High grade gliomas associated with abscess: description of a rare case and role of 99mTc-Leukoscan

Aim: Intrasellar or parasellar tumors are among the most common neoplasms that develop abscess as complication, due to direct extension of microbial flora from contiguous sinuses. Abscess formation within a brain tumor is uncommon. We describe an extremely rare case of high grade glioma associated with abscess formation. Material and Methods: The patient was a 50 year old woman with a recent history of epileptic seizures, fever and headache. Haematologic examination demonstrated leukocytosis and elevated C-reactive protein. Magnetic Resonance (MR) obtained before and after contrast medium administration revealed a lesion (> 3 cm in size) in the right temporo-parietal region consistent with brain abscess. Instead, MR spectroscopy (MRS) was conclusive for brain tumor. Patient underwent 99mTc-Leukoscan study of the brain obtained 4 and 24 hours after tracer administration (555 MBq) by dual-headed gamma camera equipped with low-energy high-resolution parallel-hole collimator (LEHRPAR). Scans were performed by planar (anterior, posterior and lateral views; magnification 1, matrix 256x256; 900 seconds per frame) and tomographic images (SPET; magnification 1, matrix 128x128; 180° rotation, a 3° step and shoot technique; 30s per frame). The study showed abnormal and non-homogeneous uptake of the tracer in the right temporo-parietal region corresponding to MR lesion and consistent with brain abscess. Craniotomy was performed and the lesion was totally removed. Histopathological examination permitted a diagnosis of glioblastoma with intralesion abscess. Conclusion: This extremely rare case demonstrated that the presence of brain abscess does not rule out cancer. The diagnosis of brain tumor associated with abscess is particularly difficult by conventional neuroradiological studies. Leukoscan can be useful in the diagnosis of brain abscesses and in differential diagnosis of cyst lesion and/or cystic brain tumor.