An Auckland mother of four who had a preventative double mastectomy, only to be diagnosed with an extremely rare cancer, has died, aged 40.

Hibiscus coast hairdresser Melissa Galley lost her battle with a cancer that began in a nerve in the back of her nose -- called olfactory esthesioneuroblastoma.

She died on July 6, leaving behind her two sets of teenage twins Blake, Jacob, Lily and Carson, and her husband and childhood sweetheart Karl.

But Galley's battle with cancer began long before she was first diagnosed with the disease in 2014.


When she was just 13 years old, her mother died of breast cancer, and in 2010 Galley found she carried the BRCA2 gene mutation -- which greatly increases the risk of breast cancer in those who carry it.

In 2010 she had a double mastectomy -- an operation to remove both breasts in order to reduce the risk of the mutation causing breast cancer, which hit headlines when actress Angelina Jolie wrote about her own experience of the surgery in the New York Times in 2013.

But in September 2014, the mother of four was diagnosed with olfactory esthesioneuroblastoma, a rare and malignant tumour on a nerve in the nose.

The cancer is known for its rarity, variety of symptoms, rapid progression and delayed detection, and is associated with high rates of tumour recurrence and death.

The following month, Galley had five weeks of radiotherapy followed by surgery to remove the tumour.

But in May last year she was given the heartbreaking news that she had another aggressive, fast-growing tumour behind her eye.

Surgery to remove the tumour meant the loss of her right eye, but the brave mum remained positive and humorous.

To help pay for treatment and support Galley and her young family, more than 200 people donated more than $38,000 through Givealittle.

Last week, Galley died peacefully with her family by her side.

Her funeral will be held on Wednesday.

What is olfactory esthesioneuroblastoma?

A rare cancer, olfactory esthesioneuroblastoma is a tumour that grows in the sinus region, behind the nose. It's known for its rarity, variety of symptoms, rapid progression and delayed detection. A 1997 study published in academic journal Anticancer Research found only about 1000 cases had been identified since the first case was described in 1924. The most notable case of the cancer in recent years was that of French woman Chantal Sebire. The cancer spread through Sebire's sinuses, Nasal cavities and eye socket, leaving her face severely disfigured, and she unsuccessfully battled in court for the right to die. In 2008 she died at her home near Dijon, aged 52 and was found to have a toxic concentration in her system of a drug used in some parts of the world in physician-assisted suicide.