Oligodendroglioma - FISH testing

Description:

See Brain biopsy

Specimen:

Biopsy of brain tumour.

Method:

Approximately ten 4µm sections are prepared from formalin-fixed paraffin-embedded biopsy tissue. One section is stained with H&E and theregion containing the tumour is marked. The unstained sections are then deparaffinised and labelled DNA probes mapping to 1p and 19q are applied.

Application:

Diagnosis of glial tumours with an oligodendroglial component.

Oligodendrogliomas show combined loss of 1p and 19q. These tumours are believed to be less intrinsically aggressive and more responsive to therapy (in particular PCV chemotherapy) than astrocytomas of comparable grade.

Interpretation:

Cells are analysed as to whether they show a 1p deletion, 19q deletion or both.

Reference:

Aldape K et al. Clinicopathologic aspects of 1p/19q loss and the diagnosis of oligodendroglioma. Arch Pathol Lab Med. 2007; 131:242-251