Background: Central nervous system (CNS) involvement by mycosis fungoides (MF) is rare. As compared to meningeal involvement, intraparenchymal spread is especially rare. It is usually seen in advanced disease in conjunction with lymph node or visceral involvement. However, CNS involvement in the absence of progressive skin lesions or other extracutaneous involvement has been reported rarely in patients with transformed MF.
Method: Case report and review of literature.
Results: A 71-year-old female with long-standing MF developed lymphomatous CNS involvement 10 years after the diagnosis of tumor stage MF. At this time, the patient presented with a transient episode of garbled speech followed by generalized weakness. Computerized tomography scan (CT scan) and magnetic resonance imaging scan (MRI scan) of the head revealed a subcortical lesion in the left temporo-frontal lobe. Cerebrospinal fluid (CSF) examination showed atypical T cells, and brain biopsy confirmed parenchymal involvement by T-cell lymphoma. Meanwhile, a biopsy of a skin lesion showed large-cell transformation. No lymph node or other systemic involvement was noted at this time, and the patient was treated with chemotherapy. Twelve months later, the patient developed recurrent CNS lymphoma with multiple organ involvement and expired soon thereafter.
Conclusions: This case illustrates the importance of awareness of the possibility of CNS involvement by MF, especially in transformed MF. CNS involvement may be the only site of extracutaneous involvement in patients with transformed MF, and mental status changes warrant CNS surveillance for this disease.