Hi, Thanks for using HCM.Lymphnodes
near arm area drain region from arm, breast, chest and surrounding skin area.
Any infection in this region could cause lymphnode enlargement.
It could be a skin infection
, chest infection
, worm infestations, any chronic infection in breast or lungs.
Since its a benign enlargement get examined for any lesions.
Consult your doctor for examination and management.
Hope I answered your question. Feel free to ask me if you have any further queries.
Wish you good health. Take