Lesser supraclavicular fossa

The lesser supraclavicular fossa is defined anatomically as the small triangular depression located above the clavicle, bounded by the sternal and clavicular heads of the sternocleidomastoid muscle. Its floor is formed by the interval between the two heads of the sternocleidomastoid, and it is roofed by skin, platysma, and superficial fascia. This fossa is clinically significant as it overlies important neurovascular structures, including the subclavian vessels and the brachial plexus, and is a common site for palpable lymphadenopathy and other masses.