Hello! Welcome to HCM! I carefully read your question and would explain that your lumps below the armpits may be lymph nodes, related to inflammation or a tumor. Do you have fever, cough or other symptoms. I recommend consulting with your GP for a careful physical exam and some tests: - chest X ray study for your lungs - a Doppler ultrasound of the soft tissues on the armpits and breasts, to exclude possible lesions in your breasts. - lab blood tests (complete blood count, inflammation tests) A chest CT scan followed by a brain CT scan may be needed if suspicions of possible chest lesions (tumoral) are raised. Hope to have been helpful! Best wishes, Dr. Aida