Inverted papilloma

Inverted papilloma
Other names	Ringertz tumour
Micrograph of an inverted papilloma of the urinary bladder. H&E stain.
Specialty	Oncology

An inverted papilloma, also known as Ringertz tumour,^[1] is a type of tumor in which surface epithelial cells grow downward into the underlying supportive tissue. It may occur in the nose and/or sinuses or in the urinary tract (bladder, renal pelvis, ureter, urethra). When it occurs in the nose or sinuses, it may cause symptoms similar to those caused by sinusitis, such as nasal congestion. When it occurs in the urinary tract, it may cause blood in the urine.