LMNOP · Breast Assessment Mnemonic

LMNOP is a mnemonic device that highlights the most important signs of breast cancer. Breast cancer is the most common cancer in genetic females, although it can also occasionally occur in genetic males. It is a leading cause of death around the world, in part because it frequently doesn’t cause any pain or discomfort until it has spread to nearby tissue, allowing it to go unnoticed in early stages easily. 

A breast assessment includes assessing the breasts for any changes in appearance, and asking about breast symptoms like pain, redness, or unusual nipple discharge. The healthcare professional should use one hand to palpate the breast, starting in the upper quadrant near the axilla or armpit, and slowly moving across the breast in a clockwise motion. Using the three middle fingers, they should make small circles to feel into the breast tissue and then repeat on the other side. Any unusual findings may warrant further assessment, including a breast ultrasound or mammography, to assess for signs of malignancy. 

The “L” in LMNOP stands for breast lumps, which are one of the most common signs of breast cancer. Cancerous lumps are most commonly found in the upper outer quadrant of the breast and can be felt as a painless, hard, immovable mass with irregular borders. Additionally, there may be swelling or a palpable lump under the axilla, if the cancer has spread to the axillary lymph nodes. In advanced cases where the cancer has spread to the pectoral muscles, the breast may become immobile and fixed, or stuck, onto the chest wall.

One thing to note is that not all breast lumps are cancerous. Benign breast conditions cause most lumps in premenopausal females. One of the most common benign conditions is fibrocystic breast changes, which typically cause painful, lumpy breasts around the start of the menstrual cycle. Other benign breast conditions include benign tumors like fibroadenoma and intraductal papilloma, and inflammatory conditions, such as mastitis.

The “M” in LMNOP stands for mammary changes, which include any changes to the structure and appearance of the breasts, such as changes in size, shape, or skin color, as well as signs of breast asymmetry. Most commonly, warmth, redness, and breast pain are caused by mastitis, which is an inflammation of the breast tissue that is often associated with breastfeeding. However, in rare cases, they may be a sign of inflammatory breast cancer, a rare and aggressive form of cancer that usually doesn’t cause a lump or mass, so it is particularly difficult to diagnose. In particular, inflammatory breast cancer should be considered in individuals who present with signs of inflammation that have not improved after a course of antibiotics.  

The “N” in LMNOP stands for nipple changes, including an unusual nipple discharge, retraction of the nipple, or an inverted nipple. These changes often result from the invasion of the breast’s glandular tissue, which may pull on the underlying connective tissue causing retraction of the skin. 

The “O” in LMNOP stands for orange peel, or peau d’orange in French, which occurs when cancerous cells block the skin’s lymph nodes, leaving portions of the breast with a swollen and dimpled orange-peel appearance. While the peau d’orange sign is highly associated with breast cancer, it is important to remember that it might not always be present as it is often a sign of advanced cancer. 

The “P” in LMNOP stands for predisposing factors that increase the risk of breast cancer. The most common risk factors include advanced age and a family history of breast cancer, which is considered the strongest risk factor. 

Sex hormones like estrogen and progesterone stimulate breast cells to grow and divide, and exposure to them over long periods increases the risk of breast cancer. More menstrual cycles over a lifetime mean a higher exposure to these hormones, which is why factors like nulliparity, late first pregnancy, early menarche, and late menopause can increase the risk of breast cancer. Similarly, medications containing estrogen (e.g., hormone replacement therapy) can also increase the risk. 

Other predisposing factors include alcohol consumption, absence of breastfeeding, obesity in postmenopausal women, and exposure to ionizing radiation, such as from X-ray pictures and CT scans.

When performing a breast assessment, the LMNOP mnemonic can be used to remember the most important warning signs of breast cancer. It stands for breast Lumps, Mammary changes (e.g., asymmetry, tenderness, breast pain), Nipple changes (e.g., discharge, retraction, lesions), Orange peel (i.e., dimples or puckers on the skin), and Predisposing factors (e.g., family history, reproductive history, medications, radiation).