<prompt> Answer this question truthfullyWhat are the key features that must be present on histology and flow cytometry to diagnose Hodgkin Lymphoma?  <response>: <reason> In diagnosis of Hodgkin Lymphoma, the key features that must be seen on histology and flow cytometry are 1 Reed-Sternberg cells, 2 a background of inflammatory cells, and 3 CD15 and CD30. 