[A case of intracranial infectious granuloma extending into subcutaneous and subdural space].

A case of intracranial infectious granuloma extending into subcutaneous and subdural space mimicking malignant bone tumor was reported. A 49-year-old male was admitted to our service with complaint of left frontal subcutaneous and bone tumor. Neurological examination demonstrated mild disorientation only except for pre-existeng Schizophrenia. CT scan and Gadolinium-enhanced MRI revealed left frontal intraosseous and subdural mass accompanied with remarkable edema. Left frontal bone was destructed by this mass. However, inflammatory sign nor malignant tumor could be observed and left frontal craniotomy and removal of the tumor was performed. The tumor was solid, elastic hard and existing from intra-osseous, epidural and subdural space compressing the cortex. No abscesss cavity could be found. Histological examination revealed infectious granuloma accompanied by remarkable neutrophil infiltration only. The patient showed good post-operative course, and returned to previous condition, pre-existeng Schizophrenia only. Intracranial infectious granuloma extending into subcutaneous and subdural space destructing the bone was rare condition. From literature, similar cases could be found in granuloma arising from osteomyelitis. In this case, destructed bone beneath the epi- and subdural tumor support this route of infection.