Brief Answer:
Would like to start by listing possible causes ma'am

Detailed Answer:
Hello ma'am and welcome.

Thank you for writing to us.

I have gone through your query with diligence and would like you to know that I am here to help. I am sorry to hear about your distressing presentation which can be frustrating at times, but I shall try my best to provide you with as much information as you need on the topic, cause, treatment, etc.

Let us start with the possible causes for such a presentation, and reason with each one of them to possibly pin-point the cause in your case ma'am.They are:

+Brachial plexus injury: Being an orthopedic and traumatology I get patients with such a presentation quite often, but the cause being an injury called the brachial plexus injury which takes place when the head moves away from the shoulder on the side in speaking.

+Folliculitis: Inflammation of the hair follicle on the scalp of your head or in the axillary region (i.e. the armpit) can get inflamed due to various causes (e.g. friction, shaving, waxing, etc.) and even get infected. This presentation can easily result in pain in the armpit region, especially as an abscess can develop from the infection

+Lymphangitis: Infection of the lymph nodes. You did mention the cancer, and depending on the treatment there could be a possible infection (needs to be looked into, only if your lymph nodes are still in place)

+Neuropathies: Which have been diagnosed in your case ma'am. But if at all we do narrow down to this cause, then unfortunately we can only treat this with medications and nothing else for now

+Other infections

+Benign tumors: Like for example neurofibromas that are harmless and found in the breast tissue

+Cancer (rare)

I would also like to add that the pain that you experienced under your left breast area could be due to hormonal imbalances or even the past cancer. If it is indeed the cancer (or surgery, chemo, radio), then the approach is only medications. But if it a hormonal imbalance, it is easily treatable.

I hope you find my response both helpful and informative. Please feel free to write back to me for any further clarifications, and also asking me any further details on the above mentioned causes and more details on the same.

Best wishes.

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