Meningeal chloroma (granulocytic sarcoma) in acute lymphoblastic leukemia mimicking a falx meningioma

Dural-based lesions: is it a meningioma?

PURPOSE

Meningiomas are the most common extra-axial intracranial neoplasms with typical radiological findings. In approximately 2% of cases, histopathological reports reveal different neoplasms or non-neoplastic lesions that can closely mimic meningiomas. We describe radiological features of meningioma mimics highlighting imaging red flags to consider a differential diagnosis.

METHODS

A total of 348 lesions with radiological diagnosis of meningiomas which underwent to surgical treatment or biopsy between December of 2000 and September of 2014 were analyzed. We determined imaging features that are not a typical finding of meningiomas, suggesting other lesions. The following imaging characteristics were evaluated on CT and MRI: (a) bone erosion; (b) hyperintensity on T2WI; (c) hypointensity on T2WI; (d) bone destruction; (e) dural tail; (f) leptomeningeal involvement; (g) pattern of contrast enhancement; (h) dural displacement sign.

RESULTS

We have a relatively high prevalence of meningioma mimics (7.2%). Dural-based lesions with homogeneous contrast enhancement (52%) are easily misdiagnosed as meningiomas. Most lesions mimic convexity (37.5%) or parafalcine (21.9%) meningiomas. We have determined five imaging red flags that can alert radiologists to consider meningioma mimics: (1) bone erosion (22.2%); (2) dural displacement sign (36%); (3) marked T2 hypointensity (32%); (4) marked T2 hyperintensity (12%); (5) absence of dural tail (48%). The most common mimic lesion in our series was hemangiopericytomas, followed by lymphomas and schwannomas.

CONCLUSION

The prevalence of meningioma mimics is not negligible. It is important to have awareness on main radiological findings suggestive of differential diagnosis due to a wide range of differentials which lead to different prognosis and treatment strategies.

Treatment Outcomes of Intracranial Myeloid Sarcomas: A Meta-Analysis

OBJECTIVE

Intracranial myeloid sarcomas (IMS) are rare central nervous system manifestations of malignant hematopoietic neoplasms of myeloid origin such as acute myeloid leukemia and chronic myeloid leukemia. Reported cases in the literature are limited to primarily case reports. We present a systematic review of this rare central nervous system tumor, characterizing the clinical presentation, tumor location, histopathology, and available treatment modalities. We correlate these variables with mortality, recurrence, and complications to suggest optimal management strategies for IMS.

METHODS

A systematic literature search was performed across Ovid MEDLINE, Scopus, and Embase using 14 search terms in accordance to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. This systematic review examines variables such as patient age, tumor location, size, presenting symptoms, treatment modality, extent of resection, and mortality. We performed descriptive analyses to identify bivariate associations between patient characteristics, treatment, and outcomes.

RESULTS

The mean age at diagnosis was 34.8 years, and the most common etiology was acute myeloid leukemia (68.8%). The most common presenting symptoms were headache (45.5%), vision complaints (27.3%), and weakness/motor symptoms (21.2%). IMS were most commonly located in the temporal lobe (10.1%), cerebellum (10.1%), or falcine/parasagittal (10.1%) region. Patients who received radiotherapy (P < 0.001) or chemotherapy (P < 0.001) had lower rates of mortality versus those who did not. Surgical treatment and extent of resection were not significantly associated with mortality (P > 0.05).

CONCLUSION

The use of adjuvant radiotherapy or chemotherapy for IMS significantly reduces mortality, confirming IMS as a cranial manifestation of a systemic disease. Although surgical treatment is indicated for histopathologic diagnosis and to relieve mass effect, the extent of resection does not predict overall survival.

Isolated Central Nervous System Chloroma as a Presenting Sign of Relapsed Pediatric Acute Lymphoblastic Leukemia

Central nervous system (CNS) chloromas are an exceedingly rare presentation of CNS relapse in acute lymphoblastic leukemia (ALL). We report a relapsed ALL patient who presented with 2 separate chloromas and cerebrospinal fluid lymphoblastocytosis, and outline a treatment plan of systemic chemotherapy and CNS-directed radiation therapy. A review of the literature indicates that multiagent chemotherapy combined with CNS radiotherapy is effective, with hematopoietic stem cell transplantation used in half of reported cases. We conclude that intensive systemic multiagent chemotherapy with CNS-directed radiation therapy can be successfully used to treat relapsed pediatric ALL with CNS lymphoblastic chloroma.

Role of diffusion-weighted imaging for detecting bone marrow infiltration in skull in children with acute lymphoblastic leukemia

PURPOSE

We aimed to determine whether diffusion-weighted imaging (DWI) with apparent diffusion coefficient (ADC) measurement can detect skull bone marrow infiltration in newly diagnosed acute lymphoblastic leukemia (ALL) children before therapy and normalization in complete remission after treatment.

METHODS

Fifty-one newly diagnosed acute lymphoblastic leukemia (ALL) patients and 30 healthy age-matched subjects were included. Cranial magnetic resonance imaging (MRI) scans were reviewed, and skull marrow ADC values were compared before treatment and in complete remission after therapy.

RESULTS

Skull marrow infiltration, manifested with abnormal DWI signals, was present in 37 patients (72.5%) before treatment. Of these, 23 (62.2%) showed scattered signal abnormalities and 14 (37.8%) showed a uniform abnormal signal pattern. Compared with the control group, ADC was significantly decreased in patients with ALL. DWI signal intensity and ADC normalized in patients with complete remission.

CONCLUSION

DWI is a useful and noninvasive tool for detecting skull infiltration in ALL children before treatment and normalization at complete remission after therapy, and it is superior to conventional MRI in terms of conspicuity of these lesions. DWI could be used as an MRI biomarker for evaluation of treatment in ALL children.

A Man in His 40s With Headache, Lethargy, and Altered Mental Status

A man in his 40s presented with 1 month of worsening confusion, fatigue, and headache. Results from laboratory analyses were notable for a complete white blood cell count of 17 000/μL (31% blast cells), a platelet count of 76 000/μL, and a hemoglobin level of 16.6 g/dL. Imaging studies revealed a large mixed-attenuation subdural collection in the right frontal region with prominent mass effect. The patient underwent an emergency neurosurgical procedure. The differential diagnosis, pathologic findings, and diagnosis are discussed.

Granulocytic sarcoma of the spine: MRI and clinical review

OBJECTIVE

Granulocytic sarcoma is a tumor formed by myeloid precursors at an extramedullary site. The purpose of this study was to evaluate the MRI findings and clinical manifestations in 32 cases of granulocytic sarcoma of the spine.

MATERIALS AND METHODS

Thirty-two patients (21 males, 11 females; mean age, 32 years) with myeloid leukemia and spinal granulocytic sarcoma were included in this study. All of the patients underwent radiotherapy with chemotherapy, and four patients underwent surgical decompression or excisional biopsy. All 32 patients underwent MRI of the spine; 21 patients underwent follow-up MRI.

RESULTS

Nine patients had spinal granulocytic sarcoma in the initial manifestation of leukemia. The other 23 diagnoses were made during a remission or relapse period. The lumbosacral and thoracic portions of the spine were commonly involved. Twenty-seven patients had multiple or contiguous multilevel involvement. According to location, spinal granulocytic sarcoma was classified as epidural in the central spinal canal, epidural along the nerve course, thickening of the nerve root itself, or prevertebral. Lesions were seen as isointense on T1-weighted images and had intermediate signal intensity with homogeneous enhancement on T2-weighted images. Nine patients had complete reduction of the tumor volume, and 12 patients had partial reduction. The median survival period was 9 months, and the 1-year survival rate was 41%.

CONCLUSION

Knowledge of the imaging findings of spinal granulocytic sarcoma, which consists of multiple extramedullary masses with diffuse leukemic bone marrow infiltration, can lead to early diagnosis and appropriate treatment to reduce neurologic symptoms.

Diagnostic pitfalls in acute leukemia

In most children presenting with the common signs and symptoms of leukemia, the diagnosis is readily made. However, unusual features of the disease and the absence of abnormalities on the complete blood count may render the diagnosis problematic, especially if this malignancy is not suspected. The current report focuses on the unusual presentation of leukemia and the difficulties in the diagnosis of the malignancy.

Extramedullary Intradural Spinal Tumors: A Pictorial Review

Defining the location of tumors and mass lesions of the spine in relation to the spinal cord and the dura is of the utmost importance as certain types of lesions tend to occur in certain locations. The differential diagnostic considerations will vary according to location of the mass lesion as will the treatment and prognosis of these various lesions. The category of extramedullary intradural masses includes a variety of lesions from meningiomas and nerve sheath tumors (neurofibromas, schwannomas) to less common tumors (hemangiopericytoma), metastases, benign tumors (lipoma, dermoid, epidermoid), inflammatory disorders (arachnoid adhesions, sarcoidosis), vascular lesions (spinal-dural arteriovenous fistula), and cystic lesions (perineural or Tarlov cysts). Characteristic magnetic resonance imaging findings are helpful for localization and characterization of these lesions before treatment, as well as for follow-up after treatment. We present a pictorial review of the various extramedullary intradural lesions of the spine, with pathologic correlation. We discuss imaging features that are typical for the various entities and describe various therapeutic options that are important considerations for surgical treatment of these lesions.

Intracranial myeloid sarcoma: conventional and advanced MRI findings

Chloroma (myeloid or granulocytic sarcoma) is a rare type of tumour comprising immature granulocytic cells. It generally accompanies acute myeloid leukaemia and, rarely, other myeloproliferative disorders. When presenting as dural-based mass lesions, radiological differential diagnosis includes meningioma, metastasis and lymphoma. There is a limited number of descriptions of chloromas mimicking dural-based masses in the literature. We present preliminary diffusion-weighted MR, perfusion-weighted MR and MR spectroscopy findings of an intracranial myeloid sarcoma.

Isolated recurrence of intracerebral granulocytic sarcoma in acute lymphoblastic leukemia: a case report

Intracranial granulocytic sarcoma (chloroma) may occur rarely in leukemia. A 27-year-old male presented with an isolated recurrence of granulocytic sarcoma manifesting as an intraaxial mass 27 months after complete remission of acute lymphoblastic leukemia. He was admitted due to a severe headache and blurred vision. Brain magnetic resonance imaging demonstrated an enhanced mass which was initially interpreted as an extraaxial tumor in the right temporal region. Because of increased intracranial pressure and the mass effect, open biopsy with surgical resection was performed. The biopsy result indicated that intraaxial lymphoblastic leukemia infiltration had caused CNS relapse. Although granulocytic sarcoma occurs primarily in patients with acute myelogenous leukemia, the authors report a rare case of intraparenchymal granulocytic sarcoma in acute lymphoblastic leukemia.