Primary non-Hodgkin's lymphoma of the tongue: a diagnostic dilemma of unusual case presentation.

Primary non-Hodgkin's lymphoma of the tongue is extremely uncommon, which makes its diagnosis quite challenging. A panel of 11 markers is used based on morphological differential diagnosis to elucidate the lymphoma subtype. A case of 43-year-old Egyptian man suffering from nodular mass on the right side of the tongue of 4 months duration is presented. No cervical lymphadenopathy was detected. No abdominal organomegaly was noted. The histological evaluation of incisional biopsy revealed a sheet of pleomorphic lymphoid cells with abnormal mitotic figures. A large number of histiocytes were infiltrating the lymphoid cellular sheet. The results of immunophenotyping were extranodal T-cell lymphoma. A proper immunohistochemical workup is crucial for the correct diagnosis and proper management.