Cystic Neck Masses: Differential Etiologies and a Case of Suspected Fourth Branchial Cleft Cyst
Poster #: 057
Session/Time: B
Author:
Juan Emilio Ferrando, MS
Mentor:
Christopher O'Neill, MD
Research Type: Case Report
Abstract
INTRODUCTION:
The branchial apparatus is the embryological precursor to many of the structures in the head, face, palate, and anterior neck. It consists of paired arches, pouches, and clefts. When the branchial clefts fail to involute, a cyst, sinus, or fistula can form along its tract. Branchial cleft anomalies account for approximately 20% of congenital cysts in children, with the second branchial cleft being the most common, representing approximately 95% of branchial cleft cysts. The first branchial cleft accounts for approximately 1-4% of branchial cysts. Cysts arising from the third and fourth cleft are considered extremely rare. We report a case of an adult patient with a cystic structure located anteromedially to the left sternocleidomastoid muscle. Based on the location of the cyst, its anatomical relationships, and lack of secondary inflammation there is suspicion for a fourth branchial cleft cyst.
CASE INFORMATION:
A 33-year-old female with a no significant past medical history presented to the emergency department with a painful swelling on the left side of her anterior neck, first noticed approximately one year prior. She endorsed progressive enlargement of the mass for the past month, as well as subjective fevers within the past 3 days. Associated symptoms include dysphonia and neck stiffness. On presentation, the patient had stable vital signs. Physical exam revealed a smooth and immobile left anterior neck mass without erythema. She denies any history of thyroid disease or weight loss. Contrast-enhanced head and neck CT demonstrated a multiseptated 2.4 x 2.2 x 4.5 cm cystic structure anteromedial to the left sternocleidomastoid muscle spanning the C2-C5 cervical levels with associated posterior displacement of the left internal jugular vein and common carotid artery. Pertinent negatives include unremarkable parotid and submandibular glands, no diffuse lymphadenopathy, and clear lungs.
DISCUSSION/CLINICAL FINDINGS:
Branchial cleft cysts are frequently diagnosed in younger individuals and may be asymptomatic initially though may enlarge and predispose to superimposed infection. Many etiologies for lateral neck masses exist, so a broad differential should be considered. In this case, the lack of secondary inflammation lowers suspicion for an infectious etiology. Other etiologies of lateral cystic neck masses include branchial cleft cysts, necrotic lymphadenopathy, vascular malformations, lymphangioma, carotid body tumors, lymphoma, and other malignancies. There are no pathognomonic features of branchial cleft anomalies, which necessitate an understanding of their anatomical relationships and tracts. The fourth branchial cleft tract begins at the apex of the piriformis sinus and descends inferiorly toward the thyroid gland, passing below the superior laryngeal nerve and above the recurrent laryngeal nerve. In this case, the findings are suggestive of a fourth branchial cyst, though definitive anatomical relationship may be definitively evaluated with MR or with surgical correlation.
CONCLUSION:
Branchial cleft cysts can be rare depending on the structure they originate from, and require knowledge about their anatomical relationships, tract, image features, and common presentations to accurately diagnose them. This case demonstrates the anatomical relationships and clinical presentation needed to suspect a fourth branchial cleft cyst.
The branchial apparatus is the embryological precursor to many of the structures in the head, face, palate, and anterior neck. It consists of paired arches, pouches, and clefts. When the branchial clefts fail to involute, a cyst, sinus, or fistula can form along its tract. Branchial cleft anomalies account for approximately 20% of congenital cysts in children, with the second branchial cleft being the most common, representing approximately 95% of branchial cleft cysts. The first branchial cleft accounts for approximately 1-4% of branchial cysts. Cysts arising from the third and fourth cleft are considered extremely rare. We report a case of an adult patient with a cystic structure located anteromedially to the left sternocleidomastoid muscle. Based on the location of the cyst, its anatomical relationships, and lack of secondary inflammation there is suspicion for a fourth branchial cleft cyst.
CASE INFORMATION:
A 33-year-old female with a no significant past medical history presented to the emergency department with a painful swelling on the left side of her anterior neck, first noticed approximately one year prior. She endorsed progressive enlargement of the mass for the past month, as well as subjective fevers within the past 3 days. Associated symptoms include dysphonia and neck stiffness. On presentation, the patient had stable vital signs. Physical exam revealed a smooth and immobile left anterior neck mass without erythema. She denies any history of thyroid disease or weight loss. Contrast-enhanced head and neck CT demonstrated a multiseptated 2.4 x 2.2 x 4.5 cm cystic structure anteromedial to the left sternocleidomastoid muscle spanning the C2-C5 cervical levels with associated posterior displacement of the left internal jugular vein and common carotid artery. Pertinent negatives include unremarkable parotid and submandibular glands, no diffuse lymphadenopathy, and clear lungs.
DISCUSSION/CLINICAL FINDINGS:
Branchial cleft cysts are frequently diagnosed in younger individuals and may be asymptomatic initially though may enlarge and predispose to superimposed infection. Many etiologies for lateral neck masses exist, so a broad differential should be considered. In this case, the lack of secondary inflammation lowers suspicion for an infectious etiology. Other etiologies of lateral cystic neck masses include branchial cleft cysts, necrotic lymphadenopathy, vascular malformations, lymphangioma, carotid body tumors, lymphoma, and other malignancies. There are no pathognomonic features of branchial cleft anomalies, which necessitate an understanding of their anatomical relationships and tracts. The fourth branchial cleft tract begins at the apex of the piriformis sinus and descends inferiorly toward the thyroid gland, passing below the superior laryngeal nerve and above the recurrent laryngeal nerve. In this case, the findings are suggestive of a fourth branchial cyst, though definitive anatomical relationship may be definitively evaluated with MR or with surgical correlation.
CONCLUSION:
Branchial cleft cysts can be rare depending on the structure they originate from, and require knowledge about their anatomical relationships, tract, image features, and common presentations to accurately diagnose them. This case demonstrates the anatomical relationships and clinical presentation needed to suspect a fourth branchial cleft cyst.