CASE REPORT |
https://doi.org/10.5005/jp-journals-10002-1455 |
A Rare Case of Thyroid Hemiagenesis with Graves Disease
1–6Department of Endocrine Surgery, Madras Medical College, Chennai, Tamil Nadu, India
Corresponding Author: Aneesh Sugunan, Department of Endocrine Surgery, Madras Medical College, Chennai, Tamil Nadu, India, Phone: +91 9995401597, e-mail: sugu555@gmail.com
Received on: 28 November 2021; Accepted on: 08 August 2023; Published on: 30 October 2023
ABSTRACT
Background: Hemiagenesis of the thyroid is a rare congenital condition that is characterized by an absence of a thyroid lobe. The prevalence rate of hemiagenesis is about 0.02% and is usually detected incidentally. Hemiagenesis of the thyroid gland is a rare congenital anomaly with about 800 cases reported in the literature untill 2020.
Case description: A 36-year-old female presented with complaints of weight loss, palpitation, and tremors for the past 3 months. She also gives a history of right-sided neck swelling of a duration of 1 month. A thyroid function test was done and revealed a hyperthyroid state (free T4:3.2 ng/dL, free T3:12.7 pg/mL, TSH: <0.005 mIU/mL). Ultrasound revealed a diffusely enlarged (4.5 × 3.5 × 3 cm) heterogenous hypoechoic right lobe with increased vascularity on Doppler and isthmus of thickness 7.9 mm and an absent left lobe. Thyroid scintigraphy revealed an increased uptake of 8% in the right lobe and isthmus with absent uptake of tracer in the left lobe. A thyroid antibody panel was done and it revealed elevated levels of anti-thyroid stimulating hormone (TSH) receptor antibodies and anti-thyroid peroxidase (TPO) antithyroid microsomal antibody (AMA) antibodies. She attained a clinical and biochemical euthyroid state after 3 months of medical treatment and was admitted and planned for total thyroidectomy. The final histopathology report was suggestive of hyperplastic goiter with an absent left thyroid lobe.
Conclusion: Thyroid hemiagenesis is a rare congenital anomaly of the thyroid gland and when suspected the diagnosis should be confirmed by an ultrasound neck and a thyroid scintigraphy scan.
Clinical significance: Patients with hemiagenesis of the thyroid have a higher risk of developing thyroid disorders and should be kept under close follow-up to diagnose them early for a better outcome.
How to cite this article: Sugunan A, Hussain SZ, Palaniappan KM, et al. A Rare Case of Thyroid Hemiagenesis with Graves Disease. World J Endoc Surg 2023;15(2):50–52.
Source of support: Nil
Conflict of interest: None
Patient consent statement: The author(s) have obtained written informed consent from the patient for publication of the case report details and related images.
Keywords: Autoimmune disease, Case report, Graves disease, Hyperthyroidism, Thyroid hemiagenesis
BACKGROUND
Hemiagenesis of the thyroid is defined as the absence of a thyroid lobe. The incidence of hemiagenesis is about 0.02 % and is usually asymptomatic.1 The exact etiology of how hemiagenesis occurs is still not well explained.2 It is usually due to an impairment or lobulation defect. Thyroid disorders like graves, thyroiditis and nodules can also be seen in patients with thyroid hemiagenesis.3
CASE DESCRIPTION
A 36-year-old female presented with complaints of weight loss, palpitation and tremors for 3 months. She had no complaints of watering of eyes, redness, proptosis, or any visual disturbances. She also gives a history of right-sided neck swelling of 1 month duration. On examination, she had fine tremors with tachycardia and a pulse rate of 124/minute. Examination of the neck revealed a diffusely enlarged right lobe of the thyroid of size 4.5 × 3 cm, firm, nontender, smooth surface with well-defined margins and the lower border of the right lobe was well appreciated. No cervical nodes were palpable and bilateral carotid arteries were felt equally on both sides with the trachea slightly deviated to the left side.
An initial thyroid function test was done, which revealed a hyperthyroid state (free T4:3.2 ng/dL, free T3:12.7 pg/mL, and TSH: 0.015 mIU/mL). A thyroid scintigraphy and ultrasound neck and thyroid were done. Ultrasound revealed a diffusely enlarged (4.5 × 3.5 × 3 cm) heterogenous hypoechoic right lobe with increased vascularity on Doppler and isthmus of thickness 7.9 mm and an absent left lobe (Figs 1 and 2). The estimated volume of the thyroid was 22.6 mL. Thyroid scintigraphy revealed an increased uptake of 8% in the isthmus and right lobe with no uptake of tracer in the left lobe (Fig. 3). A thyroid antibody panel was done and it revealed elevated levels of anti-thyroid stimulating hormone (TSH) receptor antibodies and anti-thyroid peroxidase (TPO) antithyroid microsomal antibody (AMA) antibodies.
Fig. 1: Ultrasound thyroid showing absent left lobe of the thyroid
Fig. 2: Ultrasound thyroid showing enlarged right lobe and isthmus
Fig. 3: Thyroid scintigraphy showing increased tracer uptake in the right lobe
She was given the options of both radioiodine therapy and surgery and she opted for surgical management and, hence, was started on carbimazole (15 mg ter in die [TID]) and β-blockers (propranolol 40 mg TID). She attained a clinical and biochemical euthyroid state after 3 months of medical treatment and was admitted and planned for total thyroidectomy. Intraoperatively right lobe and isthmus were enlarged with increased vascularity with an absent left lobe as noted in the ultrasound (Fig. 4). The postoperative recovery was uneventful and she was discharged after 3 days. The final histopathology report was suggestive of hyperplastic goiter with an absent left thyroid lobe. She was then started on levothyroxine 100 mcg once daily and is on regular follow-up to date without any complications or recurrences (Fig. 3).
Fig. 4: Excised specimen showing right lobe, isthmus, and pyramidal lobe (suture applied)
DISCUSSION
Hemiagenesis of the thyroid gland is uncommon and only about 800 cases are reported in the literature untill 2020.4 Patients with thyroid hemiagenesis are usually clinically euthyroid and asymptomatic. However, our patient was clinically and biochemically suggestive of having Graves disease. Many studies revealed a more frequent chance of developing thyroid diseases such as Graves disease, thyroiditis, subacute thyroiditis, multinodular goiter, functional, and nonfunctional adenomas, in patients with thyroid hemiagenensis when compared to subjects with normal thyroid anatomy. The most common disorders seen were multinodular goiter and autoimmune thyroid disorders.5,6 Thyroid hemiagenesis is more common in women and affects commonly the left lobe of the thyroid.7
Ultrasonography neck and thyroid scintigraphy are the choice of imaging modalities in the evaluation and diagnosis of suspected thyroid hemiagenesis.8 Ultrasound of the thyroid gland is easy to perform, cheap, and with no radiation exposure.9 Thyroid ultrasound also helps to visualize the absence of the thyroid lobe and the presence of isthmus if any. Thyroid scintigraphy also confirms the diagnosis of hemiagenesis and determines if there is any ectopic thyroid tissue. The image usually shows an increased tracer uptake in one lobe of the thyroid.10 In this patient the diagnosis was done using ultrasound of the neck, followed by a thyroid scintigraphy and a final histopathology report of hemiagenesis (Fig. 4).
CONCLUSION
Hemiagenesis of the thyroid is an anomaly of the thyroid gland which is encountered rarely and when suspected the diagnosis should be confirmed by an ultrasound neck and a thyroid scintigraphy scan. In this patient, thyroid hemiagenesis was seen as associated with Graves disease and was treated successfully surgically with no postoperative complications.
Clinical Significance
Patients with hemiagenesis of the thyroid have a higher risk of developing thyroid disorders and should be kept under close follow-up to diagnose them early for a better outcome.
ORCID
Aneesh Sugunan https://orcid.org/0000-0001-8917-6296
Boddukara Sahithi Priya https://orcid.org/0000-0002-3585-5143
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