Tumefactive demyelinating lesions (TDLs), are a rare demyelinating pathological disease in the central neurological system, which have been proven to be a diagnostic dilemma to neurosurgeons. The clinical presentation and radiographic appearance of these lesions often results in their misdiagnosis as intracranial tumors, such as gliomas, which leads to unnecessary surgical resection and adjunct radiation. In the present study, the clinical and radiographic features of 14 patients with cerebral TDLs who underwent surgical treatment between January 2004 and January 2009 were reviewed and analyzed. The surgical methods used included biopsy and resection, while steroid therapy was indicated when TDLs were confirmed by histopathological analysis. The patients were followed-up and the outcomes were evaluated using the Karnofsky performance scale (KPS). The main clinical presentations included: Hemiplegia (8 cases), increased intracranial pressure (4 cases) and seizures (general in 1 case; partial in 3 cases). On magnetic resonance imaging scans, 12/14 TDL cases demonstrated an isolated local subcortical mass and 6/14 cases (42.9%) demonstrated enhancing veins coursing undistorted through the lesion. The postoperative complications included: Hemiplegia (2 cases) and mortality (1 case). A total of 9 cases underwent microsurgical total resection, and 5 cases received stereotactic biopsy that was followed with high-dose methylprednisolone therapy. The follow-up study demonstrated that 2 cases presented recurrence with multiple sclerosis and the KPS scores for 13/14 patients (92.9%) were ≥80. In conclusion, the clinical and radiographic features of TDLs may help to establish the correct diagnosis prior to surgery, in order to avoid unnecessary resection or adjunctive therapy. Using steroid therapy, the majority of patients with TDLs appeared to achieve satisfactory prognosis.
Demyelinating diseases, are neuropathological entities most frequently observed in the central nervous system with a preferential involvement of the major white matter tracts in a periventricular distribution. These diseases are often difficult to diagnose, since they do not exhibit a typical appearance on magnetic resonance imaging (MRI) scans (
Between January 2004 and January 2009, 14 patients (male, 9; female, 5) with cerebral TDLs were admitted and received surgical treatment at the Department of Neurosurgery of the Beijing Tiantan Hospital. The median age was 24 years (range, 4–51 years). The diagnosis of TDLs was established following pathological analysis. All the patients were examined neurologically and radiologically, including the use of computed tomography (CT) and MRI, prior to and following surgery. The clinical presentations, imaging features and postoperative neurological deficits were recorded. The study was approved by the Ethics Committee of Beijing Tiantan Hospital Affiliated to Capital Medical University (Beijing, China). Written informed consent was obtained from the patients/patients' families.
The surgical approach was decided according to the preoperative diagnosis, which was performed based on the result of medical history, presentations and the radiology examination (CT and MRI scans). When the preoperative diagnosis was considered to be a tumor, craniotomy and microsurgical resection were performed with the aim of complete or partial resection depending on what was feasible. However, in cases where it was not possible to affirm a certain preoperative diagnosis, biopsy was indicated. Biopsy of suspicious lesions was approached stereo tactically in order to minimize tissue injury. In order to improve the positive rate and accuracy of the biopsy, 9–12 targets were selected during stereotactic biopsy. Immunohistopathological analysis was performed for all cases, while the frozen-section procedure was performed only in cases of surgical resection. For the cases that received biopsy, corticosteroid therapy using high-dose methylprednisolone was administered once the diagnosis of TDL was confirmed by histopathological examination. The treatment regimen was as follows: 500–1,000 mg of methylprednisolone within 500 ml of 0.9% NaCl or 5% glucose was administrated intravenously by dropping in 3 h per day for 5 days, which was followed by oral administration of 60–80 mg per day for 1 week. Subsequently, 10 mg methylprednisolone was administered every 5 days to allow withdrawal. Postoperatively, patients with a history of seizure were treated continuously with anticonvulsant therapy until 1–2 years free of seizures was achieved. By contrast, for patients with no history of seizures, 3 months of prophylactic anticonvulsant therapy was routinely administered.
Follow-up study was conducted for all the patients by routine outpatient appointments with neurological and neuroradiological examinations at 3–6 months following discharge, and later by interview, telephone or post. The Karnofsky performance scale (KPS) was used to evaluate the patients' status (
Continuous variables were expressed as the mean ± standard deviation or the median (range), and categorical variables were expressed as proportions.
From the available data of 14 patients, the male-to-female ratio was ~1.8, with a male preponderance (
TDLs were considered to have an acute (4 cases), sub-acute (6 cases) or chronic (4 cases) onset with a duration (defined as the time between onset and admission) of 10 days to 7 years. The main symptoms and signs of the TDLs included the following: Increased intracranial pressure (ICP, 4 cases); local neurological deficits, including hemiplegia (8 cases) and partial aphasia (1 case); seizures, including general (1 case) and local (3 cases). Only 1 case had a history of vaccination and no cases were observed to have an associated infection history.
The radiographic features observed in the 14 TDL cases are listed in
Among the 14 cases examined, 8 cases were misdiagnosed preoperatively as gliomas and 1 case as metastasis (
The follow-up study (range, 17–72 months; mean, 41 months) was successfully completed in all 14 cases, with the exception of 1 mortality case. Among them, 2 resection cases and 2 biopsy cases still had hemiplegia, which was improved compared with that at discharge (
The exact pathogenesis of TDLs is not clearly understood. These lesions are considered to be an isolated middle type between multiple sclerosis and acute-disseminated encephalomyelitis plaques, which are the two common types of demyelinating diseases in the central nervous system (
TDLs may occur at any age groups, but are most commonly observed in adult patients in the second and third decades of their life, as observed in previous studies (
For radiological analysis, MRI is generally the most sensitive imaging technique for depicting a demyelinating disease. However, TDLs present a diagnostic challenge, since they usually presents a subcortical mass in the hemisphere mimicking gliomas as a solitary lesion or metastasis as a few separate lesions (
Clinically, TDLs have proven to be a diagnostic dilemma for neurosurgeons. Among the spectrum of brain tumors, TDLs are misdiagnosed as gliomas, which are common neoplastic lesions. In general, gliomas with increased ICP or local neurological deficits have a longer duration between onset and admission, usually weeks to months. TDLs usually present with a more acute onset and a shorter duration compared with gliomas (
The majority of patients with TDLs have been reported to respond favorably to corticosteroid therapy and not progress to multiple sclerosis (
A previous study has reported that TDLs are usually isolated and rarely progress to typical multiple sclerosis (
In conclusion, TDLs are a rare demyelinating disorder in the central nervous system, resembling brain tumors in their clinical and radiological features and usually responding well to steroid therapy. By improving the understanding on the clinical and radiographical features of these lesions, more patients with TDLs may be correctly diagnosed prior to resection and receive reasonable treatment, which may result in an improved and satisfactory prognosis.
Magnetic resonance imaging scans of tumefactive demyelinating lesion. (A) Non-enhanced axial T2-weighted image demonstrating a lesion located within left basal ganglion area. (B) Enhanced axial T1-weighted image revealing ring-like enhancement. (C) Non-enhanced axial T1-weighted image. of the lesion (D) Enhanced coronal T1-weighted image of the lesion. (E) Enhanced coronal T1-weighted image of the lesion. The arrows indicate the area of the lesion.
Clinical presentations of 14 patients with tumefactive demyelinating lesions.
Clinical presentation | Cases, n | Proportion, % |
---|---|---|
Severity | ||
Acute | 4 | 28.6 |
Subacure | 6 | 42.8 |
Chronic | 4 | 28.6 |
Symptoms and sings | ||
ICP | 4 | 28.6 |
Local neurological deficits | ||
Hemiplegia | 8 | 57.2 |
Partial aphasia | 1 | 7.1 |
Seizures | ||
General | 1 | 7.1 |
Local | 3 | 21.4 |
Vaccination history | 1 | 7.1 |
Infection history | 0 | 0.0 |
ICP, increased intracranial pressure.
Radiographic features of tumefactive demyelinating lesions patients.
Feature | Cases, n | Proportion, % |
---|---|---|
Solitary lesions | ||
Frontal lobe | 3 | 21.4 |
Temporal lobe | 4 | 28.6 |
Parietal lobe | 3 | 21.4 |
Insular lobe | 1 | 7.2 |
Basilar ganglia area | 1 | 7.2 |
Multiple lesions |
||
Frontal lobe + parietal lobe | 1 | 7.2 |
Frontal lobe + pons | 1 | 7.2 |
Computed tomography scan | ||
Hypodense |
9 | 64.3 |
Heterogeneous density | 5 | 35.7 |
Magnetic resonance imaging |
||
Local subcortical mass | 12 | 85.7 |
Heterogeneous intensity | 2 | 14.3 |
Relative sharp margin |
6 | 42.9 |
Poor defined margin | 8 | 57.1 |
Variable enhancement | ||
Patchy | 5 | 35.7 |
Open ring-like | 6 | 42.9 |
Ring-like | 3 | 21.4 |
Vein coursing | 6 | 42.9 |
Size range, 2–5 cm.
Well-defined margin and little surrounding edema.
Hypointense on T1-weighted images; hyperintense on T2-weighted and fluid-attenuated inversion recovery images.
Light to moderate surrounding edema.
Diagnosis of patients with tumefactive demyelinating lesions.
Diagnosis | Cases, n | Proportion, % |
---|---|---|
Certain diagnosis | ||
Gliomas | 8 | 57.1 |
Metastasis | 1 | 7.1 |
No certain diagnosis | 5 | 35.8 |
Therapy methods and outcomes of patients with tumefactive demyelinating lesions.
Parameter | Cases, n | Proportion, % |
---|---|---|
Resection | ||
Total | 8 | 57.1 |
Subtotal (frozen-section) | 1 | 7.1 |
Intracranial hypotension | 4 | 28.6 |
Complication | ||
Hemiplegia | 2 | 14.3 |
Mortality | 1 | 7.1 |
Biopsy | 5 | 35.7 |
Symptoms and signs | ||
Improved | 4 | 28.6 |
Relieved | 2 | 14.3 |
Follow-up study.
Outcome | Cases, n (%) | Notes |
---|---|---|
Complications | ||
Hemiplegia | 4 (28.6) | 2 resection cases; 2 biopsy cases |
Seizures | 4 (28.6) | 2 cases improved; 2 cases achieved total seizure-control |
Aphasia | 1 | Totally relieved 3 months after biopsy |
Recurrent cases | 2 (14.3) | Identified by MRI, 26 and 51 months postoperatively |
KPS | ||
100 | 7 (50.0) | – |
90 | 3 (21.4) | – |
80 | 3 (21.4) | – |
0 | 1 (7.1) | Mortality |
MRI, magnetic resonance imaging; KPS, Karnofsky performance scale.