Conclusion: Pathologists and otorhinolaryngologists should be aware that in situ MCL may be observed in nasopharynx. It may be appropriate to perform cyclinD1 immunostain, even in cases with clinical and histological findings compatible with lymphoid hyperpasia. The patients should be examined thoroughly, since in situ MCL may accompanied by an overt lymphoma in other sites or it may be a precursor of an overt MCL.