A sebaceous cyst on the nipple seems extremely unlikely. Sebum is usually fairly oily and sometimes even fairly thick. This is not what was described. This sounds like the typical milk cyst. I usually open it with a sterile needle (the mother can do this) when it develops, squeeze out any thickened milk, and then treat with Kenacomb ointment for a couple of weeks (after every feeding, do not wipe or wash off). I think this prevents it from coming back, but I'm not sure. In the US, a combination of Mycolog and Mupirocin ointments would be a good, maybe better, substitute. I would advise the mother to stay away from an excision of the lesion. Jack Newman, MD, FRCPC