barw Judi Clinical Journal 3105-4102 1 1 2025 06 10 Thyroid Hemiagenesis: A Single-Center Case Series 7 11 10.70955/JCJ.2025.3 eng Abdulwahid M. Salih Scientific Affairs Department, Smart Health Tower, Madam Mitterrand Street, Sulaymaniyah, Iraq 0009-0006-5546-5878 Hiwa O. Baba Scientific Affairs Department, Smart Health Tower, Madam Mitterrand Street, Sulaymaniyah, Iraq Shaho F. Ahmed Endocrinology Department, Shar Hospital, Malik Mahmud Ring Road, Sulaymaniyah, Iraq Karzan M. Salih Scientific Affairs Department, Smart Health Tower, Madam Mitterrand Street, Sulaymaniyah, Iraq Abdullah A. Qadir Scientific Affairs Department, Smart Health Tower, Madam Mitterrand Street, Sulaymaniyah, Kurdistan, Iraq Ayman M. Mustafa Scientific Affairs Department, Smart Health Tower, Madam Mitterrand Street, Sulaymaniyah, Kurdistan, Iraq Shko H. Hassan Scientific Affairs Department, Smart Health Tower, Madam Mitterrand Street, Sulaymaniyah, Kurdistan, Iraq. Harun A. Ahmed Scientific Affairs Department, Smart Health Tower, Madam Mitterrand Street, Sulaymaniyah, Kurdistan, Iraq Aras J. Qaradakhy Department of Radiology, Shorsh Teaching Hospital, Sulaymaniyah, Kurdistan, Iraq Rebaz O. Mohammed Scientific Affairs Department, Smart Health Tower, Madam Mitterrand Street, Sulaymaniyah, Iraq Aso N. Qadir Scientific Affairs Department, Smart Health Tower, Madam Mitterrand Street, Sulaymaniyah, Kurdistan, Iraq Ahmed H. Ahmed Scientific Affairs Department, Smart Health Tower, Madam Mitterrand Street, Sulaymaniyah, Kurdistan, Iraq. Dindar H. Hama Scientific Affairs Department, Smart Health Tower, Madam Mitterrand Street, Sulaymaniyah, Iraq Rawand R. Rafiq Scientific Affairs Department, Smart Health Tower, Madam Mitterrand Street, Sulaymaniyah, Iraq 2025 05 17 Introduction: Thyroid hemiagenesis (TH) is a rare congenital anomaly characterized by the complete absence of one thyroid lobe, with or without absence of the isthmus. Its etiology remains unclear, and epidemiological data are limited. Although TH is often asymptomatic and discovered incidentally, it may pose clinical challenges when accompanied by thyroid dysfunction or structural abnormalities. This study reviews a single-center experience in diagnosing this condition and highlights its clinical significance.. Methods: This single-center case series was conducted from July 2021–July 2024, analyzing TH cases confirmed via ultrasonography. Eligible patients had complete medical records, including demographics, clinical presentation, radiological findings, and thyroid function status. Data were retrieved from electronic records and analyzed using SPSS 27.0, employing descriptive statistics to summarize means, ranges, frequencies, and percentages, ensuring a comprehensive assessment of TH clinical and epidemiological characteristics.. Results: This study analyzed 11 patients with TH (mean age: 28.12 ± 18.14 years; range: <1–55 years), seven of whom were females (63.6%). The diagnosis was incidental in six cases (54.5%), while three (27.3%) presented with neck swelling and two (18.2%) with neck pain. Thyroid function was euthyroid in seven (63.6%), hyperthyroid in two (18.2%), and hypothyroid in two (18.2%). Ultrasound examination confirmed left lobe and isthmus agenesis in eight cases (72.7%). Follow-up ranged from 4 to 48 months. Conclusion: This study confirms the female predominance of TH, with left-lobe absence being the most common. Congenital anomalies suggest embryological links. While thyroid function is typically preserved, those with hypo- and hyperthyroidism highlight the need for individualized endocrine assessment and monitoring.