Citations

Background: Pretibial dermopathy (PTD) is a rare, disfiguring manifestation of Graves’ disease. The shared pathophysiology with thyroid eye disease (TED), centered on fibroblast activation via a thyroid-stimulating hormone receptor and insulin-like growth factor-1 receptor (IGF-1R) complex, provides a strong rationale for using the IGF-1R inhibitor, teprotumumab. Methods: We present a case series of five patients with severe PTD and concomitant TED who were treated with teprotumumab. A review of reported cases in the literature was also conducted. Results: All patients experienced significant clinical improvement, including regression of skin thickening as well as enhanced functional capacity. Side effects included mild hearing loss, muscle cramps, and fatigue. One patient experienced a severe gastrointestinal event requiring treatment discontinuation, while those experiencing a recurrence of PTD, responded to a second course of therapy. Conclusions: Teprotumumab showed promising efficacy in the treatment of PTD. Further studies are needed to confirm its durability and safety.

Abstract Disclosure: D. Hamadi: None. A. Algeciras-Schimnich: None. M. Stan: None. Background: Thyroid hormone-binding proteins (TBPs)—thyroxine-binding globulin (TBG), transthyretin, and albumin—play a critical role in transporting thyroid hormones in the bloodstream. Rare genetic alterations in these proteins can lead to discordant thyroid function test (TFT) results, potentially mimicking thyroid dysfunction despite a clinically euthyroid state. This study retrospectively evaluates the clinical scenarios that warrant TBP testing. Methods: Data was extracted from the electronic medical record (EMR) at the Mayo Clinic in Rochester, MN. The study included patients who had Thyroid-binding protein electrophoresis (TBPE) ordered between 2016 to 2023. Results: A total of 138 patients were included (53% female; median age: 58 years) of which 42% had TBP abnormalities. TBP testing was frequently ordered by endocrinology (33%), followed by cardiology (9%) and family medicine (7%). Discrepancies between thyroid-stimulating hormone (TSH) and total T4 (TT4) were identified in 41 patients of which 75% had abnormal TBP. Among these, eleven were diagnosed with familial dysalbuminemic hyperthyroxinemia (FDH), including one with a known family history. Additionally, five patients were diagnosed with thyroid hormone resistance—one of whom had previously been misdiagnosed with Graves’ disease. Three patients were found to have TSH-secreting tumors, and three were receiving infusion therapy with patisiran with resulting TBP abnormalities. The remaining cases involved binding protein abnormalities, most commonly presenting as elevated TBG. Conclusion: This study identified varied clinical utilization for TBP testing, from very appropriate indications to cases of doubtful clinical utility. TBP abnormalities were clinically meaningful in 22% of cases, supporting the utility of testing in select scenarios. Specifically, TBP testing should be reserved for situations with a clear discrepancy between clinical presentation and TFT results—particularly discordant TSH and total T4 levels. In such contexts, TBP assessment is valuable in preventing misdiagnoses and avoiding unnecessary treatments, especially since individuals with TBP mutations are typically clinically euthyroid. Presentation: Sunday, July 13, 2025

Abstract Imaging-guided percutaneous core needle biopsy is currently the most common technique for the investigation of potentially malignant bone lesions. It allows precise needle placement and better visual guidance, leading to improved diagnostic accuracy. Needle tract seeding (NTS) is a rare complication of biopsies in general, and its true incidence remains unknown. This study aimed to assess the risk of NTS in patients with thyroid cancer who underwent bone biopsy. For our cohort, we extracted data from the electronic medical record at the Mayo Clinic in Rochester (Minnesota, USA). Inclusion criteria included patients with a history of thyroid cancer who underwent biopsy for bone metastasis between 1/1/2014 and 10/1/2023. We identified a cohort of 20 patients that fit our inclusion criteria. Of these 20 patients, 2 patients developed NTS after CT-guided bone biopsy. Cases of seeding had a larger tumor size, a more aggressive histopathological presentation, a significantly shorter duration between cancer diagnosis and bone metastasis, and underwent more tumor manipulation procedures, such as biopsy and radiofrequency ablation, in contrast to those without seeding. In conclusion, our study identified NTS to have an incidence of 10% after biopsies of bone metastasis related to thyroid carcinoma. These are likely the result of an interplay of risk factors, including tumor biology, penetrated tissues and procedural technical details. Further studies with larger sample sizes are needed to confirm our findings and identify strategies to mitigate NTS.

Abstract Background Autonomously functioning thyroid nodules (AFTNs) constitute 5% to 7% of thyroid nodules and represent the second most common cause of hyperthyroidism following Graves’ disease. Currently, radioactive iodine (RAI) and surgery are the standard treatment options, and both incur a risk of postprocedural hypothyroidism and other surgery and radiation-related complications. Methods This work aimed at assessing the efficacy of radiofrequency ablation (RFA) as an alternative treatment option for resolving hyperthyroidism and the nodule volume rate reduction (VRR) and its associated adverse events. Results A total of 22 patients underwent RFA for a solitary AFTN. Seventy-two percent (n = 16) had subclinical hyperthyroidism, 9% (n = 2) had overt hyperthyroidism, and 18% (n = 4) were biochemically euthyroid on antithyroid medication. Average pretreatment TSH was 0.41 mIU/L (SD = 0.98) and free T4 1.29 ng/dL (SD = 0.33). Following a single RFA session, hyperthyroidism resolved in 90.9% (n = 20) and average VRR (61.13%) was achieved within 3 to 6 months following the ablation. Except for 1 nodule, none of the nodules grew during the follow-up period (16.5 months). Two patients (9%) developed transient tachycardia requiring short-term beta-blocker therapy, and 2 developed mild hypothyroidism requiring levothyroxine therapy. Two patients developed recurrent hyperthyroidism and elected to undergo lobectomy and repeat RFA respectively. No serious adverse effects were noted in this cohort. Conclusion RAI and/or surgery represent the standard of care for toxic adenomas, but RFA shows excellent efficacy and safety profile. Therefore, at centers with RFA expertise, it should be considered an alternative treatment strategy, avoiding radiation and surgery-related complications.

Abstract Disclosure: C.A. Conover: None. L.K. Bale: None. D. Hamadi: None. M. Stan: ; Tourmaline, Genentech, Third Rock Ventures, ArgenX, Septerna, OrthoDi. ; Horizon, Immunovant, Lassen, Sling. Background: Proptosis in Thyroid Eye Disease (TED) can result in facial disfigurement and visual dysfunction. Studies revealed an interaction between thyroid-stimulating hormone receptor (TSHR) and insulin-like growth factor-I receptor (IGF-IR) that is essential in promoting TED pathogenesis. Treatment with Insulin-like growth factor I receptor (IGF-IR) inhibitors has been shown to be effective in reducing proptosis but with side effects. PAPP-A is metalloprotease that can increase pericellular IGF bioavailability through specific cleavage of inhibitory IGF binding proteins, in particular IGFBP-4. We propose that inhibition of IGF-IR indirectly and more selectively with PAPP-A inhibitory antibodies attenuates IGF-IR signaling in TED with fewer side effects. Methods: Informed consent was obtained from TED patients undergoing surgery in Mayo Clinic operating suites in Rochester, MN. Retro-orbital tissue was collected from 19 TED patients and 2 control subjects for fibroblast isolation and culture and was performed in a sterile tissue culture facility. TED and control fibroblasts were treated with pro-inflammatory cytokines, and flow separation of CD34- and CD34+ orbital fibroblasts was done, the latter representing infiltrating fibrocytes into the orbit in TED. Main outcome measured were PAPP-A expression and proteolytic activity, IGF-I stimulation of phosphatidylinositol 3 kinase/Akt pathway and inhibition by immuno-neutralizing antibodies against PAPP-A, CD34+ status and associated PAPP-A and IGF-IR expression. Results: Primary cultured cells showed that PAPP-A is expressed in orbital fibroblasts from TED patients but not in control subject fibroblasts and were markedly increased by pro-inflammatory cytokines stimulation. IGF-IR expression was not affected by cytokine treatment. Inhibition of PAPP-A’s proteolytic activity suppressed IGF-IR activation in orbital fibroblasts from TED patients. CD34+ orbital fibroblasts represent 80% of cells in culture from TED patients, and approximately 70% of these cells were accountable for PAPP-A and IGF-IR expression. Conclusion: These results support a role for PAPP-A in TED pathogenesis and indicate the potential for novel therapeutic targeting of the IGF axis. Presentation: 6/2/2024