Case Presentation:

39 YO WM presented to PCP with lower back pain that he initially attributed to pulling muscles after playing golf. Pain persisted and got worse. His PCP ordered lumbar spine CT when he started to have cauda equina compression symptoms which showed intradural sacral mass. Initial labs revealed 45% eosinophilia and mild leukocytosis. Patient referred to neurosurgery who operated on the lesion suspected to be spinal meningioma with S1-3 laminectomy; however, pathology revealed fibroconnective tissue with acute inflammatory cells and cocci. Patient tolerated the surgery well and started on IV abx with improvement of his symptoms. Two weeks later, patient returned with bilateral legs paresthesia and night sweats. Concern about malignancy was mounting. Brain MRI ruled out metastasis. Patient symptoms worsened with upper extremities involvement and urinary hesitancy.     T7-10 hemilaminectomy was done with epidural biopsy collected.

Initial lumbar and sacral MRI showed the intradural sacral mass with repeated MRI revealing severe lumbar spine central stenosis and cord compression in addition to post-surgical fluid collection. Cervical spine MRI showed extensive enhanced circumferential epidural mass.Repeated pathology showed crushed fragments of soft tissues with numerous eosinophils. Bone marrow biopsy revealed fibrosis and numerous eosinophils. Later more sophisticated histology and gene testing showed Chronic Eosinophilic Leukemia with FIP1L1-PDGFRA rearrangement.


Patient was diagnosed with Chronic Eosinophilic Leukemia and was seen by academic oncologic team since it is very rare and was started on Imatinib with steroid. He started to have improvement of his neurologic symptoms and continued to participate with physical therapy. Initial pathology reports revealed inflammatory tissue with mistaken identity of cocci later felt to be eosinophilic granules.


Chronic eosinophilic Leukemia is one of the hyper eosinophilic syndromes (HES) which are a group of disorders marked by the sustained overproduction of eosinophils, in which eosinophilic infiltration and mediator release cause damage to multiple organs. PDGFRA-associated chronic eosinophilic leukemia is a rare condition and is caused by mutations in the PDGFRA gene.