Natoma is the name of narrow street/residential alleyway that runs parallel to Market in the SOMA district of San Francisco. It is one of a series of oddly named such streets that stretch from Mission Street to Folsom Street: Minna, Natoma, Tehama, Clementina.
One evening, after a show at the Metreon, Decay-, Netboy, and Nutation were walking through SOMA from the 5th & Mission Garage when it occured to Decay- that "natoma" sounded like some kind of cancer. Taking inspiration from an ex-channel personality, he coined the term malignant natoma, a disease whose symptoms include incredible arrogance and very full, prominent lips. It was later applied to refer to said ex-channel personality.