While examining the changes one night in late May, she became genuinely frightened.

She went to her computer, searching everywhere for a benign explanation.

She didn’t find one.

“I knew I had breast cancer,” she says.

She agreed that the left breast looked unusual but examined her for lumps and felt none.

It’s not cancer, she told her patient.

But Sherif was still uneasy, so the nurse sent her to a radiologist for an ultrasound exam.

It came back negative.

The radiologist didn’t see any need for a mammogram or MRI.

Sherif was told to wait three months and come back.

The doctor took one look at her inflated breast and ordered a biopsy.

Sherif’s cancer hadn’t metastasized, but at stage III, it was advanced.

Finding their cancer can be fraught with pitfalls.

Doctors should always assume a lump is cancer until they can prove that it is not.

For many women, however, it’s not biology or technology that complicates diagnosis.

A delay in diagnosis is always troubling.

“Young women are dying of this disease,” Padilla says.

She reminisces about a close friend from Harvard University whose cancer was initially misdiagnosed.

“It’s a scandal more attention hasn’t been paid to this.”

Bryn Macari Rudewas relieved and excited to be breast-feeding her 2-week-old daughter, Rylie.

And then, at the age of 36, she felt a lump in her right breast.

Her gynecologist agreed with the initial diagnosis.

In October, she went back a third time, complaining the bump was starting to itch.

“It’s nothing,” the nurse said, though she offered to schedule a mammogram.

Rude finally got her mammogram in November 2003eight months after she’d first noticed the lump.

Her worst fears were confirmed: It was a malignant tumor.

She’s had two surgeries, followed by chemotherapy, radiation and tamoxifen.

“I have awesome doctors,” she says.

“I’ve found the best in the area.

If I hadn’t felt ignored all those months, I might still have faith in the system.

But I’m having trouble getting past that.”

Breast cancer is a relatively common disease.

Many doctors see it every day.

So why do so many women have trouble getting a good diagnosis?

“There are two kinds of patients,” Dr. Norton says.

Others say, ‘Doctor, whatever you do, don’t hurt me.'"

They say it not in so many words but in their demeanor.

“I can tell right away when somebody comes in the door,” Dr. Norton says.

When a patient appears frightened, some doctors may respond with unrealistic reassurance.

Instead, physicians should relay the facts, which are always less scary than imagination, Dr. Norton says.

Every lump should be evaluated.

Many will be benign.

“Early diagnosis is important,” he says.

A delay doesn’t always affect the outcomebut it can.

“So you might as well do the exam as soon as possible,” he says.

“It’s like looking for a polar bear on the ice.”

That’s why mammograms are recommended as a routine screening tool only for women 40 and older.

Two newer diagnostic techniques show promise for young women.

“We found more cancers with no more false positives” compared with traditional mammograms, she says.

For now, however, the two newer technologies are less widely available than mammography and ultrasound.

A digital mammography machine can cost $500,000, and MRI equipment about $1 to $3 million.

And MRI machines are big, meaning installation costs can sometimes double the price.

Digital mammography and MRIs are also expensive for patients, up to $2,000 per screening.

Insurance reimbursements, ranging from $400 to $1,800, often fall short, Dr. Tuvia says.

Doctors, too, may be reluctant to green-light MRIs for younger women.

“We should see more of it.”

“Maureen’s story saves lives.”

“Basically, that’s the right message,” Dr. Mahoney says.

The message to the patient remains clear: Insist on a thorough diagnosis.

It’s a lesson Linda Sherif learned as she underwent chemotherapy, a mastectomy, breast reconstruction and radiation.

She finished active treatment in July 2005.

“Right now, there’s no evidence of disease,” she says.

She’s making plans for the future.

Would she do things differently if she was given another chance?

“Definitely,” Sherif says.

“Doctors are experts, and you want them to be right.

But I’m a lot more assertive now.”