Molecular Pathology Laboratory Network

F T12

+12, CEP 12

Chronic Lymphocytic Leukemia (CLL)

Fluorescence in situ Hybridization (FISH)

88367 x1 - Morphometric analysis, in situ hybridization, automated
88368 x1 - Morphometric analysis, in situ hybridization, manual

3 days

• 2.0 mL (min. 1.0 mL) peripheral blood in sodium heparin preferred, EDTA accepted
• 1.0 mL (min. 0.5 mL) bone marrow in sodium heparin preferred, EDTA accepted
• 5 mm^3 fresh tissue in MPLN RPMI media
• 3.0 mL (min. 2.0 mL) FNA in MPLN RPMI media
• 10% neutral buffered formalin fixed paraffin embedded tissue

• Peripheral blood and bone marrow stable at 18-25°C for 72 hours
• Fresh tissue or FNA stable at 2-8°C for 72 hours

• Whole blood and bone marrow, ship ambient
• Fresh tissue, FNA or paraffin embedded tissue, ship in a Styrofoam container with a cool/refrigerated pack (Do not allow cool pack to directly contact sample.)

Clotted specimen; Specimen exposed to extreme temperature; Anticoagulant toxic to cells; Insufficient number of cells; Improper fixative

In a normal cell, the expected pattern is the two green signal pattern. In a hybridized abnormal cell containing a trisomy of chromosome 12, a three green signal pattern is detected.

Trisomy 12 is among the more common recurring chromosomal defects in chronic lymphocytic leukemia (CLL). It has been reported in 15–30% of cases and is correlated with atypical morphology. FISH can detect this trisomy in either interphase or metaphase cells.