Abscess Within a Brain Metastasis

     Wai Pui Ng and Andres Lozano

Abstract:   Background: Neoplastic metastases to the cerebellum are a frequent complication in patients with carcinoma. However, the co-existence of an abscess within a CNS metastasis is a rare event. Methods: We report the case of a 79-year-old woman with two cerebellar abscesses within metastatic lesions in the cerebellum. She presented with a rapidly progressing syndrome characterized by elevated intracranial pressure and cerebellar findings. Results: At surgery, a purulent exudate within discrete metastatic tumours was identified. Pathological and microbiological examinations confirmed the coexistence of an abscess within a metastatic carcinoma. Significance and Conclusion: The radiological diagnosis of intracranial abscesses and metastases can be non-specific and brain imaging may not reliably identify both processes when they coexist. Furthermore, brain metastases often contain liquefied material which can be mistaken for tissue necrosis rather than an infectious process. It is impor-tant to be aware that a brain metastasis can also be infected. Therefore, acquisition of lesional tissue for both pathological and microbiological examinations is essential for accurate diagnosis and to direct optimal therapy in situations where the intracranial lesion could be either an abscess or a metastatic deposit.

Can. J. Neurol. Sci. 1996; 23: 300-002