Benign Brenner tumour of the ovary

What is a benign Brenner tumour?

A benign Brenner tumour is a rare non-cancerous ovarian tumour. These tumours may not cause any symptoms and may only be recognized by your pathologist after the ovary has been removed for other reasons. Occasionally benign Brenner tumours can be large, causing symptoms such as pelvic pain.

The ovary

The ovaries are part of the female reproductive tract. They are small organs that are attached to the uterus by the fallopian tubes. The outer surface of the ovaries are lined by a thin layer of specialized epithelial cells that form a barrier around the outside of the ovary called the epithelium. The ovaries also contain large cells called eggs. The tissue below the epithelium is called the stroma.

How do pathologists make this diagnosis?

The diagnosis can be made after the tumour is removed and tissue is examined under the microscope by a pathologist. When the tumour is examined under the microscope, it is made up of specialized epithelial cells called transitional-type epithelium. These cells look like the epithelial cells found in the bladder called the urothelium. Benign Brenner tumours are usually solid tumours although the inside of some tumours may show small spaces called cysts.

Other types of Brenner tumours

There are two other types of Brenner tumours that are even rarer than a benign Brenner tumour:

1. Borderline Brenner tumour – This tumour is a non-cancerous ovarian tumour that is typically benign, but can grow back in the same area as the original tumour.

2. Malignant Brenner tumour – This tumour is a type of ovarian cancer. When examined under the microscope the tumour cells look very similar to a type of bladder cancer called urothelial carcinoma.

by Emily Goebel MD FRCPC (updated June 25, 2021)