Case Presentation

1. Case Presentation • December 19, 2007

2. 21 y.o. male • CC: Right leg pain • HPI: 1 year ago had surgery for a “tumor” on right leg. “Replaced my shin bone. But I don’t remember what they called it.”

3. PMH/PSH: as above • NKDA • Meds: None • SHx: denies ETOH, TOB or illicit drug use, recently discharged from the Navy, swims for exercise, BA in nursing but currently on disability • FHx: N/C

4. Pertinent Positives: • Well-healed scars on right shin, including skin graft site mid-shaft • Intact neurovascular exam • Imaging:

6. Plain XR

7. Allograft Nonunion • 8 – 17% reported • Lack of host-donor junction @ 1 year • Union = gap obliterated or bridging bone @ 3 or greater cortices on AP and Lateral imaging • Worse outcomes if: • Adjuvant chemotherapy • Adjuvant radiation • Infection – usually occurs in 1st year • Fracture – usually occurs in first 3 years • Original disease stage II or III (MTS) • Allograft is part of arthrodesis procedure

8. Allograft Nonunion • Retrospective review 945 allograft patients: • 163 nonunion (17.3%) • No chemo, no XRT 11.3% • XRT only 18% • Chemo 27% • 162 revised: • 47% required further procedures for nonunion • 49 ultimate failures required metallic prosthesis, replacement of allograft or amputation Menken HJ et al, CORR 2001; 382: 87-98.

9. Allograft Nonunion • 718 patients observed greater than 2 years: • 75% retained and successful for >20 years • 17% nonunion • 11% infection • 19% fracture • 6% unstable joint • Of the failed allografts: • >85% of the failures due to infection, fracture, recurrence of primary tumor • Susceptibility to infection primarily in 1st year • Susceptibility to fracture in first 3 years Menken HJ et al.; CORR, 1996; 324:86-97.

13. Adamantinoma • 0.4 - 1% of all primary bone tumors • 2nd & 3rd decade; range 3-86 yrs • Pain, swelling in adolescent or young adult • 85 – 90% tibial shaft • 10% of these ipsilateral fibula • Femur, humerus, ulna, radius, hands/feet

14. Adamantinoma • Mets in 12-29% • Lung, bone, regional lymph nodes • Mortality 13-18% • Survival with metastatic disease ~ 13 yrs • Risk factors: • Intra-lesional treatment • Male • Short duration of symptoms • Young age on presentation (<20 yrs) • Lack of squamous differentiation of tumor

15. Adamantinoma - XR • Eccentric, cortical, diaphyseal, long bone • Sclerotic edge slowly growing lesion • Slight expansion of cortex with thinning • Cystic or multiloculated appearance • Lack of periosteal reaction, even in presence of extensive cortical destruction • Two most characteristic features: • Location in tibia • Intracortical involvement

16. Adamantinoma • MRI: • T1 – isointense, enhances with gadolinium • T2 – hyper-intense

17. Histology -Basiloid cells, pseudoglandular pattern and peripheral palisading, characteristic of an adamantinoma

18. MTS System • Stage Grade* Site† Metastasis‡ • I A G1 T1 M0 • B G1 T2 M0 • II A G2 T1 M0 • B G2 T2 M0 • III G1 or G2 T1 or T2 M1 • *G1 = low grade and G2 = high grade. • †T1 = intracompartmental and T2 = extracompartmental. • ‡M0 = no regional or distant metastasis and M1 = regional or distant metastasis.

19. AJCC Staging System