A Rare Case of a Cervical Thymic Cyst Presenting in Adulthood

A Cervical Thymic Cyst in an Adult Female; A Case Report and Comprehensive Literature Review

Introduction: Cervical thymic cyst accounts for (0.3-1) % of cervical cysts in children and are usually present during the first decade of life with few reported cases in adults. Herein, we present a 34-year-old female with a cervical thymic cyst. We conducted a review of all the previously reported cases as well. Case presentation: The patient complained of an anterolateral neck swelling that was noticed one year ago. It was a soft, fluctuant, mobile, non-tender swelling in the midline and the right side of the lower neck. Neck ultrasonography revealed a large thin-walled cyst, with no internal septa, echoes, or solid parts. Post-contrast MRI of the neck showed a well-defined, oblong-shaped, lobulated cystic lesion just beneath the strap muscle. The cyst extended caudally to the superior border of the anterior mediastinum at the level of the upper border of the manubrium sterni. The patient underwent excision of the swelling under general anesthesia via Kocher's collar neck incision. Connection with the thymus gland was detected behind the manubrium sterni which was separated. Pathological examination showed prominent thymic tissue confirming the diagnosis of a cervical thymic cyst. Conclusion: Adult cervical thymic cyst is very rare with a few cases reported in the literature. Surgical excision in symptomatic patients is the treatment of choice. Paper's main novel aspects: • A rare presentation of a cervical thymic cyst in an adult. • A comprehensive literature review including all the previously reported cases in one table.

Excision of rare adult cervical thymic cyst

Cervical thymic cysts (CTCs) represent 1% of all cervical cystic masses. A review of the literature found that CTCs are typically asymptomatic, with a propensity to be left sided. CTCs often require histological evaluation for diagnosis. A 27-year-old male patient presented to an outpatient otolaryngology clinic with worsening bilateral jaw and neck pain and an incidental right-sided neck mass found on cervical MRI. Preoperative differential diagnosis included venolymphatic malformation versus branchial cleft cyst. Histological examination of the excised specimen provided diagnosis of a CTC. Postoperatively, the patient reported improvement in cervical pain. CTCs are a rare cause of lateral neck mass in young adults. Typical presentation included neck enlargement with no symptoms or in some cases compressive symptoms. It is important to consider CTCs when formulating a differential for a lateral neck mass.