Thank you for the query.
This is unlikely for this lump to be associated with GERD. It is very hard for the lump inside the chest or abdomen to get through the tissues and be palpated outside. It is possible only for very large tumors, but such would give plenty of other symptoms.
So this lump can be sebaceus cyst or lymphoma
. Both are benign and can be left without surgery.
IF you want to be sure, soft tissues ultrasound
should be performed.
If it is about GERD, it should be diagnosed with upper GI endoscopy
to make sure there is no peptic ulcer
, cancer and if there is Helicobacter Pylori infection
. Without is, such symptoms can be hardly treatable.
Hope this will help.