Metachronous extranodal natural killer/T-cell lymphoma of nasal type and primary testicular lymphoma

We report a rare case of metachronous lymphoma with two distinct cell lineages in a 75-year-old man. The patient complained about having nasal obstruction for 2 years and extranodal natural killer (NK)/T-cell lymphoma of the nasal type was diagnosed from a biopsy. The immunohistochemical staining for CD56 and in situ hybridization for Epstein-Barr virus (EBV)–encoded small RNA (EBER-ISH) were positive and the tumor cells were negative for CD20. After 13 months of concurrent chemoradiotherapy, the patient presented with swelling of the left testis. Positron emission tomography scan detected an abnormal uptake in the testis. A diffuse large B-cell lymphoma, not otherwise specified, was diagnosed from subsequent radical orchiectomy. The immunohistochemical staining revealed to be positive for CD20, BCL2, BCL6, and MYC and negative for CD10 and EBER-ISH.