MADAM Chin Siew Lain's problems started with a fingernail-size tumour in her cheek 36 years ago.

Doctors told her it was benign, which meant it would not spread to other parts of her body.

But it somehow did. The tumour cells travelled to her pelvic bone and grew into a 13cm-long mass - the size of an ostrich egg.

Madam Chin was 65 when she discovered it three years ago. She then entered an exclusive club of only 43 people worldwide whose benign salivary gland tumours had been reported to have become life-threatening cancers.

NEW LIFE: Madam Chin took three weeks to recover from cryosurgery, performed by Prof Nathan, compared to the nearly two months she spent in bed after conventional surgery.

Her physician, Dr Goh Boon Cher, a senior consultant at the National University Hospital's (NUH) department of haematology-oncology, said hers was a 'very rare' case.

The tumour was uncovered through a scan she underwent on feeling pain on the left side of her pelvis.

Dr Goh and his colleagues, suspecting it had spread from elsewhere, then noticed a small growth on her cheek, just below her left ear. They were to find out from her that she had had it removed four times since 1972, only to have it pop up again.

When it was removed a fifth time, her doctors saw the similarity in the cells of both growths. The bone tumour was given radiation, which stopped its growth and bought her two pain-free years.

Last year, the pain came back: The tumour was on the march again. As chemotherapy was not known to work on this type of tumour, the only option left was surgery, Dr Goh said.

Last November, Assistant Professor Saminathan Suresh Nathan, a consultant at NUH's department of orthopaedic surgery, was slated to remove the tumour through conventional surgery.

But he had to stop the operation midway after removing just part of it because she was losing too much blood.

Nothing more could have been done for her, save for cryosurgery, which involved freezing the tumour with supercooled argon gas and then cutting it out cleanly. Four months ago, Madam Chin underwent this to remove the remaining tumour.

It took her three weeks to recover, compared to the nearly two months she spent in bed after the first operation. That time, her wound took longer to heal because her skin had previously been affected by radiation.

She said: 'The second time was much better. There was not much pain. I'm really grateful.'

Dr Goh is optimistic that she is out of the woods, saying: 'We are hopeful that the tumour can be contained in the pelvis.'

This article was first published in The Straits Times on June 7, 2008.