Details

1p and 19q Detection Assay by FISH

Specimen Collection Criteria

Collect (preferred specimen): Formalin-fixed, paraffin-embedded block with corresponding H&E slide. Tissue should be well fixed and well processed. Tissue size should be 0.2 cm x 0.2 cm x 0.2 cm. 
Also acceptable: One H&E slide plus 3 unstained tissue sections cut at 4 cm thick and placed on charged slides. Oven dry at 60°C for 1 hour. Unbaked or air-dried slides are acceptable. Tissue adherence cannot be guaranteed for sections placed on plain glass slides. Send all slides within 6 weeks of cutting.

Specimen must be accompanied by a completed requistion and must contain the patient name, date of birth, collection date, ordering physician, and source of specimen. Provide pathology report with each specimen, including type of fixative and duration of fixation (if known).

Physician Office/Drawsite Specimen Preparation

Maintain paraffin-embedded tissue or slides at room temperature (20-26°C or 68-78.8°F) until transport. 

Preparation for Courier Transport

Transport: Paraffin-embedded tissue or slides at room temperature (20-26°C or 68-78.8°F).

Rejection Criteria

  • Tissue in fixatives other than 10% formalin.
  • Improper labeling, inadequate information.
  • Decalcified specimens are not acceptable.

Performed

Monday - Friday.
Results available in 7 business days.

Reference Range

Neoplasms containing a 1p36/1q25 gene ration less than 0.88 are considered to be deleted for 1p36.
Neoplasms containing a 19q13/19p13 gene ration less than 0.74 are considered to be deleted for 19q13. 

Test Methodology

Fluorescent in situ hybridization.

Interpretation

Hybridized sections are reviewd on a fluorescence microscope by a trained Molecular Technologist. The copy number status of 1p36 and of 19q13 is determined using fluorescent microscopy. Results are reviewed by the pathologist who will provide an interpretive report. 

Clinical Utility

Malignant gliomas are the most common type of primary brain tumor. They have been histologically classified as astrocytomas, oligodendrogliomas, and mixed gliomas. Demonstration of combined loss of the short arm of chromosome1 (1p) and the long arm of chromosome of 19 (19q) in cases of oligodendrogliomas help identify patients with increased sensitivity to treatments. These patients also have a more favorable prognosis. 

Reference

Burger PC et al. Losses of chromosomal arms 1p and 19q in the diagnosis of oligodendroglioma: a study of paraffin-embedded sections. Mod Pathol 2001:14(9): 842-853.

CPT Code

88366x2, 88374x2.

Last Updated

7/11/2019