Abstract
Introduction:
The coexistence of autonomously functioning thyroid nodules (AFTNs) and Graves’ disease is referred to as Marine-Lenhart Syndrome (MLS). Estimated to occur in 0.8–4.1% of patients with Graves’.1–4
MLS and AFTNs are diagnosed using a combination of.
Radioiodine ablation (I-131) and surgery are considered definitive therapies 4 but carry risk of iatrogenic hypothyroidism. A recent prospective 2-year study evaluating the use of radiofrequency ablation (RFA) for small toxic goiters and Graves’ disease demonstrated excellent efficacy 6 The safety and efficacy of RFA for AFTNs is well-established. 7
We describe the first reported case of MLS successfully treated with RFA.
Case Description:
A 67-year-old Caucasian female with palpitations, nervousness, and shakiness. Examination revealed.
Irregular, firm goiter
Left-sided thyroid nodule
Lid lag, lid retraction
Mild exophthalmos
Laboratory Findings.
TSH: 0.01 IU/L (normal: 0.5–4.7 IU/mL) – suppressed
Free T4: 2.7 μg/dL (normal: 0.8–1.7 μg/dL) – elevated
Ultrasound.
Showed a 1.4 cc left nodule in the setting of a hyperemic gland
Radioactive Iodine Uptake and I-123 Scan
Twenty-four-hour uptake: 32.7% Homogeneous uptake in the gland with focal increased uptake in the left-sided nodule
Findings consistent with (MLS).
TSI: 4.9 IU/L (reference < 0.54 IU/L)
TRAb: 6.8 IU/L (reference 0.0–1.7 IU/L)
Methimazole poorly tolerated
I-131 versus surgery was offered but declined
Patient opted for RFA
Procedure:
pericapsular local anesthesia (2% lidocaine) An 18-gauge internally cooled electrode (Cambridge Interventional, Burlington, MA) used with a 0.7 cm active Critical structures identified and avoided Vocal cord mobility monitored via ultrasound Moving-shot technique used Ablation of left toxic nodule followed by treating the surrounding thyroid The procedure was repeated on the right lobe, 20 watts power applied Ablation time: 14 minutes Vocal cords were re-evaluated post-procedure and found to be mobile Patient advised to discontinue methimazole post-procedure
Results:
Three months post-RFA Complete resolution of hyperthyroid symptoms TSH: 3.0 μIU/mL (normal) Six months post-RFA.
TSH: 3.3 μIU/mL Free T4: 1.1 ng/mL Left AFTN: 0.2 cc (85.7% volume reduction) Left lobe volume: 2.5 cc (37.5% volume reduction) Right lobe volume: 1.7 cc (51.4% volume reduction)
One year post RFA.
TSH: 5 uIU/mL.
Free T4: 1.2 ng/mL.
TRAB titer negative.
Discussion:
MLS is a unique form of thyrotoxicosis with no clearly established treatment protocol. Patients are typically managed with I-131 or surgery, which carries the risk of permanent hypothyroidism.
This case represents the first reported instance of successful RFA treatment in a patient with MLS.
RFA is already recognized as a safe and effective option for AFTN 7 and is showing promise as a treatment for selected cases of Graves’ disease 6 This case highlights the potential role of RFA in MLS, While Fung et al.6 didn’t follow TRAB levels, in this patient titer Normalization might suggest spontaneous remission, or the possibility that RFA may normalize TRAb levels by reducing the antigenic load and altering the inflammatory microenvironment.
Authors would like to thank Mr. Anuj Kumar for his help.
Author(s) have received and archived patient consent for video recording/publication in advance of the video recording of the procedure.
Authors affirm absence of COI/no financial disclosures to report.
Running Time: 7 minutes and 7 seconds.
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