RESUMO
<p><b>OBJECTIVE</b>To investigate the morphological features and immunophenotype of unspecified peripheral T cell lymphoma with distinct lymphoid follicular growth pattern.</p><p><b>METHODS</b>Three cases of peripheral T cell lymphoma with special pathohistological features were collected. Morphologic analysis and immunohistochemical staining for CD3, CD45RO, CD43, CD20, CD79a, cyclinD1, bcl-2, CD4, CD8 and S-100 were performed. PCR was used to study TCR gamma gene rearrangements.</p><p><b>RESULTS</b>The main symptoms of all the three patients with the primary sites of cervix and lower jaw. There were intermittent fever and skin rashes in the course of the disease. Morphological study showed lymphoid follicular reactive hyperplasia, mantle zone disappear, prominent infiltration of marginal zones by medium-sized tumor cells with clear cytoplasm and significant nuclear atypia. The immunophenotypic profile confirmed that they were T cell lymphomas. TCR gamma gene rearrangements were found in all the three patients.</p><p><b>CONCLUSION</b>In some unspecified peripheral T cell lymphomas, the distinct follicular growth pattern and incomplete effacement of the lymph node architecture make it necessary to differentiate them from reactive hyperplasia, marginal zone B cell lymphoma, follicular B cell lymphoma and mantle cell lymphoma.</p>