Tumefactive demyelinating lesion: experience with two unusual patients

Area of Science:

• Neurology
• Neuroimmunology
• Radiology

Background:

• Tumefactive demyelinating lesions (TDLs) are solitary, large demyelinating lesions that can resemble cerebral neoplasms.
• Accurate differentiation from other intracranial space-occupying lesions is crucial to prevent misdiagnosis and inappropriate interventions.

Observation:

• Two patients presented with unusual initial symptoms: one with recurrent focal seizures and another with homonymous hemianopia.
• Cerebral tumors were the initial suspected diagnoses for both patients.
• Histopathological analysis revealed perivascular lymphocytic infiltrate and foam cells, characteristic of TDLs.

Findings:

• Both patients showed rapid clinical improvement and lesion size reduction following intravenous methylprednisolone administration.
• Epilepsy and homonymous hemianopia are identified as uncommon initial manifestations of TDLs.
• Specific magnetic resonance imaging (MRI) features, such as open-ring or incomplete-ring signs, aided in differentiating TDLs from neoplastic and infectious etiologies.

Implications:

• This case report underscores the diagnostic challenges posed by TDLs, particularly when presenting with atypical symptoms.
• Recognizing the varied clinical presentations and characteristic MRI findings is essential for timely and accurate diagnosis.
• Prompt identification and appropriate treatment with corticosteroids can lead to significant clinical improvement and lesion resolution.