The patient's teratoma contained primitive brain cells that leaked into his bloodstream, triggering an autoimmune response where antibodies attacked both the foreign cells and his own brain tissue. The primitive cells also underwent rapid malignant transformation, creating multiple tumors throughout his body that eventually collapsed under their own growth.
Also known as: Brain inflammation from immune system
Secondary to the teratoma, the patient's immune system created antibodies against primitive brain cells that cross-reacted with his own neural tissue, causing seizures and paralysis. This was the primary manifestation of his illness throughout most of the episode.
Also known as: Multiple cancers
The patient developed three apparently unrelated cancers simultaneously in different organs (pancreas, kidney, colon), which were actually rapidly growing primitive cells from the teratoma that transformed into malignant tumors. The team initially considered this a multicancer syndrome before discovering the true cause.
Cuddy's mother is recovering from a hip replacement surgery that was complicated by House's unauthorized medication switch in a previous episode. Her slow recovery is causing conflict between her and Cuddy, leading to threatened litigation against the hospital.