Primary tonsilar ALK negative anaplastic large cell lymphoma – report of a rare entity with brief review of literature

Abstract

Primary extra-nodal non-Hodgkin's lymphomas of the head and neck account for 10%-20% of all non-Hodgkin's lymphomas, with primary tonsillar lymphoma accounting for less than 1% of cases. The recent edition of WHO has included anaplastic large cell lymphoma (ALCL) ALK negative as a provisional entity. Studies and reports are still insufficient till date, to conclusively comment about the clinical behavior and prognosis of this rare entity. Also, the expression of ALK protein, which was documented to be a favorable prognostic indicator, has now been questioned as studies documenting no favorable outcome with ALK protein expression have been reported. We present a case of primary ALCL, ALK negative, of the tonsils, presenting as unilateral tonsillar enlargement, which is not only rare but also has a distinct clinical and immunohistochemical profile.