T-cell/Histiocyte-rich large B-cell lymphoma (THRLBCL) is a rare pathology, uncommon in children population and the few cases reported, had wide range clinical presentations, including advanced stage, extranodal involvement and bad prognosis. Authors report a case of a 16-year-old male patient with no medical history, who presented a single left axillary adenopathy. T-cell/Histiocyte-rich large B-cell lymphoma was diagnosed by immunohistochemistry and was classified good prognosis. A RCHOP-based chemotherapy was performed with good progress. Authors hope to contribute to the literature on THRLBCL and draw the attention of practitioners to its occurrence in the pediatric population.