The fascia of the greater pectoral muscle forms the deep margin of the dissection and should be removed with the specimen. ... deep recurrences beneath the reconstruction are comparatively uncommon.

This extends from the skin to the deep fascia of pectoralis major (chest wall muscle). It is a combination of fat and dense fibrous tissue which makes up the corpus mammae (body of the breast) ...

Outcome comparisons were made between the fascia-excised and the fascia-preserved groups. Median follow-up was 1,547 days. The researchers found that the mean Breslow depth was 4.2 millimeters.