KITLG and anaplastic large cell lymphoma: In anaplastic large-cell lymphoma, the cohesive growth pattern, lack of leucocyte common antigen (CD45RB) in up to 38%,105 frequent EMA expression, null phenotype (10–20% of cases), rare keratin expression (particularly broad-spectrum antikeratin antibody KL1)106 make carcinoma a strong consideration, as illustrated by a Workshop case of a CD30+ large pelvic mass in a 37-year-old female with all these features.