Rare Thyroid Diseases Mimicking or Concealing Primitive Thyroid Neoplasms: A Call for a "Check and Double-Check" Clinical Mindset.

Clinical endocrinologists encounter in their practice patients with thyroid diseases on a daily basis. Still, diagnosis of rare structural thyroid disorders can be quite challenging. In some instances, they do not only impersonate but can also conceal, other conditions such as thyroid carcinomas. We describe a series of patients with structural thyroid disorders including 1) anaplastic thyroid carcinoma initially presenting with features of thyroid abscess; 2) unicentric hyaline vascular Castleman's disease of the thyroid embedded in a stroma of papillary thyroid carcinoma; and 3) primary thyroid lymphoma with a rapid and fulminant evolution. The common challenge in the diagnosis of these cases lies in both their low incidence and their complex presentation. We use the presentation of these cases to raise the attention related to their identification. We highlight the need for precision diagnosis to enable a patient-tailored management approach and improve patient outcomes.

Phase II Trial Assessing the Repeatability and Tumor Uptake of [68Ga]Ga-HER2 Single-Domain Antibody PET/CT in Patients with Breast Carcinoma.

Human epidermal growth factor receptor 2 (HER2) status is used for decision-making in breast carcinoma treatment. The status is obtained through immunohistochemistry or in situ hybridization. These two methods have the disadvantage of necessitating tissue sampling, which is prone to error due to tumor heterogeneity or interobserver variability. Whole-body imaging might be a solution to map HER2 expression throughout the body. Methods: Twenty patients with locally advanced or metastatic breast carcinoma (5 HER2-positive and 15 HER2-negative patients) were included in this phase II trial to assess the repeatability of uptake quantification and the extended safety of the [68Ga]Ga-NOTA-anti-HER2 single-domain antibody (sdAb). The tracer was injected, followed by a PET/CT scan at 90 min. Within 8 d, the procedure was repeated. Blood samples were taken for antidrug antibody (ADA) assessment and liquid biopsies. On available tissues, immunohistochemistry, in situ hybridization, and mass spectrometry were performed to determine the correlation of HER2 status with uptake values measured on PET. If relevant preexisting [18F]FDG PET/CT images were available (performed as standard of care), a comparison was made. Results: With a repeatability coefficient of 21.8%, this imaging technique was repeatable. No clear correlation between PET/CT uptake values and pathology could be established, as even patients with low levels of HER2 expression showed moderate to high uptake. Comparison with [18F]FDG PET/CT in 16 patients demonstrated that in 7 patients, [68Ga]Ga-NOTA-anti-HER2 shows interlesional heterogeneity within the same patient, and [18F]FDG uptake did not show the same heterogeneous uptake in all patients. In some patients, the extent of disease was clearer with the [68Ga]Ga-NOTA-anti-HER2-sdAb. Sixteen adverse events were reported but all without a clear relationship to the tracer. Three patients with preexisting ADAs did not show adverse reactions. No new ADAs developed. Conclusion: [68Ga]Ga-NOTA-anti-HER2-sdAb PET/CT imaging shows similar repeatability to [18F]FDG. It is safe for clinical use. There is tracer uptake in cancer lesions, even in patients previously determined to be HER2-low or -negative. The tracer shows potential in the assessment of interlesional heterogeneity of HER2 expression. In a subset of patients, [68Ga]Ga-NOTA-anti-HER2-sdAb uptake was seen in lesions with no or low [18F]FDG uptake. These findings support further clinical development of [68Ga]Ga-NOTA-anti-HER2-sdAb as a PET/CT tracer in breast cancer patients.

Treatment of a mycotic abdominal aortic aneurysm with the jailing technique.

PURPOSE: We explored an innovative technique in treating mycotic aortic aneurysms. CASE REPORT: A patient presenting with severe back pain, vague abdominal pain, weight loss and decline in general health, was diagnosed with a contained-rupture of a suprarenal mycotic aortic aneurysm, as a complication of spondylodiscitis. Since the patient's health condition was too poor to perform an open aortic repair, we choose an alternative treatment option by coiling the aneurysm with the jailing technique. CONCLUSION: We observed a good clinical outcome.