Table of ContentsView AllTable of ContentsDefinitionBreast Cancer ConnectionTreatmentWhen to Seek Medical CareFrequently Asked Questions
Table of ContentsView All
View All
Table of Contents
Definition
Breast Cancer Connection
Treatment
When to Seek Medical Care
Frequently Asked Questions
An armpit lump—or axillary lump—can occur as a symptom of many conditions that range from harmless to serious. It is often the result of an enlargedlymph node.
While it is a common symptom ofbreast cancer, an armpit lump is also linked withinfections,cysts,skin problems, and other factors like antiperspirants.
This article describes when an armpit lump could be a symptom of breast cancer, the causes of an armpit lump, when to see your healthcare provider, and the types of treatment used.
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What Is an Armpit Lump?
An armpit lump is an enlargement or a swollen bump that develops in the area where the underside of your arm joins your shoulder. It usually develops deep beneath the skin.
An armpit lump can vary in size, texture, and impact on arm mobility. Pain may or may not be present depending on the position of the lump.
In most cases, an armpit lump occurs as the result of a swollen lymph node, a condition calledaxillary lymphadenopathy.Lymph nodes exist under your armpit and other places throughout your body. They swell while producing immune cells to help fight infections and other foreign substances.
A swollen lymph node under your arm feels like an armpit lump when you massage or press down on your arm. The most common reason that a lymph node swells is in reaction to abacterial,viral, orfungal infectionnear your arm or elsewhere in your body.
In addition to an infection, the following factors can also make a lymph node swell:
An armpit lump can also occur due to causes unrelated to a swollen lymph node. These factors can include the following conditions:
When to Seek Emergency Care
Armpit Pain: Causes and When to Worry
Is an Armpit Lump a Symptom of Breast Cancer?
While an armpit lump can be a symptom of breast cancer, it is relatively rare for an armpit lump to be the initial sign of breast cancer. Instead, most breast cancers appear as a mass or abnormality on the breast.
To determine whether your armpit lump is linked to breast cancer, you must consult with a healthcare provider for a physical examination.
When an armpit lump occurs, there are a few reasons that it can be a symptom of breast cancer. These factors include:
Lymph Node-Positive Breast Cancer
Treatment of an Armpit Lump
If cancer is suspected, your healthcare provider will want to confirm the diagnosis. Treatment of the lump is based on a detailed medical history, including the duration of the lump, the condition of the lump, and your history of breast cancer or any other cancer.
Your healthcare provider will likely request certain medical tests to confirm your diagnosis. These tests can include:
If cancer is detected, treatment may include:
When to See Your Healthcare Provider
You may notice an armpit lump because it is annoying. It can also feel like a raised pea during abreast self-exam (BSE). It is usually safe to wait a few days to see how it progresses. If the armpit lump occurs as a reaction to inflammation or another harmless cause, it may disappear on its own without treatment.
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Summary
An armpit lump, or axillary lump, can occur as a symptom of breast cancer but is more likely to happen as the result of an enlarged lymph node or other problem. In many cases, an armpit lump occurs as the result of an infection, cyst, skin problem, or an allergy to body care products.
A Word From Verywell
It can be frightening to notice an armpit lump. While it’s likely a harmless bump, it’s normal to worry that the lump might be a sign of breast cancer. Getting an early and accurate diagnosis of the lump is the best way to ease your concerns and get the treatment you need. This is especially important if the lump proves to be malignant.
Dealing with breast cancer can be an overwhelming experience. You may benefit from speaking to others who have gone through the same experience. Consider joining anonline or in-person support groupfor people who havemetastatic breast cancer. With the right support and treatment, you can achieve optimal results.
While most of your breast sits on top of your chest muscle, some breast tissue extends from the edge of your sternum out to the underarm. Lumps can occur when there is a buildup of breast milk due to a blocked duct or engorgement in the mammary glands under your arm.Learn MoreThe Anatomy of the Mammary Glands
While most of your breast sits on top of your chest muscle, some breast tissue extends from the edge of your sternum out to the underarm. Lumps can occur when there is a buildup of breast milk due to a blocked duct or engorgement in the mammary glands under your arm.
Learn MoreThe Anatomy of the Mammary Glands
Learn MoreBenign and Malignant Breast Lumps
Hidradenitis suppurativa, also known as acne inversa, is a chronic, noncontagious skin condition that causes lumps deep under your skin. The lumps usually develop in areas where two areas of skin naturally rub against each other, like the armpits or inner thighs. The lumps can be painful and leak fluid. Without treatment, nonhealing wounds can result.Learn MoreHidradenitis Suppurativa (Acne Inversa) Overview
Hidradenitis suppurativa, also known as acne inversa, is a chronic, noncontagious skin condition that causes lumps deep under your skin. The lumps usually develop in areas where two areas of skin naturally rub against each other, like the armpits or inner thighs. The lumps can be painful and leak fluid. Without treatment, nonhealing wounds can result.
Learn MoreHidradenitis Suppurativa (Acne Inversa) Overview
9 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Dana-Farber Cancer Institute.Should I worry about a lump under the armpit?MedlinePlus.Swollen lymph nodes.Zakaria S, Johnson R, Pockaj BA, Degnim AC.Breast cancer presenting as unilateral arm edema.J Gen Intern Med. 2007;22(5):675-676. doi:10.1007/s11606-006-0077-0Susan G. Komen.Lymph node status.DeFilippis EM, Arleo EK.The abcs of accessory breast tissue: basic information every radiologist should know.American Journal of Roentgenology. 2014;202(5):1157-1162. doi:10.2214/AJR.13.10930Johns Hopkins Medicine.Anatomy & physiology of the breast.Ampil F, Caldito G, Henderson B, et al.Carcinoma of the axillary tail of spence: a case series.Anticancer Research. 2012;32(9):4057-4059.Fribbens C, O’leary B, Kilburn L, et al.Plasma ESR1 mutations and the treatment of estrogen receptor-positive advanced breast cancer.J Clin Oncol. 2016;34(25):2961-8. doi:10.1200/JCO.2016.67.3061American Academy of Dermatology Association.Hidradenitis suppurativa.
9 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Dana-Farber Cancer Institute.Should I worry about a lump under the armpit?MedlinePlus.Swollen lymph nodes.Zakaria S, Johnson R, Pockaj BA, Degnim AC.Breast cancer presenting as unilateral arm edema.J Gen Intern Med. 2007;22(5):675-676. doi:10.1007/s11606-006-0077-0Susan G. Komen.Lymph node status.DeFilippis EM, Arleo EK.The abcs of accessory breast tissue: basic information every radiologist should know.American Journal of Roentgenology. 2014;202(5):1157-1162. doi:10.2214/AJR.13.10930Johns Hopkins Medicine.Anatomy & physiology of the breast.Ampil F, Caldito G, Henderson B, et al.Carcinoma of the axillary tail of spence: a case series.Anticancer Research. 2012;32(9):4057-4059.Fribbens C, O’leary B, Kilburn L, et al.Plasma ESR1 mutations and the treatment of estrogen receptor-positive advanced breast cancer.J Clin Oncol. 2016;34(25):2961-8. doi:10.1200/JCO.2016.67.3061American Academy of Dermatology Association.Hidradenitis suppurativa.
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Dana-Farber Cancer Institute.Should I worry about a lump under the armpit?MedlinePlus.Swollen lymph nodes.Zakaria S, Johnson R, Pockaj BA, Degnim AC.Breast cancer presenting as unilateral arm edema.J Gen Intern Med. 2007;22(5):675-676. doi:10.1007/s11606-006-0077-0Susan G. Komen.Lymph node status.DeFilippis EM, Arleo EK.The abcs of accessory breast tissue: basic information every radiologist should know.American Journal of Roentgenology. 2014;202(5):1157-1162. doi:10.2214/AJR.13.10930Johns Hopkins Medicine.Anatomy & physiology of the breast.Ampil F, Caldito G, Henderson B, et al.Carcinoma of the axillary tail of spence: a case series.Anticancer Research. 2012;32(9):4057-4059.Fribbens C, O’leary B, Kilburn L, et al.Plasma ESR1 mutations and the treatment of estrogen receptor-positive advanced breast cancer.J Clin Oncol. 2016;34(25):2961-8. doi:10.1200/JCO.2016.67.3061American Academy of Dermatology Association.Hidradenitis suppurativa.
Dana-Farber Cancer Institute.Should I worry about a lump under the armpit?
MedlinePlus.Swollen lymph nodes.
Zakaria S, Johnson R, Pockaj BA, Degnim AC.Breast cancer presenting as unilateral arm edema.J Gen Intern Med. 2007;22(5):675-676. doi:10.1007/s11606-006-0077-0
Susan G. Komen.Lymph node status.
DeFilippis EM, Arleo EK.The abcs of accessory breast tissue: basic information every radiologist should know.American Journal of Roentgenology. 2014;202(5):1157-1162. doi:10.2214/AJR.13.10930
Johns Hopkins Medicine.Anatomy & physiology of the breast.
Ampil F, Caldito G, Henderson B, et al.Carcinoma of the axillary tail of spence: a case series.Anticancer Research. 2012;32(9):4057-4059.
Fribbens C, O’leary B, Kilburn L, et al.Plasma ESR1 mutations and the treatment of estrogen receptor-positive advanced breast cancer.J Clin Oncol. 2016;34(25):2961-8. doi:10.1200/JCO.2016.67.3061
American Academy of Dermatology Association.Hidradenitis suppurativa.
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