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.
If you have noticed a black pepper type substance growing in your toilet tank, it is most likely Cladosporium, the most common of all molds. It is categorized as Black Mold and the genus is Cladosporium, which includes over 30 species. The differences can only be detected under a microscope.