- "Ah. Well, long story short, it creates explosive tumors."
- ―Doctor Rodney McKay giving a brief description of the device.[src]
The Tumor creation machine was an insidious weapon created by the Lanteans during their tenure in the Pegasus galaxy.
Overview[]

Dr Rodney McKay revealing the device.
The machine, when activated, emitted a very odd type of radiation which affected organic bodies within its reach. The body was infiltrated by millions of irradiated particles that were genetically programmed to enter a body's systems and gather behind the lungs. In time, they begin to collect trace elements from the body to create an explosive compound and develops as a tumor. Once created, the tumor reaches critical mass and explodes thus killing the person infected as well as damaging the surroundings.

A tumor created by the device.
Preliminary studies on those infected by the radiation can show no changes in health but the science involved was quite complicated in the development of the explosive tumors. It was possible to remove the tumors from the body surgically, but they were incredibly delicate and were capable of exploding at any time.
History[]
It was created at some point during the Lantean-Wraith war as one of a number of possible weapons for use against the Wraith. However, it was abandoned early on as its effects were indiscriminate; affecting Ancient and Humans as well. It was left within one of the laboratories at Atlantis.
The weapon was rediscovered by the Atlantis expedition by Doctor Harriet Hewston and James Watson, though they were unaware of its purpose. After being affected by the device's radiation, they returned to duties at which point Doctor Hewston exploded once the tumor developed. Watson was also affected, but his tumor remained stable temporarily, allowing Doctor Carson Beckett time to remove it. During his attempt at delivering it to the explosive team, it detonated, killing Beckett. (SGA: "Sunday")