Pathology: osteofibrous dysplasia

Osteofibrous dysplasia

• Spindle-stellate cells with vague storiform pattern

• Pale eosinophilic cytoplasm

• Monomorphic ovoid nuclei; inconspicuous mitotic activity

• Irregular woven bone trabeculae lined by osteoblasts

• Delicate thin-walled vasculature; occasional osteoclasts

• IHC: keratin (AE1/AE3), p63

In contrast to the osteofibrous dysplasia-like variant of adamantinoma, only single scattered keratin / p63 positivity is present

Osteofibrous dysplasia

• Spindle-polygonal cells with storiform pattern

• Pale eosinophilic cytoplasm

• Monomorphic ovoid nuclei; inconspicuous mitotic activity

• Plump and irregular woven bone trabeculae lined by osteoblasts

• Delicate thin-walled vasculature; occasional osteoclasts