Multifocal hemosiderin depositions on T2*-weighted magnetic resonance imaging in a patient with pathology-proven systemic diffuse large B-cell lymphoma

BACKGROUND: Intracranial hemorrhage in central nervous system lymphoma is extremely rare. T2*-weighted gradient-echo magnetic resonance imaging is of particularly use in detecting silent hemorrhage as hypointense signals due to the deposition of paramagnetic hemosiderin or mineralization. Multifocal hemosiderin depositions caused by chronic silent hemorrhage have not yet been identified in patients with central nervous system involvement of systemic lymphoma. We present an unexpected radiographic feature on T2*-weighted gradient-echo magnetic resonance imaging in a patient with central nervous system involvement of pathologically confirmed systemic diffuse large B-cell lymphoma. CASE PRESENTATION: A 56-year-old woman presented with lower extremities weakness and progressive cognitive decline for four months. Conventional brain magnetic resonance imaging demonstrated multiple lesions with hypointensities on T1-weighted images and hyperintensities on T2-weighted images and fluid attenuated inversion recovery in both hemispheres. She was then transferred to our hospital. Neurological examination showed impaired cognitive functions. Contrast-enhanced magnetic resonance imaging revealed irregular spotty enhancement within the lesions. T2*-weighted gradient-echo magnetic resonance imaging revealed diffuse hemosiderin depositions with hypointensities mostly adjacent to the cortex, which are not compatible with the lesions visualized on T1-weighted images. Whole body positron emission tomography/computed tomography scanning showed multiple hyper-metabolic foci in the pelvic cavity and the spleen. The pathological diagnosis of the biopsy specimen was consistent with diffuse large B-cell lymphoma. CONCLUSION: This is the first report of pathologically confirmed case of CNS involvement of systemic diffuse large B-cell lymphoma with multifocal silent hemosiderin depositions detected by T2*-weighted gradient-echo magnetic resonance imaging. Even though uncommon, our report offers an insight that CNS lymphoma could present with multifocal silent hemosiderin depositions on T2*-weighted gradient-echo magnetic resonance imaging. Further studies were expected for exploring the association between this radiologic feature and systemic lymphoma and their underlying mechanisms.