Certain lymphoma types are characterized by recurring genetic translocations. Detection of these translocations enables confirmation of a suspected diagnosis and provides a genetic marker which can be subsequently monitored and followed. Rapid and reliable identification of these molecular rearrangements is a key component in the workup of lymphoma. While conventional cytogenetics may be a useful tool in this regard, fluorescence in situ hybridization (FISH) offers additional advantages including the ability to use formalin-fixed tissues, no requirement for dividing cells, ability to score many cells, improved sensitivity, and faster turnaround time for results.