phantom tumor
Webster's Dictionary (GCIDE)
Phantom \Phan"tom\, n. [OE. fantome, fantosme, fantesme, OF. fant[^o]me, fr. L. phantasma, Gr. fa`ntasma, fr. fai`nein to show. See Fancy, and cf. Pha["e]ton, Phantasm, Phase.] That which has only an apparent existence; an apparition; a specter; a phantasm; a sprite; an airy spirit; an ideal image. [1913 Webster]
Strange phantoms rising as the mists arise. --Pope. [1913 Webster]
She was a phantom of delight. --Wordsworth. [1913 Webster]
Phantom ship. See Flying Dutchman, under Flying.
Phantom tumor (Med.), a swelling, especially of the abdomen, due to muscular spasm, accumulation of flatus, etc., simulating an actual tumor in appearance, but disappearing upon the administration of an an[ae]sthetic. [1913 Webster]