Thyroid Storm Precipitated by Fine-needle Aspiration

Abstract

Thyroid storm is a life-threatening exacerbation of hyperthyroidism, marked by a sudden surge in thyroid hormone levels that can lead to multiorgan dysfunction and death. Common triggers include medication nonadherence, infections, radioiodine therapy, iodinated contrast, labor, surgery, and trauma. We report a rare case of thyroid storm precipitated by fine-needle aspiration. The patient was successfully managed medically and later underwent surgery after normalization of thyroid function. Clinicians should exercise caution when performing fine-needle aspiration in thyrotoxic patients. It should be performed only in a limited number of cases where there is clinical or ultrasound suspicion of malignancy and after thyroid function tests have normalized.

Introduction

Thyroid storm, or thyrotoxic crisis, is a rare, life-threatening condition marked by a sudden hypermetabolic state because of excessive thyroid hormone release in patients with thyrotoxicosis [1]. Thyroid storm presents with severe exacerbation of thyrotoxicosis symptoms, which include central nervous system symptoms (eg, restlessness, dehydration, extreme agitation, delirium, coma), fever, tachycardia, congestive heart failure, or gastrointestinal disturbances (eg, diarrhea, nausea, vomiting) [2]. The diagnosis of thyroid storm is based on clinical features and involves the use of clinical diagnostic criteria such as the Burch-Wartofsky point scale or Japanese Thyroid Association criteria [3]. Prompt recognition and management of thyroid storm are imperative to improve patient outcomes and reduce mortality.

Thyroid storm is associated with a significantly increased mortality rate if left untreated, and mortality can still reach as high as 10% despite appropriate medical intervention. The primary cause of death in thyroid storm is multiorgan failure. Old age, central nervous system dysfunction at admission, nonuse of antithyroid drugs and β-blockade, and the need for mechanical ventilation are factors significantly associated with increased mortality [4].

Several factors can precipitate the onset of a thyroid storm; the most common factors are irregular use/discontinuation of thyroid medicine, infection, radioiodine therapy, recent use of iodinated contrast agent, physiological stress related to labor and delivery, and trauma [3]. Although thyroid surgery and other invasive surgical procedures have been implicated as possible precipitants of thyroid storm, minor procedures such as FNA of the thyroid are rarely reported [5, 6]. Here, we report a thyroid storm triggered by a rare precipitant, the FNA of the thyroid gland.

Case Presentation

A 45-year-old female patient presented to the adult emergency unit of Tibebe Ghion Specialized Hospital with agitation, palpitations, nausea, vomiting, diaphoresis, low-grade fever, and abdominal pain that began approximately 60 minutes after FNA of the largest nodule in the right thyroid lobe. FNA was performed on patient request despite the absence of a clinical indication. She had no such symptoms before the procedure, and her vital signs were within normal limits (blood pressure: 130/80 mm Hg; heart rate: 90 beats per minute; temperature: 36.5 °C; respiratory rate: 16 breaths per minute). Ten months prior, she had been evaluated for anterior neck swelling associated with palpitations, easy fatigability, weight loss, heat intolerance, and excessive sweating and was diagnosed with a toxic multinodular goiter.

On physical examination, the patient had a 4 cm × 5 cm multinodular and asymmetric thyroid gland, which was more prominent on the right side and without retrosternal extension. Ophthalmologic and dermatologic examinations were unremarkable. The serum TSH receptor antibody level was undetectable. She was initiated on methimazole (5 mg orally twice daily) and propranolol (40 mg orally daily), which alleviated her symptoms but did not correct her thyroid function test, which was performed 2 weeks before the FNA (TSH < 0.09 µIU/mL [reference range: 0.5-4.5 mIU/L]; free T4: 12.45 pmol/L [0.97 ng/dL] [reference range: 3.0-8.0 pmol/L; 0.23-0.62 ng/dL]; and free T3: 10.28 pmol/L [6.69 pg/mL] [reference range: 3.5-7.8 pmol/L; 2.28-5.10 pg/mL]). The dose of methimazole was not adjusted because the patient did not have regular follow-up after improvement of the symptoms.

On emergency evaluation, the patient exhibited agitation and signs of respiratory distress, including tachypnea (respiratory rate of 32 breaths per minute) and hypoxemia (SpO2 of 88% on room air). She was hypertensive (blood pressure of 160/100 mm Hg) and tachycardic (pulse rate of 136 beats per minute and regular). Additionally, she presented with a low-grade fever (37.5 °C). Anterior neck examination revealed a 4 cm × 5 cm soft, nontender, asymmetric, multinodular mass in the anterior neck that was mobile on deglutition. There is no bruit on auscultation of the thyroid gland. The Pemberton sign was negative. There was no cervical lymphadenopathy. The patient appeared restless and agitated, with a fine tremor in the hands and hyperactive deep tendon reflexes graded 3/4. Cardiac, ophthalmologic, and dermatologic examinations were unremarkable.

Diagnostic Assessment

Our patient fulfilled the clinical diagnostic criteria for thyroid storm, with a score of 60 on the Burch-Wartofsky point scale, a commonly used clinical assessment. Laboratory investigations revealed the following: thyroid function test: TSH < 0.09 µIU/mL (reference range: 0.5-4.5 mIU/L); free T4: 39.33 pmol/L (3.06 ng/dL) (reference range: 3.0-8.0 pmol/L; 0.23-0.62 ng/dL); free T3: 12.28 pmol/L (7.99 pg/mL) (reference range: 3.5-7.8 pmol/L; 2.28-5.10 pg/mL); serum potassium: 3.20 mmol/L (reference range: 3.5-5.0 mEq/L or mmol/L); calcium: 7.77 mg/dL (1.94 mmol/L) (reference range: 8.5-10.5 mg/dL; 2.2-2.7 mmol/L); sodium: 142 mmol/L (reference range: 135-145 mEq/L or mmol/L); and chloride: 110.00 mmol/L (reference range: 96-110 mEq/L or mmol/L). Complete blood count, random blood sugar, liver function, and kidney function test results were within normal ranges.

Thyroid ultrasound revealed multiple bilateral thyroid nodules with cystic components, with the largest measuring 3.5 cm × 2.6 cm without calcification. There was no sign of increased blood flow in the thyroid gland. FNA cytology of the largest nodule in the right thyroid lobe suggested a benign colloid goiter with cystic degeneration.

Treatment

Following evaluation in the emergency department, the patient was promptly treated for a thyroid storm and subsequently transferred to the medical intensive care unit for close monitoring and management. She was treated with intranasal oxygen, 60 mg of propranolol orally every 4 hours, 1000 mg of propylthiouracil (PTU) loading, then 250 mg every 4 hours, 300 mg of hydrocortisone intravenous load, then 100 mg every 8 hours, Lugol iodine 10 drops orally 4 times per day started 1 hour after propylthiouracil administration, and acetaminophen 1 g orally as needed. The treatment was tapered after 48 hours as she improved. The electrolyte disturbances were also corrected after replacement.

Outcome and Follow-up

After appropriate management of the thyroid storm and optimization of her antithyroid medications, the patient was discharged in stable condition, with a follow-up appointment scheduled shortly thereafter. At 3 months’ postdischarge, her symptoms had resolved and her laboratory values had normalized. She subsequently underwent thyroid surgery, with tissue biopsy results confirming a benign colloid goiter with cystic degeneration. She is currently on levothyroxine 50 mcg orally per day and has a normal thyroid function test.

Discussion

Thyroid storm is a life-threatening syndrome caused by an exacerbation of thyrotoxicosis [3]. The diagnosis relies mainly on clinical presentation and organ involvement, as peripheral thyroid hormone levels do not reflect hyperthyroidism severity or predict progression to a thyroid storm [2]. The Burch-Wartofsky point scale is a widely used clinical tool for diagnosing a thyroid storm. It assesses various parameters, including body temperature, cardiovascular symptoms (such as tachycardia, atrial fibrillation, and heart failure), gastrointestinal dysfunction, central nervous system disturbances, and the presence of precipitating factors. A total score of ≥45 indicates a high likelihood of a thyroid storm; a score of 25 to 44 suggests an impending storm, whereas a score below 25 makes the diagnosis unlikely [7].

Thyroid storm occurs in 1% to 2% of hospital admissions for thyrotoxicosis and is associated with up to 12 times higher mortality than thyrotoxicosis without a storm [8]. Our patients were diagnosed with a thyroid storm, with a total score of 60 points. Thyroid storm often occurs following a precipitating event, such as nonadherence to antithyroid medication, infection, surgery, childbirth, trauma, or exposure to exogenous iodine or amiodarone [7].

FNA has been reported as a rare precipitating factor for thyroid storm in a few cases. The first case, reported in 2020 at Babcock University Teaching Hospital in Nigeria, involved a 55-year-old woman with atypical T4 toxicosis who developed hypermetabolic symptoms, progressing to confusion and loss of consciousness approximately 12 hours after the procedure [6]. The second case, reported in 2023 by the University of Miami School of Medicine in the United States, described a 62-year-old woman with a history of multinodular goiter who underwent FNA of the right thyroid lobe due to compressive symptoms. Within 24 hours, she developed altered mental status, stridor, acute respiratory failure, worsening hypertension, and tachycardia, ultimately requiring intubation [5].

Both previously reported patients developed symptoms within 24 hours of the procedure, whereas our patient presented with symptoms even earlier. FNA of the thyroid gland is a reliable diagnostic tool commonly used in the initial evaluation of thyroid nodules, particularly when ultrasound findings or clinical features raise suspicion of malignancy [9]. However, there was no clear indication of FNA for our patient other than the patient's request. Therefore, we recommend avoiding routine FNA in patients who do not have clear guideline-based indications for the procedure. Additionally, FNA should be postponed until the patient's thyroid function has normalized.

Learning Points

• This case highlights the importance of anticipating thyroid storm, timely recognition, and management of thyroid storm in patients with thyrotoxicosis during FNA, especially on the first day of the procedure.

• FNA of toxic thyroid nodules is rarely indicated in patients with underlying hyperthyroidism.

• Proper preprocedure optimization of thyroid function tests is crucial for favorable outcomes in thyrotoxic patients if FNA is mandatory.

Contributors

All authors contributed individually to authorship. G.A.B. prepared the initial draft. S.K.K., G.E.K., and K.E.B. revised the manuscript. All authors were involved in the management of the patient. All authors reviewed and approved the final draft of the manuscript.

Funding

No public or commercial funding.

Disclosures

None declared.

Informed Patient Consent for Publication

Signed informed consent was obtained directly from the patient.

Data Availability Statement

Original data generated and analyzed during this study are included in this published article.