Title: ALK Positive diffuse large B-cell lymphoma: An archival study from a regional cancer centre in South India
Authors: Suma Mysore Narayana, Channagiri Premalatha, Suresh babu Mallekavu, Usha Amirtham, Shankaranand Bharathnur, Rekha V Kumar
DOI: https://dx.doi.org/10.18535/jmscr/v5i1.118
Abstract
Background: Anaplastic lymphoma kinase-positive diffuse large B-cell lymphoma (ALK-positive DLBCL) is a rare subtype of DLBCL.
Patients and Methods: We report detailed clinical and pathologic features of five cases of Anaplastic lymphoma kinase-positive diffuse large B-cell lymphoma (ALK-DLBCL), from our archives between January 2011 and June 2016, a rare entity with only 77 reported cases in the literature. This study is the third largest of all reported series.
Results: In our series we noticed male predominance with male to female ratio of 3.5:1 Three of them presented with nodal disease and two with extranodal. All patients were immunocompetent and were seronegative for HIV.All cases exhibited plasmablastic morphology. By immunohistochemistry, all 5 cases lacked expression of pan-B-cell antigens CD20.CD79a and Pax5 were variable. All were CD30 negative. They consistently expressed cytoplasmic ALK-1, CD138, cytoplasmic light chain, CD45, EMA, CD4. Unlike in any other series one of our case showed association of EBV (EBER by RISH).According to the follow-up information available one expired after 15months (Case 1) and rest have either progressive disease or stable.
Discussion and Conclusion: ALK+DLBCL is an entity with immunoblastic or plasmablastic microscopical appearance with round nuclei, prominent single central nucleoli and moderate amounts of eosinophilic cytoplasm. It is likely that the incidence of this type of lymphoma is underestimated. The recognition of ALK-positive DLBCL as a distinct entity is important because most patients follow an aggressive disease course, are unlikely to respond favourably to the current standard of care (R-CHOP) for CD20-positive DLBCL. Further prospective studies are needed to optimize therapies for this entity.
Keywords: Anaplastic lymphoma kinase, ALK, diffuse large B cell lymphoma, DLBCL
Suma Mysore Narayana, MBBS MD DNB
Assistant Professor of Pathology, Department of Histopathology,
Kidwai Memorial Institute of oncology,
Bangalore-560029
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