The gastrointestinal tract is the most common site for extranodal non Hodgkin's lymphomas with B cell lymphomas being the most commonly encountered. The clinical symptoms and endoscopic findings are non-specific, however, the first obtained biopsy establishes the diagnosis in more than three quarters of the patients. Recognizing early lesions and differentiating lymphomas from hyperplastic reactive lesions may be difficult, but essential. As the classification of these lesions has been the subject of much controversy in the past, we reviewed the literature and summarized the distinct recognizable entities. We high-lighted recent advances in understanding clinical and histological findings in these lesions with adjunct immunohistochemistry and cytogenetics.