What is the diagnosis and treatment for a lipoma in the breast?

From the Guidelines

A lipoma in the breast can be managed with clinical follow-up if mammography or DBT shows a definite benign mass that correlates with the palpable finding, and there is no need for short-interval imaging follow-up. When a lipoma is suspected, diagnosis typically involves a physical examination and imaging tests like mammogram or digital breast tomosynthesis (DBT) 1. According to the ACR Appropriateness Criteria, for a woman 40 years of age or older with a palpable breast mass and mammography findings benign (like lipoma) at the site of the palpable mass, the next examination to perform is mammography or DBT short-interval follow-up 1. However, if the mammography or DBT shows a definite benign mass, such as a lipoma, that unequivocally correlates with the palpable finding, clinical follow-up is appropriate management.

Some key points to consider when managing a breast lipoma include:

• Clinical follow-up is sufficient if the lipoma is confirmed by imaging 1
• Short-interval imaging follow-up is not necessary if the lipoma is definitively diagnosed 1
• DBT can be helpful in characterizing lesion margin and accurate in characterizing masses according to BI-RADS classification 1
• Surgical removal may be considered if the lipoma causes discomfort or cosmetic concerns, but it is not typically necessary.

It is essential to note that while lipomas are benign, it is crucial to have any new breast lump evaluated by a healthcare provider to confirm the diagnosis and rule out other conditions 1. Regular breast self-exams and routine mammograms remain important for overall breast health, even if you've been diagnosed with a lipoma.

From the Research

Diagnosis of Lipoma in Breast

• Lipoma of the breast can be difficult to diagnose due to its similarity to other conditions, with a clinical diagnosis being incorrect in 25.0% of cases 2.
• Fine-needle aspiration cytology (FNAC) may not be helpful, with only 74.0% of cases revealing fat cells 2.
• Mammography and ultrasound scanning are often negative, with lipoma being revealed in only 3.0% and 21.0% of cases, respectively 2.

Management of Lipoma in Breast

• A proposed management plan involves confirming a clinical diagnosis of lipoma through either FNAC revealing fat cells or a core biopsy consistent with a lipoma 2.
• Mammography and ultrasound are not necessarily required to demonstrate a lipoma, but should not show any signs of malignancy at the site 2.
• If these criteria are met, it may not be necessary to excise the tumor 2.

Biopsy and Imaging

• Core needle biopsy (CNB) can be a useful adjunct to fine-needle aspiration in select patients with palpable breast lesions, particularly in cases where a definitive diagnosis cannot be made by FNA alone 3.
• Radiographic features, such as intramuscular location, septations, nonfat nodules, heterogeneity, and ill-defined margins, can guide the need for CNB in lipomatous masses 4.
• Lipomatous masses smaller than 5 cm without concerning clinical characteristics may not require preoperative imaging or CNB 4.

Types of Lipomatous Tumors

• Lipoma is the most common lipomatous tumor arising in the breast, but other types of lipomatous tumors, such as fibroepithelial tumors and myofibroblastoma, can also occur 5.
• Liposarcomatous components can arise in malignant phyllodes tumors, and primary liposarcomas of the breast are believed to be uncommon 5.