[A case of brain abscess associated with asymptomatic multiple myeloma]

A 55-year-old male was admitted to our hospital because of confusion and mild weakness of his left arm and leg. His condition had taken a gradual turn for the worse for several months. Computed tomography (CT) demonstrated a mixed density mass with multiple cysts and massive perifocal edema. Magnetic resonance imaging (MRI) demonstrated an irregular-shaped mass with multiple cysts sized 6 x 4 x 6 cm in the temporal lobe, which manifested mixed signal intensity on both the T1 weighted image and the T2 weighted image. MRI also revealed massive perifocal edema and marked midline shift. Gd-DTPA study showed ring-like enhancement. Angiography showed no tumor stain and a suppressed right posterior cerebral artery. A right extended temporo-occipital craniotomy was performed to extirpate the abscess subtotally. The histological examination showed brain abscess and Gram stain of the pus revealed the presence of gram-positive bacilli. The gram-positive bacillus, Corynebacterium only was subsequently cultured from the pus. After the operation his hemiparesis seemed to disappear. In spite of the treatment with multiple intravenous antibiotics, his hemiparesis worsened again. CT and MRI demonstrated recurrence of the brain abscess in the occipital lobe and marked perifocal edema. The second operation was performed and removed all the infected brain tissue with abscess. After the second operation, otorhinological and cardiovascular examinations were carried out, but no causal disease was found. Immunoelectrophoresis (total protein 12.2 g/d/) revealed the peak of M protein. Bone marrow revealed dysplasia of the plasma cell and he was diagnosed as having multiple myeloma that had made him an immunocompromised host.