October 12, 2004

11:47 PM

Crawly linguistics: What is the association between crabs (the crustaceans) and cancer? We all know the zodiac sign of the crab is called "Cancer", Cancer is also the genus of some crabs, and I've just discovered that other crabs are of the genus Carcinus, which sounds very close to "carcinogen". What's the reasoning and history behind this?
posted by Jimbob to (3 comments total)

Hippocrates is credited with naming "cancer" as "karkinoma" (carcinoma) because a tumor looked like a "crab" ("karkinoma" is Greek for "crab") in that there is a central body to a tumor and the tumor extension appeared as the legs of the "crab". -- Source
posted by Nothing at 12:05 AM on October 13, 2004

There are actually a few slightly conflicting stories, but most agree that the name comes from the fact that some tumors look something like crabs.
posted by Nothing at 12:07 AM on October 13, 2004

There's a long history in medicine of naming nasty pathological findings after something you might eat. We used to amuse ourselves by reciting them in medical school.

"Cancer" is Latin for 'crab' - the six legged beasty that they make into a delicious cake along the Chesapeake - no mystery about that.

When tumors metastazise, one of the first steps is crossing stromal or fascial planes. The original clonal expansion of the tumor cell produces a sphere hemmed in by stroma, but as the cells divide they mutate rapidly, and eventually produce a clone that doesn't respect the basement-membrane barrier any more. This clone is produced at a point on the surface of the sphere, and since only that particular cell possesses the property of invasiveness, it grows outward from the sphere rather quickly, which looks like a tendril, or if there are a number of them on the sphere, and you use your imagination, it's like a crab body with a bunch of spindly crab 'legs' sticking off it.

This is apocrypha, as Nothing noted above, but it makes some kind of sense.
posted by ikkyu2 at 11:41 AM on October 13, 2004