Fourth Branchial Cleft Cyst with Concurrent Congenital Absence of the Contralateral Thyroid Lobe
University of Texas Medical Branch
Introduction: Branchial cleft abnormalities originate from errors during embryogenesis, resulting in incomplete involution of branchial clefts. Fourth branchial cleft cysts are particularly rare, accounting for less than 3% of all branchial anomalies. Removal of the cyst is necessary to prevent infection and obstruction. Treatment for a fourth branchial cleft cyst has historically been complete surgical excision, but successful endoscopic removal has also been demonstrated Case Description: A 3 year old female was referred to pediatric surgery for a left sided neck mass. The mass was soft, mobile, and non-tender. The overlying skin was intact with no signs of infection or drainage. The patient denied any compressive symptoms such as dyspnea or dysphagia. Management: Ultrasound imaging of the head revealed a cystic lesion, measuring 3.7 cm, suspected to be a cystic hygroma. An MRI demonstrated a well-defined, nonenhancing homogenous lesion located in the left neck, lateral to the midline. According to the imaging, the mass was located in an anatomic position consistent with a fourth branchial cleft cyst. The patient was taken to the operating room for excision. Intraoperative findings were significant for a congenital absence of the right thyroid lobe. Discussion: The most common treatment for a fourth branchial cleft cyst is complete surgical excision of the cyst. A portion of the thyroid gland may need to be removed if it is involved with the cyst. Due to the complex anatomic course of fourth branchial arch anomalies, there exists a risk of injuring the recurrent laryngeal during the procedure. Minimally invasive endoscopic cauterization has been suggested in younger patients and has been shown to be more cost-effective with lower complication rates compared to a surgical approach. Another treatment option is sclerotherapy with OK-432 which has shown to be effective in achieving regression and cyst reduction, however subsequent surgical excision is often required as well. In the case of our patient, complete surgical excision of the cyst was achieved, and the patient’s post-operative course was uneventful. She was discharged home on post-operative day one with no signs of hoarseness or dysphagia. Patient was seen as an outpatient for follow-up and she was progressing as expected with adequate healing of her wound.