Discovering a lump in the armpit (axillary mass) can cause concern. The axilla contains many structures, including fat, skin, and lymph nodes, and any new lump requires professional evaluation. Most masses are benign, often resulting from swollen lymph nodes due to localized infection or irritation. However, since the armpit is a location where certain cancers, such as breast cancer or lymphoma, can first present, following a clear medical pathway is important. This pathway begins with an initial assessment and moves toward specialized care and definitive diagnosis.
The Essential First Step: Primary Care Assessment
A Primary Care Provider (PCP) should be the first point of contact for an unexplained armpit lump. The PCP conducts a thorough initial assessment to determine the likely cause and urgency. This involves taking a detailed medical history, noting when the lump was first noticed and if it has changed in size or texture.
The physical examination is a core component of this first visit, where the doctor will gently palpate the lump to assess its characteristics. They note specific details such as the lump’s size and consistency. Consistency is important: soft and mobile lumps are often benign, while hard and fixed lumps are potentially more concerning. The PCP also checks for associated symptoms, including fever, redness, discharge, or unexplained weight loss, which can point toward infection or a systemic issue.
If the lump is painful, red, and warm, it may indicate an acute infection or an abscess requiring immediate treatment like drainage or antibiotics. If lumps do not resolve after a few weeks, increase in size, or present with other concerning features, the PCP initiates the referral process for further investigation. This initial triage guides patients toward the correct specialist if necessary.
Specialized Care: When and Which Doctor to See
The nature of the lump, determined by the initial examination, dictates the type of specialist referral. The most common specialists involved are the General Surgeon, the Dermatologist, and the Oncologist/Hematologist.
General Surgeon
A General Surgeon or specialized Breast Surgeon is often consulted if the lump is solid, persistent, or suspected to involve deeper structures like lymph nodes or accessory breast tissue. Surgeons are required when the mass needs to be surgically removed for diagnosis or treatment, or when advanced imaging points toward a complex internal lesion.
Dermatologist
A Dermatologist is the appropriate referral if the lump appears superficial and originates in the skin or subcutaneous tissue. Conditions common in the armpit, such as cysts, lipomas, or abscesses, fall under the Dermatologist’s expertise. This is especially true if drainage or simple excision is needed.
Oncologist or Hematologist
If the initial workup or biopsy results point toward a systemic issue or malignancy, the patient may be referred to an Oncologist or a Hematologist. An Oncologist specializes in treating cancer, while a Hematologist deals with disorders of the blood, including lymphomas. This specialized pathway ensures treatment is managed by a physician with the highest level of specific expertise.
Confirming the Diagnosis: Key Procedures
Once a referral is made, specialists rely on specific procedures to achieve a definitive diagnosis. Ultrasound is typically the most common first-line imaging test used to evaluate an axillary mass. This non-invasive procedure uses sound waves to quickly determine if the lump is solid tissue or a fluid-filled cyst. It also allows the radiologist to assess the morphology of any enlarged lymph nodes.
If the lump is located in the axillary tail (the portion of breast tissue that extends into the armpit) or if underlying breast pathology is suspected, a Diagnostic Mammogram may be ordered to image the entire breast tissue.
The definitive way to confirm the composition of a suspicious mass is through a biopsy, where a tissue sample is collected for microscopic examination by a pathologist. Two primary types of needle biopsies are used: Fine-Needle Aspiration (FNA), which uses a very thin needle to collect cells or fluid, and Core Needle Biopsy (CNB), which uses a larger needle to remove a small cylinder of tissue. The biopsy is often guided by ultrasound to ensure the needle accurately targets the suspicious area within the lump.