Histopathology:
MACROSCOPIC DESCRIPTION: A segment of bone with a base measuring 55 mm in length x 22 mm in diameter with a protuberant pale white glistening tumour nodule 35x30x up to 32 mm in thickness. Base inked blue. Sectioning reveals a cartilage cap up to 10 mm in thickness.
MICROSCOPIC DESCRIPTION: Sections show an osteochondroma composed of lamella bone forming a short, broad stalk covered by a 1 cm cartilaginous cap consisting of hyaline cartilage. Chondrocytes demonstrate endochondral ossification with normal growth maturation. No chondrocyte hypercellularity, atypia, mitoses or necrosis are seen. There is no invasion of bone or adjacent soft tissues. There is no evidence of malignancy.
DIAGNOSIS: Osteochondroma.