Faisal Dalvi

Background: Marine-Lenhart syndrome (MLS) is a rare thyroid disorder characterized by the coexistence of Graves' disease (GD) with autonomously functioning thyroid nodules. This overlap presents diagnostic and therapeutic challenges due to the dual hyperthyroid mechanisms involved. Case Presentation: A 32-year-old female presented with weight loss, palpitations, heat intolerance, and nervousness. Physical examination revealed a slightly enlarged thyroid without palpable nodules. Laboratory results confirmed hyperthyroidism with suppressed thyroid-stimulating hormone (TSH) and elevated free thyroxine (FT4) and free tri-iodothyronine (FT3). Thyroid scintigraphy identified a hyperfunctioning nodule in the right lobe, and ultrasonography confirmed a 2.5 × 2.0 cm hypoechoic nodule with increased vascularity. Fine needle aspiration cytology (FNAC) categorized the lesion as Bethesda category 2 (benign). Elevated TSH receptor antibody (TRAb) levels confirmed concurrent GD. The patient was diagnosed with MLS and initiated on carbimazole, achieving biochemical euthyroidism within three months. Given her personal circumstances, radioiodine therapy was deferred. Discussion: MLS remains underrecognized due to its variable presentation and resemblance to Plummer’s disease and classical GD. Accurate differentiation is critical, as the management strategy differs from isolated GD or toxic nodular goiter. While antithyroid drugs provide symptomatic control, definitive treatment often requires radioiodine therapy or surgery. The presence of thyroid nodules in GD also raises concerns about potential malignancy, necessitating close monitoring. Conclusion: This case highlights the importance of considering MLS in patients with Graves’ disease and coexisting thyroid nodules. A tailored approach integrating clinical, biochemical, and imaging findings is essential for optimal management.

Autonomous functioning thyroid nodules (AFTNs) are characterized by hyperfunctioning nodules within an otherwise normal thyroid gland, predominantly affecting adults and rarely observed in pediatric populations, especially pre-pubertal children. The management of AFTNs in children is complex due to their rarity and the potential long-term consequences of treatment. While radioiodine ablation (RAIA) is a common treatment in adults, its application in children is limited by concerns about growth, fertility, and cancer risks. Alternative treatments include conservative management with antithyroid drugs or observation, and surgical options like hemithyroidectomy. This manuscript presents a case report of a nine-year-old girl with AFTN-induced thyrotoxicosis, outlining the diagnostic and therapeutic challenges associated with this condition in children. The case underscores the need for individualized treatment strategies in pediatric AFTNs, balancing the benefits and risks of various modalities. The rarity of AFTNs in children, combined with the paucity of standardized guidelines, highlights the necessity for further research to optimize management outcomes in this population.