Cerebral amyloidomas: Perspective on unusual morphological features.

Aims: Cerebral amyloidomas (CAs) are mass-producing congophilic lesions most commonly due to λ light chain deposits, contrasting them with light chain deposition disease (LCDD) which has non-polarizable, often κ light chain deposition.

Materials and methods: Although usual histological features are well known, we detail 3 recent CAs with unusual morphological findings and review the literature specifically for these features.

Results: Two women, aged 56 and 58 years, had right cerebral white matter CAs. The biopsy of case 1 disclosed congophilic polarizable deposits with prominent dystrophic mineralization as well as scant plasma cells. Case 2 had a CA with significant multinucleated giant cell reaction to the amyloid and additionally contained an area suspicious for marginal zone B-cell lymphoma. Case 3 was a clinically unsuspected CA identified at autopsy in a 75-year-old woman that manifested as several contiguous left frontal lobe white matter erythematous, hyperemic lesions; microscopy showed nodular and concentric amyloid deposits and thick perivascular cuffs of plasma cells. Mass spectrometry proved λ light and α heavy chain amyloid deposits in all 3 cases.

Conclusion: These 3 CA cases illustrate several unusual gross and microscopic features that are discussed in context with the literature.