DUSP22 rearrangement is associated with distinctive immunophenotype but not outcome in patients with systemic ALK-negative anaplastic large cell lymphoma.

DUSP22 rearrangement (R) has been associated with a favorable outcome in systemic ALK-negative anaplastic large cell lymphoma (ALCL). However, a recent study reported that patients with DUSP22-R ALK-negative ALCL have a poorer prognosis than was reported initially. In the present study, we compare the clinicopathologic features and outcomes of patients with ALK-negative ALCL with DUSP22-R (n = 22) versus those without DUSP22-R (DUSP22-NR; n = 59). Patients with DUSP22-R ALCL were younger than the patients with DUSP22-NR neoplasms (p = 0.049). DUSP22-R ALK-negative ALCL cases were more often positive for CD15, CD8, and had less frequent expression of pSTAT3 Tyr705, PD-L1, granzyme B and EMA (all p < 0.05). TP63 rearrangement (TP63-R) was detected in 3 of 66 (5%) ALKnegative ALCL cases tested and none of these cases carried DUSP22-R. Overall survival (OS) of patients with DUSP22-R ALCL was similar to that of the patients with DUSP22-NR neoplasms regardless of International Prognostic Index (IPI) score, stage, age, or stem cell transplantation status (all p > 0.05), but was significantly shorter than that of the patients with ALK+ ALCL (median OS 53 months vs undefined, p = 0.005). Five-year OS rates were 40% for patients with DUSP22-R ALCL versus 82% for patients with ALK+ ALCL. We conclude that DUSP22-R neoplasms represent a distinctive subset of ALK-negative ALCL. However, in this cohort DUSP22-R was not associated with a better clinical outcome. Therefore, we suggest that current treatment guidelines for this subset of ALK-negative ALCL patients should not be modified at this time.