ALK Positive DLBCL - A Report of two cases and review of literature

Anaplastic Lymphoma Kinase (ALK) positive Diffuse large B cell lymphoma (ALKDLBCL) is clinicopathologically unique, characterised by plasmablastic appearance, CD20 negativity and ALK positivity. It is a recently recognised subtype of lymphoma and has been included in the recent classification of lymphomas by WHO. Till date, close to 50 cases have been reported in literature. The disease has an aggressive course, and is often resistant to standard CHOP chemotherapy. We present two cases where Lymph node biopsy was suggestive of ALK - DLBCL. The first case is a 59 year old male with cervical adenopathy and cutaneous lesions. Though extranodal presentations are well known in this subtype of Non hodgkins Lymphoma, skin involvement has not been reported previously. The second case is a nodal presentation where the response to treatment was unsatisfactory and the patient had a disease relapse within a short duration. This highlights the relatively poor prognosis of this rare variant of DLBCL, in concordance with the existing literature. A review of the existing literature pertaining to the ALK-DLBCL is presented here and possible suggestions to improve the clinical outcome in this poor prognostic subset of Non Hodgkin Lymphoma is put forward.