Spontaneous regression of an intracerebral lymphoma (ghost tumor) in a liver-engrafted patient.

Posttransplantation lymphoproliferative disorder involving the central nervous system is a rare and serious complication associated with solid organ transplantation. We report a liver transplant recipient who noticed unbalance, dizziness, and headache 30 months after transplantation. Magnetic resonance imaging (MRI) showed a space-occupying lesion in the corpus callosum and adjacent parenchyma of the left hemisphere. In the following month, the neurological symptoms and the MRI findings regressed without any treatment. Four months later the patient developed a left-sided hemiparesis. MRI now revealed a considerable increase of the known lesion and new lesions in other locations. Stereotactic biopsy showed a B-cell non-Hodgkin lymphoma of high malignancy. A spontaneous regression of cerebral lymphoma is possible, even in immunosuppressed patients. Hence, this diagnosis must not be dismissed if there is spontaneous regression of a lesion in the MRI or an amelioration of the clinical symptoms. Owing to the high mortality rate associated with this disease, prompt pathologic diagnosis is required to initiate appropriate therapy.