My Great Dane has a large lump on his torso. Is it a serious concern?

Thank you for contacting Petco Pet Education Center, formerly Petcoach with your question about Brody. Given his age and the fact that he's a giant breed dog (who typically do not live as long as other breeds of dogs), there is a chance this could be a malignant growth. It could also be a cyst, lipoma, or benign growth. Any suspicious lumps should be examined by the vet. The vet can perform a test called a fine needle aspirate on it. To do this, the vet sticks a small needle into the lump to get a sample of its cells, and examines the cells on a slide under a microscope. It's usually painless to the animal, and relatively quick to perform. Once the cause of the lump is diagnosed, the vet can discuss treatment options if needed. I would try to get into his vet to get this checked out. I hope this helps!