Trying out a few programs today (thank you #PathTwitter for all the great resources!), and now I can post gross pictures! Primary bone tumor from a 17 year old male. Can anyone venture a guess on the diagnosis? https://abs.twimg.com/emoji/v2/... draggable="false" alt="🤓" title="Nerd-Gesicht" aria-label="Emoji: Nerd-Gesicht"> #Grossognosis #BSTPath

Pointers on typical gross findings of osteosarcoma!
https://abs.twimg.com/emoji/v2/... draggable="false" alt="📌" title="Reißzwecke" aria-label="Emoji: Reißzwecke">Usually metaphyseal in long bones (90%)
https://abs.twimg.com/emoji/v2/... draggable="false" alt="📌" title="Reißzwecke" aria-label="Emoji: Reißzwecke">Tumor frequently breaks through the cortex and lifts the periosteum,
https://abs.twimg.com/emoji/v2/... draggable="false" alt="📌" title="Reißzwecke" aria-label="Emoji: Reißzwecke">Codman triangle: triangular shadow between the cortex and raised ends of periosteum

Histopathology of osteosarcoma:
https://abs.twimg.com/emoji/v2/... draggable="false" alt="📌" title="Reißzwecke" aria-label="Emoji: Reißzwecke">Essential to the diagnosis: bone production (osteoid formation) by the tumor cells; lace-like pattern
https://abs.twimg.com/emoji/v2/... draggable="false" alt="📌" title="Reißzwecke" aria-label="Emoji: Reißzwecke"> High grade: neoplastic cells with severe anaplasia and pleomorphism, abundant (and atypical) mitotic figures