2D sagittal CT slice and corresponding 3D Shaded Surface Display reconstruction through the humerus of a Sperm Whale (Physeter macrocephalus). Dissection revealed numerous bone lesions throughout the skull and axial skeleton. CT and histology demonstrated erosion of articular cartilage and outgrowths of marginal osteophytes (arrow) consistent with chronic osteoarthritis and a benign cartilaginous neoplasm, covered with a rim of proliferating cartilage cells (arrows) typical of osteochondroma (related report). Specimen courtesy of Cape Cod Stranding Network (CCSN/IFAW).