Clinical Neuropathology最新文献

Traumatic brain injury (TBI) is a leading cause of morbidity and mortality worldwide. TBI ranges from mild to severe and is a recognized risk factor for later neurodegenerative conditions including chronic traumatic encephalopathy (CTE), Alzheimer disease (AD) and Parkinson disease (PD). The development of CTE is typically associated with repetitive exposure to mild TBI (mTBI), while a single moderate-to-severe TBI is considered a risk factor for AD and PD. Polypathology is common, and the lines between these conditions post TBI can be somewhat blurred. The mechanisms through which TBI leads to future neurodegeneration are not well understood. Heterogeneity and distance from the injury or injuries and individual genetic and environmental factors make clinical studies difficult. We present the case of an 82-year-old man who died 4 years after developing a phenotypically mixed dementia with neuropsychiatric features and parkinsonism. He had a remote history of a severe TBI 40 years prior, following a road traffic accident which caused a large right frontal injury, requiring neurosurgical intervention. Post-mortem neuropathological examination demonstrated abnormal phosphorylated-Tau (p-Tau), beta-amyloid plaques (Aβ) and α-synuclein deposition. Spatial immunohistochemical analysis demonstrated increased perivascular accumulation of p-Tau with blood-brain barrier (BBB) disruption at the site of injury, which decreased with distance from the injury site. The appearances are suggestive of initial vascular disruption with persisting BBB disruption as a driver of the pathology.

Pick's disease (PiD) is a rare form of frontal temporal lobar degeneration. The pathognomonic feature is atrophy of the frontotemporal lobes and intraneuronal deposits of 3R-τ inclusions, the Pick body. Corticobasal syndrome (CBS) is an atypical parkinsonian syndrome with a heterogeneous spectrum of underlying pathologies. We report a case of clinically diagnosed CBS with a post-mortem diagnosis of PiD and conduct a clinicopathological review of the literature on this unusual presentation.

Cerebral amyloid angiopathy (CAA) is the most frequent cause of lobar hemorrhages in the brains of elderly individuals. It is characterized by the deposition of amyloidogenic proteins in the vessel wall of leptomeningeal and/or intracerebral blood vessels. Different proteins can cause CAA. Most frequently, the amyloid β protein (Aβ) is found to be deposited in CAA and indicates a link to Alzheimer's disease, because Aβ is known to be deposited in amyloid plaques characteristic of Alzheimer's disease. Among other proteins that can also cause CAA, transthyretin (TTR) is the most important one because TTR amyloidosis can be successfully treated. Therefore, it is essential to diagnose TTR-related CAA even in biopsies taken in the context of cerebral hematoma evacuations if possible. The current "Boston criteria version 2.0" for the diagnosis of CAA highlight the importance of autopsy for the definite diagnosis of CAA and biopsies for the diagnosis of probable CAA. Here, we discuss the implications of Aβ-related and non-Aβ-related forms of CAA for their current diagnostic relevance also in the context of neurodegenerative diseases as well as the implications of the Boston criteria version 2.0 for neuropathological diagnosis.

Tumor-to-tumor metastasis (TTM) is a process where one tumor metastasizes to another tumor. It is an exceedingly rare phenomenon, particularly in the central nervous system, where it most commonly occurs with meningiomas as the recipient. Herein, we present a case of tumor-to-tumor metastasis of an adenocarcinoma to a glioblastoma in a 75-year-old female. The patient had a history of high-grade ductal carcinoma in situ of the breast 8 years prior, treated with lumpectomy and radiation. She presented with a left fronto-parietal mass. Histologically, the lesion showed a glioblastoma, IDH-wildtype, WHO grade 4, associated with a metastatic adenocarcinoma (positive for estrogen receptor, progesterone receptor, and mammaglobin), suggesting a breast primary. The patient passed away 5 months after surgery. Involvement of glioblastoma by TTM is especially rare; only 1 case of TTM to glioblastoma is thus far reported in the English literature. The mechanism by which TTM occurs is poorly understood. TTM may be the first presentation of an occult malignancy and warrants thorough clinical, laboratory, and imaging investigation.

Purpose: To characterize expression of factors relevant for Ras signaling and developmental factors in a large series of peripheral nerve sheath tumors (PNST) obtained from patients with neurofibromatosis type 1 (NF1).

Materials and methods: Tissue micro-array technique was applied to study 520 PNST of 385 NF1 patients by immunohistochemistry for mTor, Rho, phosphorylated MEK, Pax7, Sox9, and periaxin expression. PNST comprised cutaneous neurofibroma (CNF) (n = 114), diffuse neurofibroma (DNF) (n = 109), diffuse plexiform neurofibroma (DPNF) (n = 108), plexiform neurofibroma (PNF) (n = 110), and malignant PNST (MPNST) (n = 22).

Results: All proteins examined showed highest expression levels/highest frequency of expression in MPNST. Benign PNF with potential for malignant dedifferentiation expressed mTor, phosphorylated MEK, Sox9, and periaxin significantly higher/more frequently than other benign neurofibroma subtypes.

Conclusion: In NF1-associated PNST, expression of proteins involved in Ras-signaling and development is upregulated not only in MPNST, but also in benign PNF with the potential for malignant dedifferentiation. The differences in protein expression may provide clues for understanding the therapeutic effects of substances applied for reduction of PNST in NF1.

Molecular characterization has become a key diagnostic tool for the classification and grading of primary brain tumors. Molecular markers, such as isocitrate dehydrogenase (IDH) mutation status, 1p/19q codeletion, methylation of the O(6)-methylguanine-DNA methyltransferase (MGMT) promoter, or CDKN2A/B homozygous deletion discriminate different tumor entities and grades, and play a crucial role for treatment response and prognosis. In recent years, magnetic resonance imaging (MRI), whose main functions has been to detect a tumor, to provide spatial information for neurosurgical and radiotherapy planning, and to monitor treatment response, has shown potential in assessing molecular features of gliomas from image-based biomarkers. As an outstanding example, numerous studies have proven that the T2/FLAIR mismatch sign can identify IDH-mutant, 1p/19q non-codeleted astrocytomas with a specificity of up to 100%. For other purposes, multiparametric MRI, often coupled with machine learning methods, seems to achieve the highest accuracy in predicting molecular markers. Relevant future applications might be anticipating changes in the molecular composition of gliomas and providing useful information about the cellular and genetic heterogeneity of gliomas, especially in the non-resected tumor parts.