What are the symptoms of sebaceous cysts and tumour?

Mass growing : You will feel a lump growing under skin. Sometimes a white discharge is noted.

Skin lump, infection: A sebaceous cyst is a firm round nodule deep in the skin which results from accumulated oil (or sebum). This is usually due to a minor injury to the skin. The cyst gradually gets larger and then, radomly, can become infected when germs find their way in and multiply in the old oil. This causes pain, redness and rapid enlargement and, eventually, rupture. Removal is best if definitely enlarging.