A three-year-old girl from east China is making a full recovery from breast cancer after becoming one of the youngest person ever to be diagnosed with the disease.

The girl from Shandong province, nicknamed Yan Yan, was diagnosed with secretory breast carcinoma, a rare form of breast cancer after her mother first noticed a mysterious lump on her chest.

Doctors in Jiangsu People's Hospital were able to remove the tumour while preserving the mammary glands in an hour-long operation, Chinese media reported.

Three-year-old Yan Yan (pictured) from east China is making a full recovery from breast cancer after becoming one of the youngest person ever to be diagnosed with the disease

During a carefully-planned operation, breast cancer specialist Tang Jin Hai (pictured) and his team removed the tumour while preserving the mammary glands

Her mother told Modern Express that she first noticed a red, sticky discharge left on Yan Yan's shirt during a bath in March.

A couple of weeks later, the girl's condition did not improve and her mother was shocked to find a small lump on her chest.

She quickly took her daughter to the doctor, who said Yan Yan was just experiencing early puberty and had asked the parent to 'stop giving her too much nutrition'.

The worried mother sought a second opinion in nearby province Jiangsu, where doctors promptly ordered a full checkup including a biopsy after discovering a swollen lymph node in her armpit.

Volunteers and social workers visit Yan Yan at hospital before her surgery in Jiangsu province

Yan Yan was discharged from hospital on Monday and is expected to make a full recovery

What is secretory breast carcinoma? Secretory breast carcinoma (SBC) is a very rare, slow-growing type of breast cancer. It was originally referred to as 'juvenile breast carcinoma' because it was first recognised in children and adolescents, more commoly in females. Signs and symptoms of SBC most commonly include a painless, firm mass in the breast, which may move when palpated. Some people with SBC also have nipple discharge. Options for treatment may include surgery to remove the tumour or breast (mastectomy), surgery to also remove nearby lymph nodes, radiotherapy, and chemotherapy. SBC is usually associated with an excellent prognosis (prolonged survival), even when it spreads to the lymph nodes. Source: National Institutes of Health Advertisement

The lump on her chest was revealed to be a case of secretory breast carcinoma, a slow-growing type of breast cancer where patients often develop a painless, firm mass in the breast, which may move when palpated, according to the US National Institutes of Health.

During a carefully-planned operation, breast cancer specialist Tang Jin Hai and his team removed the tumour and the sentinel lymph node for a biopsy, which is where the cancer would spread to first.

Luckily, they were clear - meaning she did not need chemotherapy or radiotherapy and that the cancer had not spread to the nearby lymph nodes.

Yan Yan was discharged from hospital on Monday and is expected to make a full recovery, according to the report.

Breast cancer is the most common cancer in women, with 80 per cent of the disease occur in women over the age of 50, according to Breast Cancer Care, meaning it is extremely rare for toddlers to be diagnosed.

Young children and adolescents have just a 0.1 per cent chance of developing breast cancer, an expert previously told Fox News in a similar case in 2009 when 10-year-old Hannah Powell-Auslam from California was diagnosed with invasive ductal carcinoma, an adult cancer.

In 2010, Aleisha Hunter, a four-year-old girl from Ontario, Canada was also diagnosed with secretory breast carcinoma, the same condition as Yan Yan.