Which tissue is an example of fatty tissue mentioned for vacuum infiltration?

• A. Breast
• B. Brain
• C. Placenta
• D. Spleen

Answer: (A)

Fatty tissues are rich in adipocytes with large lipid-filled vacuoles, which creates air pockets and makes it harder for embedding medium to fully penetrate during processing. Using vacuum infiltration helps draw fixative and embedding medium into those spaces more effectively, reducing infiltration artifacts and ensuring proper embedding of the tissue.

Breast tissue is the classic example of fatty tissue because it contains abundant adipose tissue. The other tissues listed are not predominantly fatty; brain has lipid components but is not classified as fatty tissue in this context, and placenta and spleen have relatively little adipose content.