What Causes Thick Mass Protruding Out Of Neck And Chest?

I am 33 years old,got married before 4 years,have two daughters.thick mass(spherical shape,mustard size) is protruding out from my skins especially in neck,chest and abdomen,its growing in numbers day by day.I am afraid since in my family my uncle,two cousins died of cancer.Pls clear my doubt what could it be and its treatment.