Plasmablastic lymphoma of transverse colon: a rare case report

Plasmablastic lymphoma (PBL) is a rare aggressive subtype of non-Hodgkin's lymphoma with large neoplastic cells. It is usually associated with human immunodeficiency virus (HIV) infection but also identified in patients with solid organ transplantation and in immunocompetent patients. It frequently presents as a mass in oral cavity, but has also been described in other extra-oral sites like gastrointestinal track, skin, genitourinary track, nasal cavity, paranasal sinuses, etc. It is characterized by plasmablastic features and an immunoprofile close to plasma cells, Epstein–Barr virus (EBV) positivity and MYC gene dysregulation. We report a case of a 40 year old HIV positive male who presented with intestinal obstruction having mass in transverse colon. Histopathological examination of the excised mass revealed submucosa and muscularis propria infiltrated by monotonous population of medium to large sized lymphoid cells with plasmacytic differentiation. The tumour cells were immunoreactive for EMA, CD138 and Vimentin and immunonegative for LCA, CK, S-100, Chromogranin, CD20, CD30, CD3. Thus the final diagnosis of Non-Hodgkins Lymphoma – Consistent with Plasmablastic Lymphoma was made. PBL should be carefully differentiated from Plasmablastic Plasma cell myeloma, other CD20 negative B-cell neoplasma i.e. primary effusion lymphoma, anaplastic lymphoma Kinase (ALK)-positive large B-cell lymphoma, large B-cell lymphoma arising in human herpesvirus 8 (HHV-8)-associated multicentric Castleman disease.