A 28-year-old woman presents with a 3 cm fluctuant, non-tender swelling in the left posterior triangle of the neck, just anterior to the sternocleidomastoid muscle. Fine needle aspiration yields clear fluid. This is most likely a cystic hygroma. Which fascial space or triangle does this lesion typically occupy?

• A Submandibular triangle
• B Carotid triangle
• C Occipital triangle
• D Posterior triangle ✓

Explanation

A cystic hygroma is a congenital lymphatic malformation that most commonly presents in the posterior triangle of the neck, often extending into the axilla. The posterior triangle is bounded by sternocleidomastoid anteriorly, trapezius posteriorly, and the clavicle inferiorly. The occipital triangle is a subdivision of the posterior triangle but the lesion classically occupies the posterior triangle proper.

Reference: Gray's Anatomy for Students, 4th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.