SITE SPECIFIC DATA ITEMS (SSDI)/ GRADE

Description

Peripheral blood involvement, summarized in “B category”, refers to the percentage of peripheral blood lymphocytes that are atypical (Sezary) cells and whether they are “Clone negative” or “Clone positive.” Mycosis fungoides is the most common type of primary cutaneous T-cell lymphoma. Sezary syndrome is a more aggressive type of primary cutaneous T-cell lymphoma in which a specific type of malignant T lymphocytes (Sezary cells) are present in the circulating blood. Staging of mycosis fungoides includes analysis of the circulating blood for Sezary cells. This analysis can be done by microscopy or flow cytometry. Results of microscopy are reported as counts of Sezary cells per cubic millimeter or the percentage of Sezary cells as a proportion of total lymphocytes. Flow cytometry looks for specific cell surface markers such as CD26. Information about peripheral blood involvement and T-cell clonality identified by polymerase chain reaction (PCR) or Southern blot analysis is combined in a “B” category unique to mycosis fungoides staging in the TNM system.

Notes

**Note 1:** **Physician statement** * Physician statement of Peripheral Blood Involvement and clonality can be used to code this data item when no other information is available * If the physician does not provide a B rating but counts or percentages of neoplastic cells, flow cytometry test results, and/or clonality test results are performed, use the appropriate code for the amount of blood involvement with “clone unknown **Note 2:** **Categories for Peripheral Blood Involvement** * B0 (no significant blood involvement) (codes 0-2) * Categorized by clonality * B1 (low blood tumor burden) (code 3-5) * Categorized by clonality * B2 (high blood tumor burden) (code 6) * Any mention of B2 puts the case into Stage IV