Substantia Nigra decreased pigmentation in Parkinson Disease

The substantia nigra (literal translation: “black substance”) is a portion of the midbrain that contains pigmented dopamine-producing neurons.  Degeneration of these cells causes relative depigmentation the substantia nigra, representing a finding that is typical of Parkinson Disease, but may also be present in other neurodegenerative disorders such as Alzheimer Disease. Shown here is the basal... Continue Reading →

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Periventricular Leukomalacia (PVL)

Periventricular Leukomalacia (PVL) is a type of brain damage that affects fetuses and premature babies. At this stage of brain  development, the white matter surrounding the ventricles is particularly vulnerable to hypoxic (lack of oxygen) or ischemic (lack of blood flow) injury for a variety of reasons, including high metabolic demand in a location that... Continue Reading →

Dura Metastasis: Hepatocellular Carcinoma

The most common tumors found in the central nervous system and dura (i.e. the dense fibrous covering that envelops the brain) are those that have traveled from other body sites in a process called metastasis.  Depicted here is hepatocellular carcinoma (HCC), a cancer of liver cells, that has metastasized to the dura overlying the anterior pole of the right frontal lobe. Microscopically, the neoplastic liver... Continue Reading →

Globose Neurofibrillary Tangle

Neurodegenerative diseases commonly have abnormal protein inclusions that ultimately contribute to neuron death.  One such example is abnormally hyperphosphorylated tau protein, the major component of neurofibrillary tangles (NFTs), which are a key microscopic feature of Alzheimer Disease and lesser known neurodegenerative diseases, such as Frontotemporal Lobar Degeneration (FTLD).  Like water in a vase, an NFT will assume the shape of the cell in which it arises.  For example, the classic... Continue Reading →

Cortical Atrophy in an Elderly Person (90 years old)

A normal adult loses about 0.2% of brain volume every year after middle age.  Compared to young and middle-aged adults, the brains of the elderly have comparatively widened sulci, narrowed gyri, a thin cortical ribbon, and enlarged ventricles due to progressive brain volume loss, which, clinically, may contribute slower processing speed for cognitive tasks and other changes.  Microglia-mediated synaptic pruning and other etiologies for decreasing cortical volume in the... Continue Reading →

Classic Imaging: Cyst with an Enhancing Mural Nodule

For many years the only mechanism for observing gross pathologic features of CNS neoplasms was to examine brains extracted after death.  However, advancements in imaging technology now allow providers to observe typical gross neuropathological findings in the brains of living patients.  Some brain tumors have characteristic MRI findings, an example of which is a cyst... Continue Reading →

Verocay Bodies in Schwannoma

Schwannomas are peripheral nerve sheath tumors that arise from cells that myelinate peripheral nerve axons called Schwann cells. A classic histologic finding in schwannomas are Verocay bodies (arrows), which consist of short palisades of tumor cell nuclei separated by eosinophilic anucleate bands of tumor cell processes.  Verocay bodies are often more prominent in schwannomas that arise in the setting of a... Continue Reading →

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