Cytokeratin and CD56 aberrant co-expression in diffuse large B-cell lymphoma, NOS misinterpreted as metastatic neuroendocrine carcinoma by FNAC

Aberrant expression of epithelial and neuroendocrine markers is rare in diffuse large B-cell lymphoma (DLBCL) and can lead to erroneous diagnosis with inappropriate treatment. This case report describes a case of DLBCL with a co-expression of cytokeratins and CD56 that was misdiagnosed as metastatic neuroendocrine carcinoma.