BACKGROUND
Differentiation syndrome (DS) is a clinical syndrome first described in patients with AML undergoing treatment. It a potentially fatal complication caused by cytokine storm by maturing myeloid cells, leading to severe hypotension, respiratory failure, renal failure, pericardial effusion, fever.1 Pseudotumor cerebri is a rare complication of DS that have been mentioned with ATRA and arsenic trioxide but not with enasidenib, but requires strong consideration while undergoing evaluation.2
CASE DISCUSSION
58F w/ PMHx of recurrent AML with IDH2 mutation, FLT3 negative (s/p HiDAC and ONUREG) now on enasidenib and hypothyroidism presented with 3-day history of progressive, severe headaches with associated photosensitivity and fevers. Symptoms were refractory to high dose NSAIDs and acetaminophen at home. Vitals on presentation T 103F, HR 130s, RR 20, and down-trended to 80s/50s, unresponsive 4L IVF boluses, prompting MICU step-up for pressors, vancomyin, cefepime, and acyclovir. CTH with ethmoid air cell disease. CXR with bilateral interstitial opacities. Labs notable for hgb 10.5 (at baseline), MCV 102H, AST 56H, ALT 64H, alkaline phosphatase 144, Tbili 1.5H, and normal lactate. Additional, serum and lumbar bacterial, viral, and fungal studies were all negative. TTE negative for vegetation, which prompted infectious regimen discontinuation, and initiation of decadron while holding home enasidenib. She showed remarkable symptomatic improvement and all labs normalized including elevated transaminases. She was discharged with decadron taper and resumption of enasidenib, with reduction in dosage after two subsequent hospitalizations for similar presentation.
CONCLUSION
DS diagnosis can be challenging because its presentation can mimic those of leukemic progression or other acutely fatal comorbidities. Additionally, DS due to enasidenib can occur 7 days to 5 months after its initiation, unlike in ATRA and arsenic trioxide where DS typically occurs 7 to 12 days after initiation.3 Therefore, it is vital to perform prompt, thorough evaluation to avoid any delays in corticosteroid therapy.