Body fat can be classified according to physiological function (white fat vs. brown fat) and anatomical location, among other things. It can also be labeled according to characteristic external appearance as in the case of "cellulite." The latter is just ordinary body fat distributed in a peculiar way by the surrounding connective tissue, producing an orange peel look to the skin.
"Descriptive names for cellulite include orange peel syndrome, cottage cheese skin, the mattress phenomenon, and hail damage. Synonyms include: adiposis edematosa, dermopanniculosis deformans, status protrusus cutis, and gynoid lipodystrophy."
"One plausible explanation - which also explains why very few men suffer from cellulite - is based on the composition and behavior of women's fat cells and the connective tissue that holds them in place. Very simply, a woman's connective tissue is very inflexible, so as females gain weight their fat cells expand, and tend to bulge upwards towards the surface of the skin, giving the classic orange-peel appearance of cellulite. In men, not only is there generally less fat on the thighs, but also the outer skin is thicker and thus obscures what is happening to any surplus fat below."
https://en.wikipedia.org/wiki/Cellulite
http://medical-dictionary.thefreedictionary.com/cellulite
http://health.howstuffworks.com/fat-cell1.htm
Other than that, I know of no "celluloid fat" other than a brief and tangential mention of celluloid being used as fillers in the early history of breast augmentation. Of course the use of celluloid and other foreign objects is no longer done to mimic breast tissue, which is mostly glandular fat and connective tissue.
"1903: Charles Miller inserts "braided silk, bits of silk floss, particles of celluloid, vegetable ivory, and several other foreign materials."
http://209.85.173.132/search?q=cache:iLgswQlyBVQJ:phsj.org/wp-content/uploads/2008/11/cosmetic-surgery-past-present-future.ppt+celluloid+fat+%2B+plastic+surgery&hl=en&ct=clnk&cd=6&gl=us&client=firefox-a
I could be wrong, but maybe sometimes "celluloid" is used when "cellulite" is meant, as in the link below (which may not be as bad as mistaking cellulite for cellulitis, an infection of the skin).
https://en.wikipedia.org/wiki/Cellulitis
