Axillary Tail of Spence

Expansion

• The breast normally extends from the second to the sixth rib, and from the sternal edge to the mid-axillary line
• The axillary tail of Spence is a prolongation of the upper outer quadrant that pierces the deep fascia at the foramen of Langer to enter the axilla

Two practical consequences. First, an examination that stops at the anterior axillary fold misses real breast tissue, so the axillary tail must be palpated. Second, a lump in the axilla may be breast tissue rather than a node, and can develop the same pathology, including carcinoma and cyclical tenderness.