When doctors use the term tumor they are talking generically and not about the size of the lesion. A mass usually refers to a lump which is at least 20 mm (0.787 inches) in diameter at its widest point, while a nodule is less than 20 mm at its widest point.
But how big a spiral can you get? Our Milky Way galaxy is pretty beefy, one of the bigger spiral galaxies in the Universe. Itâs roughly 100,000 light-years across, or a quintillion kilometers. Thatâs a lot of kilometers. Donât go bragging to your friends just yet though.
We are seeing them just 600 million years after the Universe's birth in the Big Bang. Galaxy clusters are the largest structures in the Universe, comprising hundreds to thousands of galaxies bound together by gravity.