Hello,
I understand your concern, particularly because of your family history of cancer.
Firstly, most underarm lumps in young women are benign (non-cancerous). At 19 years of age, breast cancer is extremely uncommon.
Possible causes include:
Reactive lymph nodes due to minor infections or skin inflammation, including eczema.
Epidermoid cysts or blocked skin glands.
Folliculitis caused by shaving or friction.
Hidradenitis suppurativa, particularly if similar lumps repeatedly develop in the underarms.
However, the absence of pain does not confirm that a lump is harmless, and its exact cause cannot be established without examination.
Having an aunt with cancer does not automatically mean that this lump is cancerous.
Next Steps
Consult a general physician within 1â2 weeks for examination of the underarm and breasts. An ultrasound of the axilla (underarm) may be recommended to determine whether the lump represents a lymph node, cyst, or another condition. Further investigations, including biopsy, are only necessary if examination or imaging findings are suspicious. Inform your doctor about the family history, particularly which type of cancer your aunt had and her age at diagnosis. Avoid repeatedly pressing, squeezing, or massaging the lump.
Health Tips
Avoid shaving over the affected area and minimise friction until the lump has been assessed. Seek medical attention if the lump grows rapidly, becomes hard or fixed, or is accompanied by breast changes, persistent fever, unexplained weight loss, or night sweats. My recommendation: At her age, a benign cause is considerably more likely than breast cancer. Nevertheless, a persistent or unexplained underarm lump should be examined rather than ignored. An examination and, if necessary, ultrasound can provide clarity without assuming the worst. Please reassure her that seeking medical attention is a sensible precaution, not a reason to panic. Wishing her good health!