Follicular Lymphoma : Ki67

Comments:
With Ki-67 immunostain, low-grade follicular lymphomas (FLs) usually have a proliferation fraction of less than 20% (shown here) and high-grade FLs greater than 30%. In rare instances, low-grade FLs may have a high proliferation fraction and their prognosis is closer to Grade 3 FL than to typical Grade 1-2 FL. Ki-67 immunostaining is a useful adjunct to histologic grading in FLs. Image courtesy of: Jared Block, MD, Carolinas Pathology, Charlotte, NC