To find something that small you'd need to chop the lungs up into fine pieces, and then you can't transplant.

CNN: Why transplants use 'imperfect' organs

The software houses then chop up orders into bite-sized pieces and feed them to thousands of subcontractors.

ECONOMIST: Software in Japan

Imagine subjecting Shakespeare to a computational process like bioinformatics--not to chop the poor guy into DNA base pairs but to tease out 1, 000-word pieces (or strings) of his plays.

FORBES: Magazine Article