Category: Thyroid

Monitor: 13


Thursday, Apr 25
12:30 PM – 1:00 PM

Objective : To report a case in which an ultrasound (US) guided fine needle aspiration (FNA) caused an intrathyroidal pseudoaneurysm and to demonstrate the utility of making the correct diagnosis using doppler US.

Methods : A 68-year-old female with a history of multinodular goiter presented for an FNA of bilateral thyroid nodules. The patient reported an US guided FNA of her thyroid nodules six years prior which was benign. The patient was clinically and biochemically euthyroid and had no compressive symptoms. A bedside thyroid US was performed prior to the FNA procedure.

Results : Bedside US revealed multiple thyroid nodules bilaterally with an intrathyroidal pseudoaneurysm within the dominant right sided thyroid nodule measuring 4.1 x 2.0 x 2.5 cm. Color doppler revealed bidirectional blood flow within the aneurysm (Ying-yang sign). As a result, FNA of that area was avoided. Review of an outpatient thyroid US from five months prior revealed that the pseudoaneurysm was present but not reported. Given the location of the pseudoaneurysm and the knowledge of an US guided FNA six years prior, it is likely that the pseudoaneurysm is a direct result of the US guided FNA at that time.

Discussion : A true aneurysm is a weakened area within a blood vessel wall, affecting all three layers of the vessel, resulting in a ballooning of the wall.  A pseudoaneurysm occurs from an injury to a blood vessel wall resulting in a blood collection contained in the peri-vascular tissue. Pseudoaneurysms can occur as a result of trauma, infection, vasculitis or iatrogenic puncture. Most pseudoaneurysms resolve spontaneously; however, pseudoaneurysms with higher blood flow, larger than 3 cm in diameter, or are rapidly expanding are less likely to resolve without intervention. Iatrogenic intrathyroidal pseudoaneurysms resulting from US guided FNA are rare and can theoretically lead to complications including dysphagia, airway compromise and hemorrhage if there is spontaneous rupture. Although there is not enough data to provide treatment guidelines for intrathyroidal pseudoaneurysms, treatment for pseudoaneurysms in general include US guided compression, surgical ligation, endovascular intervention, percutaneous thrombin injection, and radiofrequency ablation. In our case, we referred the patient for further studies and possible intervention.

Conclusion : It is important to be aware that intrathyroidal pseudoaneurysms are rare but potential complications of US guided FNAs. It is also important to identify these lesions in order to provide early intervention when necessary and to avoid procedures such as FNA if they are misidentified as thyroid nodules.


Tien-Hao Lee

New York Presbyterian Brooklyn Methodist Hospital

Internal medicine resident at New York Presbyterian Brooklyn Methodist Hospital

Russell Gibson

Radiology Attending Physician
New York Presbyterian Brooklyn Methodist Hospital - Department of Radiology

Radiology Attending Physician at New York Presbyterian Brooklyn Methodist Hospital

Judith Giunta

Endocrinology Attending Physician
New York Presbyterian Brooklyn Methodist Hospital - Department of Endocrinology, Diabetes & Metabolism

Endocrinology Attending Physician at New York Presbyterian Brooklyn Methodist Hospital