Neutrophil-rich Ki-1-positive anaplastic large cell lymphoma presenting as a testicular mass.

Ki-1-positive large cell lymphoma is an uncommon subtype of lymphoma that may involve lymph nodes as well as a variety of extranodal locations. To the best of our knowledge, the occurrence of such a tumor in the testis has not been previously documented. We report a case of Ki-1-positive large cell anaplastic lymphoma presenting as a testicular mass in a 56-year old Saudi. Immunohistochemical staining revealed positive staining for Ki-1 and UCHL-1, which indicated a T-cell phenotype. This was further confirmed by polymerase chain reaction analysis, which demonstrated a monoclonal cell population with rearrangement of gamma T-cell receptor. Another interesting morphologic feature was the presence of large numbers of neutrophils throughout the tumor. Similar neutrophil-rich lymphomas have been described recently as a special subtype of Ki-1-positive anaplastic large cell lymphoma.