teratoma. [terâ²ÉtÅâ²mÉ] pl. teratomas, teratomata. a tumor composed of different kinds of tissue, none of which normally occurs together or at the site of the tumor. Teratomas are most common in the ovaries or testes.
The pink-colored film or ring frequently seen on showers, tubs, toilets and pet water bowls is typically caused by growth of the airborne bacteria Serratia marcesens. This harmless nuisance organism reacts with standing water and frequently forms during spring and summer months.
Quick Answer. The most common cause of mold in a toilet bowl is stagnant water. Stagnant water occurs when the toilet is not flushed on a regular basis. Additional causes include mold spore growth in the toilet tank as well as the transfer of mold spores into the toilet bowl via toilet brushes and tools. Continue Reading.