The right portion of my navel has a sac filled with semi-solid material and its size gradually increases from the past 5 years.what does it indicates?

Cyst : It is most likely an epidermal cyst. Not worth a trip to the hospital, but it's worth pointing out the next time you see your doctor or a dermatologist to confirm that it is indeed that. Of course, if it starts to grow or bleed or change color, have it looked at right away.

Cyst: See a general surgeon for excision of the umbilical cyst. These are benign, but annoying!