Extranodal peripheral T-cell lymphoma with angiocentric growth pattern andEpstein-Barr viral DNA associated affecting paratesticular soft tissue

Peripheral T-cell lymphomas are uncommon, accounting for only 10% to 15% of all non-Hodgkin lymphomas and their classification has been controversial. We report a case of peripheral T-cell lymphoma with angiocentric growth pa ttern which presented as a paratesticular tumoral nodule in a 47-year-old-m an. Formalin-fixed paraffin-embedded samples from the paratesticular tumor and non-infiltrated adjacent tissue were submitted to histological, immunoh istochemical, polymerase chain reaction (PCR)-based and in situ hybridizati on analysis. Histopathologically, there was a lymphomatous infiltrate in th e paratesticular soft tissue, composed of a variable mixture of medium-size d to large cells with large cytoplasm and irregular-shaped nuclei, together with blood vessel destruction, necrosis and karyorrhexis. Immunohistochemi cal study revealed a high p53 expression in neoplastic cells that showed T cytotoxic immunophenotype, failing to express the natural killer (NK)-cell antigen CD56. A monoclonal rearrangement of the T-cell receptor (TCR) gamma gene by a PCR technique was demonstrated. Type-A Epstein-Barr Virus (EBV) DNA was detected by PCR-based analysis. A combined in situ hybridization an d immunohistochemical study revealed that most cells labeled positive for E BV RNA showed immunostaining with the CD45RO antibody. Based on the above r esults, the case reported was classified as extranodal peripheral T-cell ly mphoma with cytotoxic phenotype and EBV associated. The present case does n ot fit neatly into any of the specific types of peripheral T-cell lymphomas of the REAL classification, so a diagnosis of peripheral T-cell lymphoma u nspecified was made.