Abstract
Background Cerebral amyloidoma is a rare form of localised CNS tumefactive amyloid Aβ protein deposition with no evidence of systemic amyloidosis. It is suggested to occur due to misfolding of local proteins and subsequently deposited in tissue.
The distinct radiographic appearance is of a nodular mass focused in the supratentorial periventricular white matter. The lesion demonstrates avid contrast enhancement with perilesional vasogenic oedema, but without significant mass effect given lesion size.
In comparison to more common neurodegenerative amyloid deposition diseases, given the localised nature of the lesion, primary cerebral amyloidoma is potentially curable with aggressive targeted therapy.
Case We describe a forty-five-year-old female referred for assessment of progressive left-sided upper-motor-neurone features, with concern for intracranial glioma on peripheral imaging. She initially presented with left upper limb weakness and paresthesias and over three months developed left lower limb weakness and gait disturbance.
MRI revealed right frontoparietal confluent nodular irregular areas of enhancement most evident in the deep white matter, with extension to the periventricular region and cortex, with vessels transversing the lesion.
Brain biopsy demonstrated amorphous eosinophilic nodular deposits of amyloid, with positive congo-red staining consistent with a diagnosis of lambda light-chain cerebral amyloidoma.
Extensive investigations performed excluded evidence of systemic amyloidosis. Stereotactic radiotherapy was performed with clinical stability over the following eighteen months.
Conclusion This case highlights the rare but important differential of cerebral amyloidoma to be considered in the assessment of CNS mass-like lesions, which presents with a distinct clinico-radiological presentation.
