Table of Contents
Washington University Experience | NEURODEGENERATION | Lewy Body Disease (LBD) | 4 LBD - Gross Pathology - LBD-Dementia with AD | 2B Case 2 Denouement
Not shown: Frontal lobe sections show occasional H&E stained neuritic/diffuse plaques which are confirmed by beta-amyloid immunohistochemistry; senile plaques consist of diffuse (the majority), compact and neuritic (scattered) plaques. PHF1 immunohistochemistry identifies a significant population of neurofibrillary tangles and neurites in the frontal lobe. Rare cortical Lewy bodies are also identified. The hippocampal formation contains a remarkable number of large Hirano bodies as well as moderate numbers of PHF1 tau neurofibrillary tangles and moderate and occasional senile plaques in the entorhinal cortex and Ammon's horn, respectively. TDP-43 containing neurons are not identified in the hippocampal sections. Lewy bodies are numerous in entorhinal cortex and Ammon's horn, confirmed by immunohistochemistry for pSYN. The anterior cingulate gyrus contains numerous cortical Lewy bodies and neurites, confirmed by a-pSYN immunostaining. The H&E stained occipital lobe also demonstrates scattered senile plaques. There is evidence for dropout of pigmented neurons in the rostral prolongation of the substantia nigra into the ventral thalamus. Cortical Lewy bodies are seen in the amygdala, confirmed by a p-aSYN immunostaining. Neurons are significantly decreased in the substantia nigra with increased astrocytes, neuromelanin in macrophages and free in the neuropil. Lewy bodies are visible in H&E stained substantia nigra but immunohistochemistry for a-synuclein shows substantially increased numbers in neuronal perikarya and free in the neuropil. Lewy neurites are also identified. The locus ceruleus similarly has decreased numbers of pigmented neurons, presence of Lewy bodies and neurites. Neuro Final Diagnosis: Diffuse Lewy Body Disease (Dementia with Lewy bodies); Alzheimer Disease Neuropathologic Change (A3, B3, C1, see comment) ---- Neuro Diagnosis Comment: This case displays alpha-synuclein-positive inclusions in the form of Lewy bodies and Lewy neurites in brainstem, limbic and neocortical areas accompanied by substantial neuron loss. The distribution of Lewy bodies is consistent with a neocortical stage of DLB. In the staging of Lewy body pathology in Parkinson disease according to Braak et al., this case is stage 6 (range: 1-6). Pathologic changes in this case also include numerous beta-amyloid plaques (mostly diffuse), frequent neurofibrillary tangles and scattered neuritic plaques. According to NIA-AA grading system, this case is rated: A3, B3, C1; where A = beta-amyloid plaque stage; B = neurofibrillary tangle stage, and C = neuritic plaque stage. Thus, it would appear that both Alzheimer's disease and Diffuse Lewy Body Disease (also known as Dementia with Lewy bodies) contributed to this patient's dementia.
