Thank you for your question.
I am Dr. Su S. and I will try my best to help you.
I am sorry for her symptoms.
The lump on the chest can due to a few probabilities.
Hard lump can be fibroma, osteoma.
Prominent joint of rib with cartilage can appear as lump in this area.
Dermoid cyst, enlarged lymph node, neurofibroma can be possible here.
But they are firm in nature.
They are all benign condition.
This is unlikely to be related with enlarged lymph nodes in the abdomen.
Tomorrow doctor will examine her physically and confirm the nature of the lump.
I hope this information will be helpful.
If you have any query, please feel free to ask.
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Wish her healthy life.