Central nervous system blastic crisis in chronic myeloid leukemia on imatinib mesylate therapy: a case report

Leukostasis With Isolated Central Nervous System Involvement in Chronic Phase of Chronic Myelogenous Leukemia

Chronic myelogenous leukemia (CML) is a hematologic malignancy with unique significance to the field of hematology and oncology, specifically due to the development of tyrosine kinase inhibitors (TKIs). CML often presents with nonspecific symptoms, and the quality of life in patients with CML has drastically improved as a result of TKIs. However, complications of CML including the risk of transforming into life-threatening blast crises continue to exist. Further, as most patients are asymptomatic in the chronic phase, patients often present with serious complications associated with noncompliance to TKIs. For example, central nervous system (CNS) manifestations of CML have been reported, both as the initial presentation of undiagnosed CML and as known complication of uncontrolled CML. Hyperleukocytosis is a manifestation of uncontrolled CML and leukostasis is a complication, occurring in cases of acute myeloid leukemia (AML). Here we present a rare case of leukostasis in a patient with known CML presenting on computed tomography (CT) as intracranial masses in the chronic phase. Our goal is to discuss this rare case of leukostasis in adult CML and describe its management.

Treatment of blast phase chronic myeloid leukaemia: A rare and challenging entity

Despite the success of BCR-ABL-specific tyrosine kinase inhibitors (TKIs) such as imatinib in chronic phase (CP) chronic myeloid leukaemia (CML), patients with blast phase (BP)-CML continue to have a dismal outcome with median survival of less than one year from diagnosis. Thus BP-CML remains a critical unmet clinical need in the management of CML. Our understanding of the biology of BP-CML continues to grow; genomic instability leads to acquisition of mutations which drive leukaemic progenitor cells to develop self-renewal properties, resulting in differentiation block and a poor-prognosis acute leukaemia which may be myeloid, lymphoid or bi-phenotypic. Similar advances in therapy are urgently needed to improve patient outcomes; however, this is challenging given the rarity and heterogeneity of BP-CML, leading to difficulty in designing and recruiting to prospective clinical trials. This review will explore the treatment of BP-CML, evaluating the data for TKI therapy alone, combinations with intensive chemotherapy, the role of allogeneic haemopoietic stem cell transplantation, the use of novel agents and clinical trials, as well as discussing the most appropriate methods for diagnosing BP and assessing response to therapy, and factors predicting outcome.

Isolated Ocular Manifestations in Chronic Myeloid Leukaemia

BACKGROUND

Chronic myeloid leukaemia (CML) presenting with only ocular manifestations either at the initial stage of diagnosis or at relapse is uncommon. We report two cases of CML presenting with isolated visual symptoms.

CASE SERIES

The first case is a 21-year-old healthy gentleman who presented with left eye painless loss of vision for a one-week duration. Visual acuity was 6/60 in the left eye and 6/6 in the right eye. There were scattered retinal haemorrhages in both eyes and a sub-macular bleed over the left eye. The full blood count revealed a high white cell count of 134.6 × 10⁹/L. Peripheral blood smear showed hyper-leucocytosis with absolute eosinophilia and basophilia and the presence of blasts suggestive of CML thus chemotherapy was commenced. The second case is a 28-year-old in haematological, molecular, and cytogenic remission from CML for the past two years, presented with left eye painless vision loss for five days duration. Vision in the left eye was counting fingers. There was a large subretinal mass involving the left optic disc. Magnetic resonance imaging of the brain and orbit showed an elliptical orbital mass at the left globe posteriorly with diffuse thickening of the optic nerve. The patient was diagnosed as CML relapsed to the left optic nerve. He underwent intrathecal chemotherapy and orbital irradiation.

CONCLUSION

Both these cases are unique since the manifestation of CML was with only ocular features at the time of presentation as per in the first case during the initial diagnosis and in the second case during relapse. This highlights that it is evident that the knowledge of ocular involvement in leukaemia is crucial since the eye is the only organ where leukemic infiltration to nerves and blood vessels can be observed directly. Recognizing fundus changes in leukaemia allows earlier diagnosis and prompt treatment. These case reports highlight the importance of recognizing early fundus changes, which should allow earlier diagnosis and treatment.

Leukaemia: a model metastatic disease

In contrast to solid cancers, which often require genetic modifications and complex cellular reprogramming for effective metastatic dissemination, leukaemic cells uniquely possess the innate ability for migration and invasion. Dedifferentiated, malignant leukocytes retain the benign leukocytes' capacity for cell motility and survival in the circulation, while acquiring the potential for rapid and uncontrolled cell division. For these reasons, leukaemias, although not traditionally considered as metastatic diseases, are in fact models of highly efficient metastatic spread. Accordingly, they are often aggressive and challenging diseases to treat. In this Perspective, we discuss the key molecular processes that facilitate metastasis in a variety of leukaemic subtypes, the clinical significance of leukaemic invasion into specific tissues and the current pipeline of treatments targeting leukaemia metastasis.

Is it always cancer? A curious case of benign intracranial hypertension in chronic myeloid leukemia

28-year-old African American female with chronic myeloid leukemia (CML) presented with blurry vision for 4-5 days prior to presentation associated with right-sided headaches. Patient was on treatment for the CML but never had hematological remission. Patient saw an ophthalmologist who told her that she has bilateral optic disc swelling and advised her to get an MRI of the brain. She came to the ER due to worsening headache and blurry vision. The funduscopic examination showed significant bilateral papilledema. Laboratory evaluation revealed a leukocytosis of 240 × 103/uL with platelet count of 1,202 × 103. The white cell differential count showed 17% blasts along with myelocytes and meta-myelocytes. MRI of brain revealed non-specific CSF flair signal. Lumbar puncture (LP) showed significantly elevated opening pressures. The CSF composition was however normal. The patient felt much relief of her symptoms following the LP. The papilledema was thought to be due to benign intracranial hypertension (ICH), which was attributed to poor CSF absorption due to resistance to flow of CSF caused by the high WBC count. She received 2 cycles of leukopheresis which dropped her WBC count. She was also started on acetazolamide for the benign ICH and her symptoms improved considerably. Patients with CML can thus present with symptoms mimicking CNS involvement of the disease such as headaches and blurry vision, but that could be attributed to the poor CSF resorption given the leukocytosis rather than spread of the disease itself.

Central nervous system blast crisis of chronic myeloid leukaemia misdiagnosed as tubercular meningitis

Chronic Myeloid Leukaemia (CML) presenting with isolated Central Nervous System (CNS) blast crisis is an uncommon entity. A 22-year-old man, diagnosed with chronic phase CML in 2011 and was in haematological and cytogenetic remission until July 2016, had acute onset headache and vomiting with meningeal signs and was admitted elsewhere, investigated by brain imaging and cerebrospinal fluid (CSF) analysis and suspected to have tubercular meningitis, for which steroids and antitubercular medications were started. The patient's sensorium further deteriorated, and Ventriculoperitoneal shunt surgery was done for hydrocephalus by a neurosurgeon. After 2 months of the illness, he was admitted to our hospital with a persistent headache, vomiting and altered sensorium. CSF for cytospin confirmed myeloid blasts. He was still in haematological remission. So, a diagnosis of isolated CNS blast crisis was made. The patient was started on triple intrathecal chemotherapy and cranial radiotherapy. He had improvement with treatment and is still in remission.

Neurological Complications of the Leukemias Across the Ages

PURPOSE OF REVIEW

Acute and chronic leukemias are heterogeneous diseases and can affect any part of the body upon initial discovery. Understanding the sequela of systemic involvement is key for proper diagnosis and treatment.

RECENT FINDINGS

Over the decades, new research has emerged regarding neurological complications of the myeloid or lymphoid leukemias. Central nervous system involvement usually confers a poor prognosis and requires emergent treatment. Standard of care still involves systemic therapy, intrathecal administration of chemotherapeutic agents, and cranial radiation. Treatment-related side effects can occur and need to be recognized by any practitioner involved with patient care. It is imperative to understand neurologic complications from leukemia to prevent delays and initiate necessary treatment to maintain neurologic and cognitive function.

Isolated CNS Blast Crises in Chronic Myeloid Leukaemia Presenting as Hypertrophic Pachymeningitis and Bilateral Optic Neuritis: A Case Report

Extramedullary blast crises of Chronic Myeloid Leukaemia (CML) involving CNS is rare and usually accompanies systemic relapse. Isolated CNS blast relapse is an extremely uncommon event. A 35-year-old male was diagnosed with chronic phase (CP) CML two years back at our hospital and was started on imatinib 400 mg daily. Patient achieved haematological and cytogenetic remission at three and 12 months respectively but was non-compliant with medications thereafter. He presented to our emergency with headache and bilateral visual loss. CNS examination revealed neck rigidity and fundoscopy revealed disc edema with retinal vein dilatation and haemorrhages. Cerebrospinal fluid (CSF) analysis revealed lymphocytic pleocytosis and a positive cytospin for myeloid blasts. MRI brain suggested pachymeningeal enhancement involving falx cerebri and tentorium along with bilateral optic nerve thickening. Patient maintained cytogenetic remission at current presentation. A diagnosis of isolated CNS blast crises with pachymeningitis and bilateral optic nerve involvement was made and two doses of intrathecal chemotherapy were administered. However, patient died due to a rapidly downhill course. A previously unreported finding of pachymeningitis with bilateral optic neuritis has been highlighted in this case, along with a brief review of this rare condition.

Isolated central nervous system relapse in chronic myeloid leukemia

Chronic myeloid leukemia is a myeloproliferative disorder that has three distinguished phases: chronic, accelerated, and blastic. In extremely rare cases, the blast phase can affect the central nervous system without concomitant bone marrow involvement. We report the case of a patient with chronic myeloid leukemia who, despite having achieved complete cytogenetic remission in the bone marrow for several years, experienced a blast crisis of the central nervous system following an episode of infectious meningoencephalitis.

Dasatinib maintenance therapy after allogeneic hematopoietic stem cell transplantation for an isolated central nervous system blast crisis in chronic myelogenous leukemia

A 22-year-old male with Ph-positive chronic myelogenous leukemia (CML) was started on treatment with imatinib. After 12 months of therapy, he achieved a complete cytogenetic response (CCyR). Although the CCyR persisted in his bone marrow, he developed an isolated CML blast crisis in his central nervous system (CNS) after 29 months of therapy. He underwent allogeneic hematopoietic stem cell transplantation (HSCT) following combination therapy with dasatinib, intrathecal chemotherapy and cranial irradiation. Subsequently, 168 days after allogeneic HSCT, he was started on dasatinib maintenance therapy to prevent a CNS relapse. Thirty-eight months after allogeneic HSCT, he has sustained a complete molecular response in both bone marrow and CNS. We believe dasatinib has the potential to prevent CNS relapse if used for maintenance therapy after allogeneic HSCT.

Isolated central nervous system relapse of chronic myeloid leukemia after allogeneic hematopoietic stem cell transplantation

BACKGROUND

This case report highlights the relevance of quantifying the BCR-ABL gene in cerebrospinal fluid of patients with suspected relapse of chronic myeloid leukemia in the central nervous system.

CASE PRESENTATION

We report on a female patient with isolated central nervous system relapse of chronic myeloid leukemia (CML) during peripheral remission after allogeneic hematopoietic stem cell transplantation. The patient showed a progressive cognitive decline as the main symptom. MRI revealed a hydrocephalus and an increase in cell count in the cerebrospinal fluid (CSF) with around 50% immature blasts in the differential count. A highly elevated BCR-ABL/ ABL ratio was detected in the CSF, whilst the ratio for peripheral blood and bone marrow was not altered. On treatment of the malresorptive hydrocephalus with shunt surgery, the patient showed an initial cognitive improvement, followed by a secondary deterioration. At this time, the cranial MRI showed leukemic infiltration of lateral ventricles walls. Hence, intrathecal administration of cytarabine, methotrexate, and dexamethasone was initiated, which caused a significant decrease of cells in the CSF. Soon after, the patient demonstrated significant cognitive improvement with a good participation in daily activities. At a later time point, after the patient had lost the major molecular response of CML, therapy with dasatinib was initiated. In a further follow-up, the patient was neurologically and hematologically stable.

CONCLUSIONS

In patients with treated CML, the rare case of an isolated CNS blast crisis has to be taken into account if neurological symptoms evolve. The analysis of BCR-ABL in the CSF is a further option for the reliable detection of primary isolated relapse of CML in these patients.

Three paths to better tyrosine kinase inhibition behind the blood-brain barrier in treating chronic myelogenous leukemia and glioblastoma with imatinib

Chronic myelogenous leukemia (CML) can be controlled for years with the tyrosine kinase inhibitor imatinib but because imatinib poorly penetrates the blood-brain barrier (BBB), on occasion, the CML clone will thrive and evolve to an accelerated phase in the resulting imatinib sanctuary within the central nervous system. In this, CML resembles glioblastoma in that imatinib, which otherwise may be effective, cannot get to the tumor. Although a common street drug of abuse, methamphetamine is Food and Drug Administration-approved and marketed as a pharmaceutical drug to treat attention-deficit disorders. It has shown the ability to open the BBB in rodents. We have some clinical hints that it may do so in humans as well. This short note presents three new points potentially leading to better tyrosine kinase inhibition behind the BBB: 1) Pharmaceutical methamphetamine may have a useful role in treating both CML and glioblastoma by allowing higher imatinib concentrations behind the BBB. 2) The old antidepressant and monoamine oxidase inhibitor selegiline, used to treat Parkinson disease, is catabolized to methamphetamine. Selegiline, as a nonscheduled drug,may therefore be an easier way to open the BBB, allowing more effective chemotherapy with tyrosine kinases. 3) Dasatinib is a tyrosine kinase inhibitor with a spectrum of inhibition only partially overlapping that of imatinib and a mechanism of tyrosine kinase inhibition that is different from that of imatinib. The two should be additive. In addition, dasatinib crosses the BBB poorly, and it can therefore be expected to benefit from methamphetamine-assisted entry.

Metronidazole leads to enhanced uptake of imatinib in brain, liver and kidney without affecting its plasma pharmacokinetics in mice

Objectives

The pharmacokinetic interaction between metronidazole, an antibiotic–antiparasitic drug used to treat anaerobic bacterial and protozoal infections, and imatinib, a CYP3A4, P-glycoprotein substrate kinase inhibitor anticancer drug, was evaluated.

Methods

Male imprinting control region mice were given 50 mg/kg imatinib PO (control group) or 50 mg/kg imatinib PO, 15 min after 40 mg/kg PO metronidazole (study group). Imatinib plasma, brain, kidney and liver concentrations were measured by HPLC and non-compartmental pharmacokinetic parameters estimated.

Key findings

Metronidazole coadministration resulted in a double-peak imatinib disposition profile. The maximum concentration (Cmax) decreased by 38%, the area under the curve (AUC0–∞) decreased by 14% and the time to Cmax (Tmax) was earlier (50%) in plasma. Apparent volume of distribution (VSS/F) and oral clearance (Cl/F) increased by 21% and 17%, respectively. Imatinib tissue penetration was higher after metronidazole coadministration, with 1.7 and 2.1-fold AUC0–∞ increases in liver and kidney, respectively. Metronidazole increased imatinib's tissue-to-plasma AUC0–∞ ratio in liver from 2.29 to 4.53 and in kidney from 3.04 to 7.57, suggesting higher uptake efficiency. Brain Cmax was 3.9-fold higher than control and AUC0–t last was 2.3-fold greater than plasma (3.5% in control group). No tissue-plasma concentration correlation was found.

Conclusions

Metronidazole slightly decreased imatinib systemic exposure but enhanced liver, kidney and brain penetration, probably due to metronidazole-mediated inhibition of P-glycoprotein and other efflux transporters. The high brain exposure opens possibilities for treatment of glioma and glioblastoma. Renal and hepatic functions may need to be monitored due to potential renal and hepatic toxicity.

Central nervous system blast crisis in chronic myeloid leukemia on imatinib mesylate therapy: report of two cases

Chronic myeloid leukaemia is a chronic myeloproliferative disorder characterised by a reciprocal translocation between chromosomes 9 and 22 and thereby formation of the Philadelphia chromosome. Imatinib mesylate (STI-571) is a potent and selective inhibitor of BCR-ABL tyrosine kinase and has emerged as a treatment of choice in chronic myeloid leukaemia (CML) patients in chronic phase. It has shown activity in CML patients in the chronic phase or blastic phase. However there is poor penetration of the central nervous system (CNS) by the drug or its active metabolites. Therefore the CNS acts as a sanctuary site for malignant cells for CML patients treated with Imatinib. We report cases of two CML patients on Imatinib therapy, who were in haematological remission but developed CNS disease.

Clinical responses observed with imatinib or sorafenib in melanoma patients expressing mutations in KIT

Background:

Mutations in KIT are more frequent in specific melanoma subtypes, and response to KIT inhibition is likely to depend on the identified mutation.

Methods:

A total of 32 patients with metastatic acral or mucosal melanoma were screened for mutations in KIT exons 11, 13 and 17.

Results:

KIT mutations were found in 38% of mucosal and in 6% of acral melanomas. Three patients were treated with imatinib and one with sorafenib. All four patients responded to treatment, but three have since progressed within the brain.

Conclusion:

The observed clinical responses support further investigation of KIT inhibitors in metastatic melanoma, selected according to KIT mutation status.

Characterisation of extramedullary relapse in patients with chronic myeloid leukemia in advanced disease after allogeneic stem cell transplantation

Recently, higher extramedullary relapse rates following allogeneic stem cell transplantation (SCT) in myeloid malignancies were reported e.g. because of selection of poor-risk patients. We analysed five consecutive patients with post-transplant extramedullary relapse of chronic myeloid leukemia (CML) out of a total of 24 patients (21%) undergoing allo-SCT. All five patients with extramedullary relapse had clonal evolution and a history of blast phase (BP). In particular, 56% of the patients in BP had extramedullary relapse with no extramedullary relapse in patients with chronic/accelerated phase. Most frequent manifestation sites were the skeletal system, the muscles/subcutaneous tissue and the central nervous system. In one case chloroma was mimicking myositis of the lower limbs. Combined approaches were performed including irradiation (n = 4), chemotherapy (n = 2), IM (n = 2), dasatinib (n = 4), nilotinib (n = 1), a novel aurora-kinase-inhibitor (n = 1), donor lymphocytes (n = 2) or a second allo-SCT (n = 2). Transient response was achieved in one case, stable partial remissions in two cases, whereas two cases were refractory. Research should focus on prospective studies aiming to improve treatment of extramedullary relapse in stem cell recipients with CML with a special focus on the role of second generation tyrosine kinase inhibitors.

Is p190 bcr-abl rearrangement necessary for acute transformation in some p210 CML of childhood?

Chronic myeloid leukemia (CML) is a rare disease in childhood which is almost exclusively associated with bcr-abl p210 (M-bcr) rearrangements. It has been suggested that co-expression of p190 and p210 may be a pathway of CML progression in adult patients. We report two cases of pediatric patients with a diagnosis of CML who presented co-expression of the p210 and p190 transcripts during progression to the blastic phase. The present data suggest that p190 may be a secondary event in at least some cases of childhood CML, suggesting an association with progression to a blastic crisis in these patients.