an SM in right neck was removed by dermatologic surgery. Following this, two further SM were excised with negative margins, one after Mohs surgery. He is now disease-free at 14.4 postoperative years.

Conclusions: Despite three neck surgeries and 12,506 MBq of ¹³¹I, this man with LRPTC, during postoperative years 4–14, developed eight separate sites of LRR and three sites of SM. All eleven sites were treated with minimally invasive outpatient procedures. In contrast to earlier reports, this patient is likely to survive long beyond his present 14 postoperative years.