DNA cell cycle analysis is performed on a flow cytometer and can provide prognostic information for patients with several types of neoplasms. For instance in acute lymphoblastic leukemia, hyperdiploid (more than normal number of chromosomes) are associated with a good prognosis and hypodiploid (less than normal number of chromosomes) ALL has been associated with a poor prognosis. In lymphomas, DNA cell cycle analysis is not only useful for prognostic information to stratify non-Hodgkin lymphomas into high and low risk groups, but is also helpful in diagnosis. Reactive lymphoid proliferations do not demonstrate abnormal DNA ploidy (reflective of an increase or decrease in chromosome number).

In solid tumors, DNA cell cycle analysis generally provides prognostic information. The following are neoplasms where DNA cell cycle analysis has been judged to be beneficial.

• Breast carcinoma Aneuploidy and a high S phase indicates a prognosis with a high risk of relapse and a shorter survival.
• Colon carcinoma Aneuploidy and a high S phase indicates a prognosis of decreased survival.
• Ovarian carcinoma Aneuploidy indicates a prognosis of decreased survival.
• Bladder carcinoma Aneuploidy indicates a prognosis with greater risk for tumor progression.

An alternate methodology for DNA cell cycle determination utilizes an instrument which analyzes a microscopic image of an individual cell. The pathologist selects the cell population to be analyzed by the technologist looking specifically for morphologic features of tumor cells. Data for each cell selected is stored by the computer in a designated file. Information obtained includes cell area, shape density, and class. Video 4. This methodology is more costly to perform when compared to flow cytometry since it is more labor intensive. Image analysis should be performed when flow cytometry of a confirmed malignant histologic specimen is unremarkable or in distinct situations where insufficient specimen is available to perform flow cytometry