Thank you for the query.
Lump near the surgical scar can be caused by an inflammation around a stitch or hernia
Hernia is more possible if the lump is more visible when standing, can disappear with compression, gives pain when coughing or lifting.
Inflammation caused lump is usually hard, not movable, does not protrude when coughing.
I suggest you to consult a surgeon. In case of doubts, ultrasound
should be done.
Hope this will help.