What are hallmarks of ALK+ anaplastic lymphoma?

• Characteristic “hallmark” cells that show eccentrically-placed, large, horse-shoe shaped nuclei with multiple nucleoli with abundant amphophilic cytoplasm. • CD30, ALK • CD2, and CD4 are most commonly expressed (40-70%) • CD3 is negative in more than 75% of the cases • CD45 can be negative