We report here on a rare case of a patient who presented with an extramedullary B lymphoblastic crisis as an initial manifestation of chronic myelogenous leukemia (CML). A 71-year-old man visited the emergency room due to suddenly developed dysarthria and right side weakness. Emergency craniotomy was done under the presumptive diagnosis of subdural hemorrhage. During the operation, a poorly demarcated firm mass was identified in the leptomeningeal space. Microscopically, the majority of the tumor was composed of monotonous immature cells with blast morphology, and these cells were immunoreactive for TdT, CD34, CD10 and CD20, indicating the precursor B-cell phenotype. The peripheral area of the tumor consisted of myeloid cells in various stages of maturation, and these cells were reactive for myeloperoxidase, chloroacetate esterase, CD43 and CD15.
FISH analysis using the LSI bcr-abl dual color probe showed gene fusion signals in both the B-lymphoblasts and myeloid cells. The peripheral blood and bone marrow findings were consistent with CML with no evidence of a blast crisis.
Cytogenetic study of the bone marrow demonstrated the 46, XY, t(9;22)(q34;q11) chromosome. A diagnosis of extramedullary B lymphoblastic blast crisis in a patient with Philadelphia chromosome-positive CML was made. Despite treatment, the patient died 3 months after he was diagnosed.
Although chronic myelogenous leukemia (CML) may be involved in any part of the body, infiltration of the body fluid has rarely reported in the literature. Here we report on a 35 year-old male patient who was diagnosed chronic myelogenous leukemia ten years previously and he received allogenic hematopoietic stem cell transplantation. He then presented with left knee pain eight years after the initial diagnosis.
MRI revealed a soft tissue mass at the distal femur.
Cytology of the joint fluid revealed myeloblasts, promyelocytes, eosinophilic myelocytes, band neutrophils, megakaryocytes and orthochromatic erythroblasts, which was all consistent with leukemic infiltration of the knee joint fluid. The immunohistochemistry was positive for CD34, CD117 and myeloperoxidase (MPO). Despite that the patient underwent radiation therapy, MRI revealed growth of the mass, and ten months later, the lymphoid blast phase of CML was confirmed after biopsy. The patient received an above knee amputation. Five months later, multiple masses were revealed on PET-CT at the left iliopsoas muscle, abdominal wall and bones. Bilateral pleural effusion occurred shortly after this. Cytologic evaluation of the pleural fluid also revealed blast-like cells, and histologic evaluation of the abdominal mass confirmed the lymphoid blast phase of CML with positivity for CD3, UCHL-1, CD34 and CD117, but negativity for MPO.