Second branchial cleft cysts: variability of sonographic appearances in adult cases

Abstract

Background and purpose: Previous reports have suggested that second branchial cleft cysts (BCCs) appear on sonograms as well-defined, cystic masses with thin walls and posterior enhancement. Previous CT and MR imaging findings, however, have indicated heterogeneity of these masses, and, in our experience, sonography also shows a similar variable appearance. In this communication, we report the cases of 17 patients with second BCCs and document the variability of sonographic patterns.

Methods: The sonograms of 17 adults with second BCCs were reviewed. Only patients with surgical or cytologic evidence of BCCs were included in this study. The features evaluated were the location, internal echogenicity, posterior enhancement, and presence of septa and fistulous tract.

Results: Four patterns of second BCCs were identified: anechoic (41%), homogeneously hypoechoic with internal debris (23.5%), pseudosolid (12%), and heterogeneous (23.5%). The majority (70%) showed posterior enhancement. All were situated in their classical location, posterior to the submandibular gland, superficial to the carotid artery and internal jugular vein, and closely related to the medial and anterior margin of the sternomastoid muscle. Fourteen (82%) of the 17 BCCs had imperceptible walls, and all were well defined. For none of the patients was a fistulous tract revealed by sonography; the presence of internal septations was revealed for three patients.

Conclusion: As previously suggested by CT and MR imaging findings, sonography reinforces that second BCCs in adults are not simple cysts but have a complex sonographic pattern ranging from a typical anechoic to a pseudosolid appearance.

FIG 1.

A, Longitudinal sonogram of an anechoic second BCC (calipers) with posterior enhancement. B, Longitudinal sonogram of a second BCC (open arrows), predominantly hypoechoic with faint internal debris. Note the presence of posterior enhancement. C, Transverse sonogram of a second BCC (straight arrows) with homogeneous, hyperechoic, internal echoes (pseudosolid). Note the lack of posterior enhancement. Curved arrows identify the bifurcation of the carotid artery. Note that no portion of the cyst extends into carotid bifurcation. D, Transverse sonogram of a second BCC (large arrows) with heterogeneous internal echoes, debris, and septa (small arrows). Note the lack of posterior enhancement. Curved arrows identify the bifurcation of the carotid artery. Note that no portion of the cyst extends into carotid bifurcation. E, Transverse sonogram of a second BCC (straight arrows) with thick walls (arrowheads) and internal echoes. Note the lack of posterior enhancement. Curved arrow identifies the common carotid artery.