Tuesday 31 January 2012
Management and interpretation of the post-chemotherapy, operative specimen is of critical importance since it yields an
important prognostic determinant: response to pre-operative chemotherapy.
The tumour-bearing bone is cut in the longitudinal axis in the plane that will demonstrate the greatest volume of tumour.
The resulting cut-surface is sectioned and completely submitted (i.e., "mapped").
The orientation of these sections can be recorded by a number of techniques (i.e., specimen X-ray, and photocopy).
Additional "nonmapped" sections from suspect areas should also be submitted for histological analysis.
Response to therapy is recorded in terms of "tumour necrosis."
The hallmark of osteosarcoma tumour necrosis is the absence of neoplastic cells (socalled "cell drop-out") in the face of residual tumour-produced matrix.
Loose granulation tissue, fibrosis, and small numbers of inflammatory elements replace the cellular component of the tumour.
The results of this analysis is generally reported in terms of percent tumour necrosis.
- conventional osteosarcoma