Anaplastic Lymphoma Kinase positive large B cell lymphoma of ileocaecal mesentery: A case report.

ALK+ large B cell lymphoma (LBCL) is a very rare aggressive neoplasm. It accounts for less than 1% of diffuse large B cell lymphoma (DLBCL). This is a case report of ALK+ DLBCL in a 34-year-old woman with an ileocaecal mesenteric mass. Microscopically, the neoplastic cells were of high grade along with a spindle cell component. Immunohistochemistry revealed ALK+, MUM-1+, LCA+, Vimentin+, EMA+ and negative for CK 20, CK 7, neuroendocrine, melanocytic, muscle specific, and GIST panel markers. This case report, hence, presents the rarity of this tumor.