26000 1p19q Deletion in Gliomas, FISH, Tissue (GLIOF)

Aids in diagnosing oligodendroglioma tumors and predicting the response of an oligodendroglioma to therapy

May be useful in tumors with a complex "hybrid" morphology requiring differentiation from pure astrocytomas to support the presence of oligodendroglial differentiation/lineage

Indicated when a diagnosis of oligodendroglioma, both low-grade World Health Organization (WHO, grade II) and anaplastic (WHO, grade III) is rendered

Strongly recommended when a diagnosis of mixed oligoastrocytomas is rendered

Submit a formalin-fixed, paraffin-embedded (FFPE) tumor tissue block. Blocks prepared with alternative fixation methods may be acceptable; provide fixation method used.

OR

Six consecutive, unstained, 5 micron-thick sections placed on positively charged slides, and 1 hematoxylin and eosin-stained slide.

A reason for referral and pathology report are required in order for testing to be performed. Send information with specimen. Acceptable pathology reports include working drafts, preliminary pathology or surgical pathology reports.

The presence of short arm of chromosome 1(1p) deletion and combined 1p and long arm of chromosome 19 deletion supports a diagnosis of oligodendroglioma may indicate that the patient may respond to chemotherapy and radiation therapy.

The presence of gain of chromosome 19 supports a diagnosis of high-grade astrocytoma (glioblastoma multiforme).

A negative result does not exclude a diagnosis of oligodendroglioma or high-grade astrocytoma.