A breast cancer diagnosis can stop you in your tracks, bringing new emotions and concerns about your future. Surgery is almost always needed to treat breast cancer, which may trigger worry about what you will look like afterward.

A lumpectomy — more accurately referred to as a partial mastectomy — is performed when the cancerous tissue and a small amount of tissue surrounding it are removed. The doctor removes the tumor while leaving much of the healthy breast tissue left in place.

A mastectomy is the other main type of breast cancer surgery. You might already know it's very different from a lumpectomy, but did you know that, if the cancer was found during a screening mammogram, the decision to have a mastectomy is often an option rather than a requirement?

"For small, mammogram-detected cancers, whether you have a lumpectomy or mastectomy is almost always a personal choice," explains Dr. Candy Arentz, a breast surgical oncologist at Houston Methodist. "And there are many factors to take into account before making that decision."

When weighing your options, your oncologist can help you make an informed decision based on facts, not fears. Here's everything you need to know about having a mastectomy, including how it differs from lumpectomy and what to expect after the procedure.

What is a mastectomy?

In contrast to lumpectomy, which removes just part of the breast, mastectomy is the removal of the entire breast.

"We work hard to save as many of the important landmarks of the breast — the skin, nipple and areola — during a mastectomy whenever possible," says Dr. Warren Ellsworth, a breast reconstructive surgeon at Houston Methodist. "To do this, we have to be very thoughtful about the treatment plan, which requires close collaboration between the breast surgeon and reconstructive surgeon right from the start."

Depending on the stage and type of breast cancer, there are a few different ways a mastectomy can be performed, including:

• Nipple-sparing mastectomy – removes breast tissue while leaving the skin, nipple and areola intact
• Skin-sparing mastectomy – removes breast tissue, as well as the nipple and areola, while leaving the skin intact
• Total mastectomy – removes the entire breast, including the skin, nipple and areola

Breast reconstruction, using either an implant or the patient's own tissue, is then performed. At Houston Methodist, this almost always happens immediately, with reconstructive surgeons doing their work right after the breast surgeon completes the mastectomy. That isn't necessarily the case at some hospitals, a matter worth inquiring about before deciding on the plan for treatment, as immediate reconstruction decreases the risk of emotional difficulties than can come with delayed reconstruction. (Related: 5 Things to Know About Breast Reconstruction)

"The literature shows that waking up from a mastectomy with a reformed, reshaped breast is proven to be psychosocially beneficial for a woman," says Dr. Ellsworth.

When is a mastectomy needed for breast cancer treatment?

Sometimes a mastectomy is the patient's choice. Other times it's not.

If a tumor is large, there are multiple tumors or the cancer doesn't form a distinct lump, as is the case with inflammatory breast cancer, a mastectomy is often required to effectively treat the disease.

But if the tumor is caught early or if it's small relative to the size of the breast, your oncologist will likely offer a choice between mastectomy and lumpectomy. What should a woman consider when making that decision?

"Some women choose a mastectomy over a partial mastectomy out of fear, but I always explain that neither recurrence rate nor overall survival are determined by which you choose," says Dr. Arentz.

The decision should instead be made based on personal and lifestyle factors. For instance, the radiation required after a lumpectomy can be a logistical hurdle for some.

"A partial mastectomy is followed by radiation therapy every day Monday through Friday for four weeks, meaning a total of 20 treatments," says Dr. Arentz. "This isn't as much of an issue for our local patients since we offer radiation therapy at locations across Houston, but it can be a barrier for patients who have to travel to Houston for treatment."

Or perhaps a woman might choose a mastectomy because genetic testing has revealed she's at higher risk for getting a second breast cancer. Complete removal of breast tissue via mastectomy eliminates this risk. She might also choose to prophylactically remove her other, healthy breast as well, which is called bilateral mastectomy. (Related: Cancer Genetic Counseling: Can Hereditary Cancer Be Prevented?)

"While not a requirement for effectively treating her current breast cancer, in a case like this it makes clinical sense to totally remove one or both breasts to help prevent a second breast cancer," says Dr. Ellsworth. "Even someone who doesn't have a gene mutation related to breast cancer might still opt to remove both breasts for psychosocial reasons — wanting both sides of her chest to match as closely as possible."

What does your chest look like after a mastectomy?

Some comforting news: Women who undergo breast reconstruction immediately after mastectomy can expect to wake up from surgery looking very similar to how they went to sleep.

"It's why we work so hard to seamlessly coordinate breast cancer treatment this way," says Dr. Arentz. "A woman often sees her breast and reconstructive surgeons on the same day when first diagnosed, so that all of these things can be thoughtfully put together ahead of time, and she can move through her procedure without ever having a time without a reconstructed breast."

This is distinctly different from how mastectomies were performed even just a decade ago.

As for the specifics of what a woman's chest looks like afterward, that varies depending on the type of breast reconstruction chosen:

• Implant-based reconstruction
• Tissue-based reconstruction

"For implant-based reconstruction, we use liposuction to inject fat around the implant and make the breast look and feel as natural as possible," says Dr. Ellsworth. "But implants don't last forever — around 15 years or so — and complications like infection and rupture are factors to consider."

He points out that, through implant-based clinical trials, newer, improved breast implant options that reduce such risks are available. (Related: Do Breast Implants Affect Mammograms?)

Tissue-based reconstruction, also called the flap procedure, uses your own tissue — typically taken from your belly — to rebuild your breast. This is a much more complicated reconstruction, but it results in a more natural looking and feeling breast. It also lasts forever and offers the chance to bring life back to the chest.

"To help improve a woman's chance of regaining sensation in her breast, we can also dissect nerves in the tummy and reconnect them to ones in the chest," explains Dr. Ellsworth. "This new technique requires an experienced reconstructive surgeon and is currently only offered as part of a clinical trial, but we've seen remarkable results using this technique."

Mastectomy recovery: How long does it take?

A mastectomy is an outpatient procedure, with the vast majority of patients returning home the same day. Recovery can vary depending on the type of reconstruction chosen, but it typically takes around a month.

"If there's no reconstruction at all, which some women do choose since it's the simplest, easiest procedure, recovery takes about two weeks," says Dr. Arentz. "After this, women are usually able to resume normal activity."

Implant- and tissue-based reconstruction lengthen this timeline slightly, with recovery taking around four weeks and six weeks, respectively.

By contrast, a lumpectomy is a simpler procedure, and normal activity can typically be resumed within one to two weeks of surgery.

Life after mastectomy: Do you still need screening mammograms?

One benefit that many women consider while making their decision: having a mastectomy means that for the rest of your life, you no longer need mammograms for the one breast if it was a single mastectomy, for both if it was a double mastectomy.

"It's a bigger surgery up front, but then you're done," says Dr. Arentz. "A woman who chooses a lumpectomy will have to continue to do mammograms, and sometimes MRI, at the cadence recommended by her doctor."

Dr. Ellsworth adds that never needing to be screened for breast cancer again is a psychosocial benefit for some women.

"After going through surgery and potentially chemo and so on, many women find it hard to even think about needing a mammogram again," explains Dr. Ellsworth. "Mastectomy provides relief from the dread of more screenings and potentially even another diagnosis in the future."