[A case of an intracerebral mass lesion consisting of traumatic granulation tissue]

We reported a rare case of an intracerebral granulomatous lesion accompanying severe edema formation in the healing stage of traumatic brain contusions. A 44-year-old male patient came to our outpatient clinic due to progressing headache and nausea. Upon computed tomographic examination, a low density mass with strong surrounding edema was detected at the right frontal base. Magnetic resonance images revealed a high intensity mass on both T1- and T2-weighted images at the right frontal base. Upon intravenous injection of a contrast agent, this lesion exhibited multifocal marginal contrast enhancement. Two additional small enhanced mass lesions were detected at the tip of the right temporal lobe and the medial portion of the left temporal lobe. We tentatively diagnosed it as a right frontal brain tumor and attempted the total removal of the right frontal mass. Unexpectedly, pathological diagnosis was intracerebral granulation tissue associated with accumulation of hemosiderin-laden macrophages and capillary wall thickening. In addition, there was no reactive gliosis. We speculated on the pathogenesis of intracerebral granulation tissue as follows. Since the patient was a heavy drinker and often fell down when he was drunk, it is likely that he might be suffering from intracerebral hematomas due to traumatic contusions. This assumption may be supported by the fact that an old subdural hematoma was observed during the operation and the radiological examination revealed multiple lesions. The gathering and proliferation of mesenchymal cells possibly derived from blood circulation probably began at the site of the damaged brain tissue, thus forming intracerebral granulation tissue.(ABSTRACT TRUNCATED AT 250 WORDS)