I had a tumour removed and took tamoxifen for five years, but recently I’ve felt what I thought was a lump but can’t...

October 3, 2026Navis AI

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For informational purposes only

This answer was generated by AI grounded in NCCN guidelines and published medical literature. It is not medical advice. Always consult your oncologist or care team before making treatment decisions.

Sources & medical oversight

  • Built by OpenCancer’s team of physician-scientists and cancer survivors.
  • Last updated October 3, 2026. Informational only — not a substitute for your oncology team.

Question asked:

I had a tumour removed and took tamoxifen for five years, but recently I’ve felt what I thought was a lump but can’t find it every time I try to look and I feel stupid going to the doctors with a lump that I can’t find, has anyone else ever experienced this? TIA Xxxxx

You're Not Alone – And You Should Still See Your Doctor

First, please don't feel silly about this. What you're describing is actually quite common, and it's exactly the kind of thing your doctor wants to hear about – even if you can't locate the lump consistently.

Why This Happens (And Why It Matters)

Several things could explain what you're experiencing:

Benign causes (most common):

  • Hormonal changes (especially relevant since you've recently finished tamoxifen, which affects breast tissue)
  • Cysts or fluid-filled areas that feel different day-to-day
  • Scar tissue from your previous surgery, which can feel lumpy or irregular
  • Normal breast tissue that feels more prominent at certain times of the month
  • Muscle tension or inflammation in the chest wall

Why you can't always find it:

  • Breast tissue naturally changes with hormones, position, and pressure
  • What feels like a lump when lying down might feel different standing up
  • Anxiety can make you hyper-aware of normal sensations
  • Cysts can fluctuate in size

Why this still matters: Even if it's benign, your doctor needs to know because:

  • They can examine you properly and potentially do imaging (ultrasound or mammogram)
  • They can reassure you or catch something early if needed
  • They understand your history and can put findings in context
  • You'll have peace of mind

What to Do

Don't delay seeing your doctor. Here's why this is important: According to the American Cancer Society, any new breast changes should be evaluated by a healthcare professional, even if they come and go or you're uncertain about them.

When you call, you can simply say: "I've noticed what feels like a lump in my breast, though I can't always locate it. I'd like it checked given my history." That's enough – you don't need to apologize or explain why you're uncertain.

Questions to Ask Your Doctor

  1. Can you examine my breast and tell me what you feel?
  2. Do I need imaging (ultrasound or mammogram) to evaluate this?
  3. Is this likely related to finishing tamoxifen?
  4. What changes should I report in the future?
  5. How often should I have follow-up appointments given my history?

A Reassuring Note

Many breast cancer survivors experience anxiety about new sensations – this is completely normal and your doctor understands this. They'd much rather see you and reassure you than have you worry at home.

This information is for educational purposes only. Always consult your healthcare team for personalized medical advice and decisions.

Take care of yourself – reaching out to your doctor is the right move. 💙

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