Ay, I haven't personally encountered that sa anak ko, pero definitely kailangan na tingnan ng doctor yan, bukol sa likod ng ulo, lalo na kung may sakit or discomfort, hindi dapat i-ignore kahit gaano kaliit, kaya good call na magpa-checkup na kayo agad. A few of us moms have had random lumps or bumps on our babies that turned out to be nothing serious, pero some needed attention, so better safe talaga. Sana normal lang yan at mabilis lang ma-address ng pedia ninyo!