giant cell-rich lesions of bone

Digital cases

 Case 86 (HPC:86): Peripheral giant cell reparative granuloma of bones (PGCRG)
 Case 157 (HPC:157) : Giant cell-rich osteoblastic osteosarcoma
 Case 177 (HPC:177): Peripheral giant cell reparative granuloma of bones (PGCRG)

Differential diagnosis

 giant cell tumor of bone (GCTB)
 giant cell reparative granuloma (GCRG)
 aneurysmal bone cyst (ABC)
 giant cell-rich osteosarcomas

These lesions may have overlapping clinical, radiologic, and histopathologic features. In fact, GCRG and solid ABC are currently differentiated solely based on skeletal location.

Cytogenetics

Cytogenetic studies have reported that telomeric associations are present in the majority of giant cell tumors of bone (GCTB), whereas translocations involving 16q22 and/or 17p13 are characteristic of ABCs.

Karyotype of GCRG revealed a reciprocal translocation, t(X;4)(q22;q31.3), inv(2)(p13q21) (17527082) and t(inv2;11)(q21;q13), t(2;10)(q23;q24) (17527082).

A subset of GCRGs may be neoplastic and that these lesions differ cytogenetically from classic giant cell tumors of bone or solid ABC, although the latter entity is otherwise indistinguishable from reparative granuloma.

References

 Novel karyotypes in giant cell-rich lesions of bone. Gleason BC, Kleinman PK, Debelenko LV, Rahbar R, Gebhardt MC, Perez-Atayde AR. Am J Surg Pathol. 2007 Jun;31(6):926-32. PMID: 17527082