When you feel a breast lump, your mind may instantly jump to breast cancer, even though most breast lumps aren’t cancerous. Breast lumps can have different characteristics and feel different from one another. Instead of assuming the worst, contact your doctor to find out what’s causing the lump.

A breast lump could be something quite common, like a fibroadenoma, or something rare, like a phyllodes tumor. These two types of breast lumps can feel and look similar, but they’re different conditions that require different approaches to treatment. This article breaks down their similarities and differences.

What Are the Key Differences Between Phyllodes Tumors and Fibroadenomas?

Phyllodes tumors and fibroadenomas have key differences in their symptoms, diagnostic process, and treatment. Getting an accurate diagnosis after you find a breast lump can help ensure you and your doctor determine the right treatment or follow-up plan.

Symptoms: Phyllodes Tumor vs. Fibroadenoma

Both conditions can feel like a breast lump, but other symptoms can differ. The two types of breast lumps can have different textures and may cause different sensations.

Breast fibroadenomas tend not to be painful and can usually move easily under the skin. They can range in size from about 0.4 to 1.2 inches across. Even though a fibroadenoma lump usually isn’t painful, it might feel a little tender around your menstrual period.

Phyllodes tumors are also solid lumps. They may grow quickly and can become large, but some are smaller when first found. As they grow, phyllodes tumors can stretch the breast skin, making it look tight or shiny.

Most malignant phyllodes tumors don’t cause symptoms beyond the breast lump. In rare cases, bone pain may occur if the cancer has spread to the bones.

Risk Factors: Phyllodes Tumor vs. Fibroadenoma

Like many breast conditions, phyllodes tumors and fibroadenomas are much more common in females than in males, according to Cleveland Clinic. Beyond that, the two conditions have different risk factors.

Fibroadenoma Risk Factors

Fibroadenomas can develop during or after puberty and are commonly diagnosed between ages 15 and 35. After menopause, they’re much less likely to develop. Black women are at a slightly higher risk of fibroadenomas than women of other races, according to Cleveland Clinic.

Fibroadenomas appear to respond to hormones such as estrogen, but their exact cause is unknown. They may also grow during times when estrogen levels rise, such as during pregnancy or while taking hormone therapy containing estrogen.

Phyllodes Tumor Risk Factors

Phyllodes tumors most commonly develop in middle age, although they can occur at any age. Having Li-Fraumeni syndrome, a rare inherited disorder that greatly increases your risk of several cancers, is also linked to a higher risk of phyllodes tumors.

Classification: Phyllodes Tumor vs. Fibroadenoma

Once your doctor knows whether a breast lump is a phyllodes tumor or fibroadenoma, they can learn more about what type it is. Each condition has different types.

How Fibroadenomas Are Classified

There are two main types of fibroadenomas:

• Simple fibroadenomas are the more common type. They tend to be smaller than complex fibroadenomas.
• Complex fibroadenomas tend to appear after age 35. Unlike simple fibroadenomas, they can also slightly increase the risk of developing breast cancer in the future.

A biopsy — removing a small sample of tissue so it can be examined under a microscope — can show whether a fibroadenoma is simple or complex.

How Phyllodes Tumors Are Classified

Doctors group phyllodes tumors into three types:

• Benign — Isn’t cancerous but can still grow quickly, change the shape of the breast, and cause pain
• Malignant — Is cancerous and may spread to other parts of the body
• Borderline — Has some features of both benign and malignant tumors, can come back after treatment, and may then be more aggressive

Diagnosis: Phyllodes Tumor vs. Fibroadenoma

Diagnosing a phyllodes tumor or fibroadenoma often starts when a lump is found in the breast. Some fibroadenomas are found during routine breast screening.

Once a breast lump is found, your doctor may recommend tests to find out what it is. These may include a mammogram, breast ultrasound, or breast biopsy.

Imaging tests can give doctors a detailed view of the inside of the breast. However, phyllodes tumors and fibroadenomas can look very similar on imaging tests.

A core needle biopsy may help tell a fibroadenoma from a phyllodes tumor, but it doesn’t always give a clear answer. In some cases, the whole lump must be removed and examined to make a diagnosis.

Fibroadenoma Biopsy Findings

Under a microscope, a simple fibroadenoma has tissue that looks the same throughout. A complex fibroadenoma has tissue that doesn’t look the same throughout. It may also have other features, such as cysts or calcifications (small deposits of calcium).

Phyllodes Tumor Biopsy Findings

Under a microscope, phyllodes tumors show an overgrowth of the breast’s supporting tissue. This tissue often forms a leaflike pattern around breast ducts. Larger phyllodes tumors may also have cysts but rarely have calcifications.

Treatment: Fibroadenoma vs. Phyllodes Tumor

In most cases, fibroadenomas don’t need treatment because they’re not cancerous, usually don’t cause pain, and may even shrink or go away on their own. Your doctor may recommend regular visits or imaging tests to check for changes. Surgery is sometimes recommended to remove a fibroadenoma that is large or painful, grows rapidly, or has other features that need to be checked.

In contrast, treatment is usually recommended for phyllodes tumors, even when they’re benign. The surgeon removes the tumor completely, and they may also remove some healthy tissue around it to lower the chance that the tumor will return.

Radiation therapy may be used after surgery for some malignant phyllodes tumors and other higher-risk cases. Not everyone with a phyllodes tumor needs radiation therapy.

When Should You See Your Doctor?

It’s important to see your doctor about any new breast lump, even if you’ve had a fibroadenoma or another benign breast lump before. Your doctor can check the lump, find out what it is, and determine whether you need treatment or follow-up.

Tell your doctor if a breast lump you already know about seems to be growing or changing in any way. If you’ve been treated for a fibroadenoma or phyllodes tumor, keep your follow-up visits and get any breast screenings your doctor recommends.

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Have you noticed any other differences between a phyllodes tumor and a fibroadenoma? Let others know in the comments below.