Clinical presentation and extent of resection impacts progression-free survival in spinal ependymomas.

PURPOSE: Primary treatment of spinal ependymomas involves surgical resection, however recurrence ranges between 50 and 70%. While the association of survival outcomes with lesion extent of resection (EOR) has been studied, existing analyses are limited by small samples and archaic data resulting in an inhomogeneous population. We investigated the relationship between EOR and survival outcomes, chiefly overall survival (OS) and progression-free survival (PFS), in a large contemporary cohort of spinal ependymoma patients. METHODS: Adult patients diagnosed with a spinal ependymoma from 2006 to 2021 were identified from an institutional registry. Patients undergoing primary surgical resection at our institution, ≥ 1 routine follow-up MRI, and pathologic diagnosis of ependymoma were included. Records were reviewed for demographic information, EOR, lesion characteristics, and pre-/post-operative neurologic symptoms. EOR was divided into 2 classifications: gross total resection (GTR) and subtotal resection (STR). Log-rank test was used to compare OS and PFS between patient groups. RESULTS: Sixty-nine patients satisfied inclusion criteria, with 79.7% benefitting from GTR. The population was 56.2% male with average age of 45.7 years, and median follow-up duration of 58 months. Cox multivariate model demonstrated significant improvement in PFS when a GTR was attained (p <.001). Independently ambulatory patients prior to surgery had superior PFS (p <.001) and OS (p =.05). In univariate analyses, patients with a syrinx had improved PFS (p =.03) and were more likely to benefit from GTR (p =.01). Alternatively, OS was not affected by EOR (p =.78). CONCLUSIONS: In this large, contemporary series of adult spinal ependymoma patients, we demonstrated improvements in PFS when GTR was achieved.

Focal cortical dysplasia is a frequent coexistent pathology in patients with Rasmussen's encephalitis.

INTRODUCTION: Rasmussen's encephalitis (RE) is a rare, predominantly pediatric epilepsy disorder of unknown etiology. It classically affects one of the cerebral hemispheres and histologically shows cortical chronic inflammation, gliosis, and neuronal loss. The etiopathogenesis of RE remains unknown, with genetic, infectious, and autoimmune factors all speculated to play a role. Although the histologic findings in RE are well described, few studies have investigated a large cohort of cases looking for the coexistence of RE with focal cortical dysplasia (FCD). DESIGN: The study is a retrospective review of RE patients who underwent surgical resection of brain tissue between 1979 and 2021. Relevant patient history was retrieved, and available histologic slides were reviewed. The histologic severity of RE was described according to the Pardo criteria. In cases where FCD was present, the observed patterns of FCD (namely Ia, Ib, IIa, IIb, etc.) were described using the International League Against Epilepsy (ILAE) classification. RESULTS: Thirty-eight resection specimens from 31 patients formed the study cohort. Seventeen patients (54.8 %) were male; average age at surgery was 8 years (range: 2-28 years). Twenty-seven resection specimens (71.1 %) from 23 patients (74 %) showed evidence of coexistent FCD. Most cases with FCD resembled the ILAE type Ib (n = 23) pattern. Cases of RE that did not show FCD were either Pardo stage 1 (n = 5) or 4 (n = 6), with all Pardo stage 2 and 3 cases demonstrating FCD. CONCLUSIONS: FCD was found in most patients with RE (74 %). The most observed pattern of FCD was ILAE Ib.

Tumor-to-tumor metastasis of an adenocarcinoma to a glioblastoma with review of the literature on tumor-to-tumor metastasis to gliomas.

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.

IDH mutations in older patients with diffuse astrocytic gliomas.

In 2016, the World Health Organization recommended that isocitrate dehydrogenase (IDH) mutation status be included in the classification of diffuse astrocytic gliomas. IDH mutations are part of the current definition of oligodendrogliomas and are predictive of a better outcome in diffuse astrocytic gliomas. A few studies, examining the role of routine IDH testing in older patients, came to differing conclusions and made differing recommendations regarding a routine IDH testing algorithm with respect to patient age. The purpose of this study was to examine IDH mutations in a series of diffuse astrocytic gliomas [N = 381; 53 diffuse astrocytomas (WHO grade II), 66 anaplastic astrocytomas (WHO grade III) and 262 glioblastomas (WHO grade IV)], paying particular attention to age of patient and any relationship between age and IDH status. IDH status was evaluated by immunohistochemistry with IDH-1 (R132H) antibody and if negative staining was noted, followup polymerase chain reaction (PCR) testing assessing for IDH-1 and IDH-2 mutations was performed. Overall, IDH mutations were discovered in 50.1% of grade II tumors, 54.4% of grade III tumors and 15.1% of grade IV tumors. Of tumors studied, 224 tumors (58.8%) arose in patients 55 years or older. Higher rates of IDH mutations were observed in the patient group less than 55 years of age versus those 55 years or older. By PCR testing in patients 55 years or older, non IDH-1 (R132H) mutations were noted in 0/4 grade II tumors, 3/11 grade III tumors and 26/37 grade IV tumors. The results of this study suggest that although IDH mutations in diffuse astrocytic gliomas are more frequently encountered in patients less than 55 years of age, a significant subset of older patients have mutations that would not be discovered on routine immunohistochemistry and therefore, followup PCR testing is recommended for all patients whose tumors are negative by immunohistochemistry.

1p/19q co-deleted fibrillary astrocytomas: Not everything that is co-deleted is an oligodendroglioma.

The presence of chromosome 1p/19q co-deletion is one of the hallmark required criteria for the diagnosis of oligodendroglioma, using the 2016 World Health Organization (WHO) Classification of Tumours of the Central Nervous System. Descriptions in the literature of astrocytomas, primarily glioblastomas, demonstrating partial losses on one or the other chromosome have been described. The significance of these small deletions is uncertain. Only rarely have cases of fibrillary astrocytoma been described as having co-deletion, which may potentially cause diagnostic confusion with oligodendroglioma. The goal of this study is to examine a large number of fibrillary astrocytomas to document how often 1p/19q co-deletions are present by Fluorescent In Situ Hybridization (FISH) testing (the testing method of choice in many institutions) and to evaluate what other markers may be helpful in avoiding misdiagnosis. This study is a retrospective evaluation of 359 fibrillary astrocytomas (55 grade II, 62 grade III and 242 grade IV) encountered between June 2016 and June 2019, we identified 11 tumors (3.1%) that had 1p/19q co-deletion by FISH testing. The clinical and pathologic features of these cases were reviewed. The 11 cases with co-deletion included 5 females who ranged in age from 37 to 86 years (median 63 years). Tumors arose in the temporal lobe in 5 patients, frontal lobe in 2, parietal lobe in 2, occipital lobe in 1, and cerebellum in 1. Final diagnoses included glioblastoma in 8 patients, anaplastic astrocytoma in 2, and diffuse astrocytoma in 1. Only 1 case (anaplastic astrocytoma) demonstrated evidence of IDH-1 immunoreactivity; none of the other 10 tumors showed evidence of an IDH1/2 mutation by PCR testing. Four tumors demonstrated p53 immunostaining of 30% or more. ATRX mutation as evidenced by loss of staining was observed in only 2 cases. Evidence of EGFR amplification by FISH testing was noted in 5 cases. Of particular note in the one case that demonstrated both 1p/19q co-deletion and an IDH-1 mutation, LOH testing was done and showed only partial losses on both chromosomes. Additionally, this tumor also demonstrated evidence of ATRX and p53 mutations by immunohistochemistry. In conclusion, co-deletions were noted in a minority of astrocytomas (3.1% of cases in the current study). Only 1 of 11 of these cases also demonstrated evidence of an IDH mutation, potentially raising differential diagnostic confusion with oligodendroglioma. Use of LOH 1p/19q testing, if available, or other markers such as ATRX, p53 and EGFR may be helpful in avoiding misclassification of such tumors as oligodendroglioma.

Pediatric clear cell meningioma involving the middle cranial fossa in the context of NF2 and SMARCE1 mutations.

Meningiomas are an uncommon entity in children and adolescents. <30 cases of pediatric clear cell meningioma (CCM), a World Health Organization (WHO) Grade II tumor, have been reported in the literature. These tumors are more likely to recur than the more common WHO Grade I meningiomas, especially with incomplete surgical resection. CCMs are most commonly found in the spine and posterior cranial fossa. Recently, SMARCE1 mutations have been linked to the development of CCM. To evaluate the progression of pediatric CCM in the context of emerging genetic knowledge, we reviewed all 45 cases of CCM at our institution for a 23 year period (1997-2019) to identify pediatric cases. Forty-four of the tumors arose in adults from age 34-81 years. The one pediatric case originally presented at age 4 years; the patient was found to have a CCM in the left cavernous sinus projecting into the posterior fossa, associated with a novel germline SMARCE1 mutation and somatic NF1 and DMD mutations. After two years, the patient had a recurrence of the tumor and underwent a second resection. This is the 5th reported case of CCM in the middle cranial fossa, and the only recurrent case, as well as the only reported case of recurrent pediatric CCM associated with a germline SMARCE1 mutation. Further study of the natural history of tumors associated with germline SMARCE1 loss could potentially inform prognosis.

Evaluation of deeper levels in initially negative temporal artery biopsies and likelihood of a positive result.

Giant cell arteritis is a vasculitis that affects large- and medium-sized vessels in patients over the age of 50 years. The demonstration of granulomatous arteritis is the criterion standard to establish a definitive diagnosis. However, temporal arteritis is known to discontinuously involve the artery, and there is no standardization of the number of sections which should be examined in a length of sampled artery. The goal of the study is to determine, if by examining additional sections from temporal artery (TA) biopsy cases initially interpreted as negative, do we uncover cases of vasculitis. We conducted a retrospective review of the clinical and histologic features of 75 consecutive temporal artery biopsy cases. Our findings showed that the vast majority (94%) of cases that were biopsy "proven" to be negative for temporal arteritis on initial examination remained negative after examination of all subsequent deeper levels (median of 337 total levels examined). These cases were less likely to show classical GCA signs and symptoms and typically presented at a younger age than the biopsy-positive cases. However, 4 (6%) of the initially "biopsy-negative" cases did turn out to be positive on deeper levels, with 56, 109, 346, and 590 total levels examined, respectively. At least 2 of these 4 patients did not receive prednisone or were weaned off prednisone treatment and experienced persistent/recurrent GCA symptoms. We conclude that routine sampling may miss the diagnosis in a subset of cases and in some cases, sectioning deeper into the paraffin block may be warranted.

Brain microvascular pathology in Susac syndrome: an electron microscopic study of five cases.

Susac syndrome is a rare, immune-mediated disease characterized by encephalopathy, branch retinal artery occlusion, and hearing loss. Herein, we describe the electron microscopic findings of three brain biopsies and two brain autopsies performed on five patients whose working clinical diagnosis was Susac syndrome. In all five cases, the key findings were basement membrane thickening and collagen deposition in the perivascular space involving small vessels and leading to thickening of vessel walls, narrowing, and vascular occlusion. These findings indicate that Susac syndrome is a microvascular disease. Mononuclear cells were present in the perivascular space, underlining the inflammatory nature of the pathology. Though nonspecific, the changes can be distinguished from genetic and acquired small vessel diseases. The encephalopathy of Susac syndrome overlaps clinically with degenerative and infectious conditions, and brain biopsy may be used for its diagnosis. Its vascular etiology may not be obvious on light microscopy, and electron microscopy is important for its confirmation.

IDH-1 polymorphisms in pilocytic astrocytomas.

As of 2016, isocitrate dehydrogenase (IDH)-1 and IDH-2 mutations are part of the definition of an oligodendroglioma and may be seen in a significant subset of grade II-IV fibrillary astrocytomas. Reports of IDH-1 and IDH-2 alterations in pilocytic astrocytomas have been rare. This study reports two cases of pilocytic astrocytomas which harbored IDH-1 polymorphisms (G105G) (c.315C > T) discovered on polymerase chain reaction (PCR) testing and sequencing. The first was encountered in a 21-year-old male with a right orbital frontal pole mass. The second occurred in a 19-year-old female with a right frontal tumor. Neither tumor stained with antibody to IDH-1 (R132H). No BRAF V600E immunostaining, minimal p53 staining (<5%) and no loss of ATRX staining was noted in both cases. The significance of the IDH-1 findings at this juncture is uncertain. Misdiagnosis of the tumor as a fibrillary astrocytoma or oligodendroglioma due to the presence of an IDH alteration should be avoided.

Quantitative positron emission tomography-guided magnetic resonance imaging postprocessing in magnetic resonance imaging-negative epilepsies.

OBJECTIVE: Detection of focal cortical dysplasia (FCD) is of paramount importance in epilepsy presurgical evaluation. Our study aims at utilizing quantitative positron emission tomography (QPET) analysis to complement magnetic resonance imaging (MRI) postprocessing by a morphometric analysis program (MAP) to facilitate automated identification of subtle FCD. METHODS: We retrospectively included a consecutive cohort of surgical patients who had a negative preoperative MRI by radiology report. MAP was performed on T1-weighted volumetric sequence and QPET was performed on PET/computed tomographic data, both with comparison to scanner-specific normal databases. Concordance between MAP and QPET was assessed at a lobar level, and the significance of concordant QPET-MAP+ abnormalities was confirmed by postresective seizure outcome and histopathology. QPET thresholds of standard deviations (SDs) of -1, -2, -3, and -4 were evaluated to identify the optimal threshold for QPET-MAP analysis. RESULTS: A total of 104 patients were included. When QPET thresholds of SD = -1, -2, and -3 were used, complete resection of the QPET-MAP+ region was significantly associated with seizure-free outcome when compared with the partial resection group (P = 0.023, P < 0.001, P = 0.006) or the no resection group (P = 0.002, P < 0.001, P = 0.001). The SD threshold of -2 showed the best combination of positive rate (55%), sensitivity (0.68), specificity (0.88), positive predictive value (0.88), and negative predictive value (0.69). Surgical pathology of the resected QPET-MAP+ areas revealed mainly FCD type I. Multiple QPET-MAP+ regions were present in 12% of the patients at SD = -2. SIGNIFICANCE: Our study demonstrates a practical and effective approach to combine quantitative analyses of functional (QPET) and structural (MAP) imaging data to improve identification of subtle epileptic abnormalities. This approach can be readily adopted by epilepsy centers to improve postresective seizure outcomes for patients without apparent lesions on MRI.

Expression of LC3B and FIP200/Atg17 in brain metastases of breast cancer.

BACKGROUND: Macroautophagy/autophagy is considered to play key roles in tumor cell evasion of therapy and establishment of metastases in breast cancer. High expression of LC3, a residual autophagy marker, in primary breast tumors has been associated with metastatic disease and poor outcome. FIP200/Atg17, a multi-functional pro-survival molecule required for autophagy, has been implicated in brain metastases in experimental models. However, expression of these proteins has not been examined in brain metastases from patients with breast cancer. METHODS: In this retrospective study, specimens from 44 patients with brain metastases of infiltrating ductal carcinoma of the breast (IDC), unpaired samples from 52 patients with primary IDC (primary-BC) and 16 matched-paired samples were analyzed for LC3 puncta, expression of FIP200/Atg17, and p62 staining. RESULTS: LC3-puncta+ tumor cells and FIP200/Atg17 expression were detected in greater than 90% of brain metastases but there were considerable intra- and inter-tumor differences in expression levels. High numbers of LC3-puncta+ tumor cells in brain metastases correlated with a significantly shorter survival time in triple-negative breast cancer. FIP200/Atg17 protein levels were significantly higher in metastases that subsequently recurred following therapy. The percentages of LC3 puncta+ tumor cells and FIP200/Atg17 protein expression levels, but not mRNA levels, were significantly higher in metastases than primary-BC. Meta-analysis of gene expression datasets revealed a significant correlation between higher FIP200(RB1CC1)/Atg17 mRNA levels in primary-BC tumors and shorter disease-free survival. CONCLUSIONS: These results support assessments of precision medicine-guided targeting of autophagy in treatment of brain metastases in breast cancer patients.

Accuracy of frozen section in determining meningioma subtype and grade.

Frozen section intraoperative consultation is a well-established means of evaluating brain tumors at the time of surgery. Limitations to the procedure are also well recognized resulting in less than perfect specificity of diagnosis. This study retrospectively reviewed 424 consecutive meningioma cases (N = 310 females; mean age 57.3 years) to examine concordance between frozen section evaluation of meningioma subtype and grade as compared with the final diagnosis subtype and grade. A discrepancy between frozen section diagnosis and final diagnosis was observed in 114 (26.9%) of cases. Of the WHO grade I subtypes, the most common discrepancy involved transitional meningiomas (N = 31) which were most commonly diagnosed at frozen section as either fibrous (N = 18) or meningothelial (N = 13) meningiomas. None of the grade I tumors were diagnosed as higher grade lesions. Of the higher grade meningiomas (WHO grade II and III) (N = 145) reviewed, concordance between tumor type and grade was seen in only 26.2% of cases; most commonly, 73/98 atypical meningiomas were under-graded as some subtype of WHO grade I meningioma (71/73 cases). In conclusion, discrepancies at frozen section with respect to accurately identifying higher grade meningiomas and higher grade meningioma subtypes are common and are generally due to tumor sampling and heterogeneity.

Pathology resident perspectives about early autopsy experiences.

The performance of autopsies remains an integral part of residency training in Anatomic Pathology. A number of medical schools no longer require an autopsy experience; therefore, a subset of pathology residents has never seen an autopsy performed prior to commencement of residency training. Although much as been written regarding student's perspectives on their medical school anatomy experiences, practically nothing has been written about resident perspectives on the autopsy experience. Surveys were sent to all Pathology resident trainees (n = 27) in a training program exploring resident perspectives on their early autopsy experiences. Of the 13 residents who completed the survey, ten indicated a discomfort level of 3 or 4 (Likert scale of 1-5 with 1 = no discomfort and 5 = very uncomfortable) associated with their first autopsy; the most commonly cited reasons included discomfort with odors/body fluids (n = 6), fear of making a mistake (n = 5), and uncertainty about what to do (n = 4). Six residents felt it would be worthwhile to engage in a discussion around the first autopsy experience to help process it. In summary, a subset of residents experience discomfort around their first autopsy experience. Sensitivity to and acknowledgement of this discomfort and an opportunity to vet feelings and concerns should be considered as part of Pathology residency education.

Longitudinal experience with WHO Grade III (anaplastic) meningiomas at a single institution.

To retrospectively analyze and assess the outcomes and prognostic factors in patients with anaplastic meningioma (AM) (WHO Grade III). Clinical data and outcome [overall (OS) and progression-free (PFS) survival] from 18 patients with Grade III meningioma (AM, based on World Health Organization 2016 definition) initially treated between March 2000 and June 2015 were analyzed. Eleven patients (61%) were male, median age at diagnosis was 63 (range 48-86), and 55% (10/18 patients) had good performance status (KPS ≥ 80). Eight patients (45%) had lower grade disease (Grade I-n = 2; Grade II-n = 6) prior to being upgraded to AM. Ten patients had fractionated radiation after primary surgery, eight patients had salvage fractionated RT, stereotactic radiosurgery (SRS) boost along with primary RT in 1 patient, and salvage SRS to 18 separate areas in 14 patients. Salvage chemotherapy was mainly considered in third or fourth recurrences. 13 (72%) patients recurred and 10 (56%) have died. Median PFS was 14.5 months (95% CI 6.9-22.2). The 5-year survival rate was 40 ± 15% and median OS was 55.8 months (95% CI 27.7-80.3). Of all factors examined, only Karnofsky performance status (KPS) affected outcome (PFS p = 0.0003; OS p = 0.0003). With median OS of 55 months (4.6 years) our results are consistent with existing reports of the poor outcomes for AM patients. From the available data, surgical resection followed by RT and salvage radiosurgery and/or chemotherapy can lead to extended survival; however the benefit may decrease with successive treatments.

Correlation of higher levels of soluble TNF-R1 with a shorter survival, independent of age, in recurrent glioblastoma.

The circulating levels of soluble tumor necrosis factor receptor-1 (sTNF-R1) and sTNF-R2 are altered in numerous diseases, including several types of cancer. Correlations with the risk of progression in some cancers, as well as systemic manifestations of the disease and therapeutic side-effects, have been described. However, there is very little information on the levels of these soluble receptors in glioblastoma (GBM). Here, we report on an exploratory retrospective study of the levels of sTNF-Rs in the vascular circulation of patients with GBM. Banked samples were obtained from 112 GBM patients (66 untreated, newly-diagnosed patients and 46 with recurrent disease) from two institutions. The levels of sTNF-R1 in the plasma were significantly lower in patients with newly-diagnosed or recurrent GBM than apparently healthy individuals and correlated with the intensity of expression of TNF-R1 on the tumor-associated endothelial cells (ECs) in the corresponding biopsies. Elevated levels of sTNF-R1 in patients with recurrent, but not newly-diagnosed GBM, were significantly associated with a shorter survival, independent of age (p = 0.02) or steroid medication. In contrast, the levels of circulating sTNF-R2 were significantly higher in recurrent GBM than healthy individuals and there was no significant correlation with expression of TNF-R2 on the tumor-associated ECs or survival time. The results indicate that larger, prospective studies are warranted to determine the predictive value of the levels of sTNF-R1 in patients with recurrent GBM and the factors that regulate the levels of sTNF-Rs in the circulation in GBM patients.

Brain metastasis from gastrointestinal clear cell sarcoma.

Clear cell sarcoma (CCS) of the gastrointestinal tract presents a diagnostic challenge to the pathologist due to its morphological and immunohistochemical similarity to melanoma. It usually metastasizes to regional lymph nodes, liver, and lungs. Herein, we report the first known metastasis of a gastrointestinal CCS to the central nervous system. Cytogenetic testing showed the t(12,22) translocation corresponding to the presence of the EWS/ATF1 hybrid consistent with CCS. The literature that compares melanoma to CCS is reviewed in the context of this rare presentation to differentiate between the two diseases.
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Chronic inflammation in refractory hippocampal sclerosis-related temporal lobe epilepsy.

Emerging evidence suggests chronic inflammation may play a role in hippocampal sclerosis-associated temporal lobe epilepsy. We sought to systematically evaluate for its presence in a group of 315 patients who underwent surgery for medically-refractory epilepsy and who had hippocampal sclerosis. Upon histologic review of hematoxylin and eosin stained tissue sections, 95 (41%) cases demonstrated the presence of lymphocytes within the perivascular region and diffusely within the brain parenchyma. Those cases with chronic inflammation evident on hematoxylin and eosin staining were significantly more likely to experience a post-operative seizure recurrence than those without it (p=0.03). In 9 cases of hippocampi with chronic inflammation observed on hematoxylin and eosin stained sections, there was a mixture of both T (CD3+) and B (CD20+) lymphocytes located around blood vessels and interspersed within the brain parenchyma and a predominance of CD4 positive T cells versus CD8 positive cells. Ten hippocampi, apparently devoid of chronic inflammation upon inspection with hematoxylin and eosin stained sections, were stained with the lymphocyte common antigen CD45. In all 10 cases, scattered lymphoid cells were observed in the brain parenchyma, suggesting some level of chronic inflammation may be present in more cases than casual inspection might suggest. This study was the first to evaluate the incidence of chronic inflammation within a large temporal lobe epilepsy population. The study findings suggest chronic inflammation may be a more common component of hippocampal sclerosis -associated temporal lobe epilepsy than previously believed.

Ultrastructural examination of skin biopsies may assist in diagnosing mitochondrial cytopathy when muscle biopsies yield negative results.

Ultrastructural evaluation of skin biopsies has been utilized for diagnosis of mitochondrial disease. This study investigates how frequently skin biopsies reveal mitochondrial abnormalities, correlates skin and muscle biopsy findings, and describes clinical diagnoses rendered following the evaluation. A retrospective review of surgical pathology reports from 1990 to 2015 identified skin biopsies examined by electron microscopy for suspected metabolic disease. A total of 630 biopsies were included from 615 patients. Of these patients, 178 also underwent a muscle biopsy. Of the 630 skin biopsies, 75 (12%) showed ultrastructural abnormalities and 34 (5%) specifically showed mitochondrial abnormalities including increased size (n=27), reduced or abnormal cristae (n=23), dense matrices (n=20), and increased number (n=8). Additional findings included lysosomal abnormalities (n=13), lipid accumulation (n=2) or glycogen accumulation (n=1). Of the 34 patients with mitochondrial abnormalities on skin biopsy, 20 also had muscle biopsies performed and nine showed abnormalities suggestive of a mitochondrial disorder including absent cytochrome oxidase staining (n=2), increased subsarcolemmal NADH, SDH, or cytochrome oxidase staining (n=1), or ultrastructural findings including large mitochondrial size (n=5), abnormal mitochondrial structure (n=5), and increased mitochondrial number (n=4). The most common presenting symptoms were intellectual disability (n=13), seizures (n=12), encephalopathy (n=9), and gastrointestinal disturbances (n=9). At last known follow-up, 12 patients had a definitive diagnosis of a mitochondrial disorder. One patient each had Complex I deficiency, Complex III deficiency, Charcot-Marie-Tooth disease, pyruvate dehydrogenase deficiency, and Phelan-McDermid syndrome. Our results suggest that skin biopsy sometimes yields diagnostic clues suggestive of a mitochondrial cytopathy in cases with a negative muscle biopsy.

Voxel-based morphometric magnetic resonance imaging (MRI) postprocessing in MRI-negative epilepsies.

OBJECTIVE: In the presurgical workup of magnetic resonance imaging (MRI)-negative (MRI(-) or "nonlesional") pharmacoresistant focal epilepsy (PFE) patients, discovering a previously undetected lesion can drastically change the evaluation and likely improve surgical outcome. Our study utilizes a voxel-based MRI postprocessing technique, implemented in a morphometric analysis program (MAP), to facilitate detection of subtle abnormalities in a consecutive cohort of MRI(-) surgical candidates. METHODS: Included in this retrospective study was a consecutive cohort of 150 MRI(-) surgical patients. MAP was performed on T1-weighted MRI, with comparison to a scanner-specific normal database. Review and analysis of MAP were performed blinded to patients' clinical information. The pertinence of MAP(+) areas was confirmed by surgical outcome and pathology. RESULTS: MAP showed a 43% positive rate, sensitivity of 0.9, and specificity of 0.67. Overall, patients with the MAP(+) region completely resected had the best seizure outcomes, followed by the MAP(-) patients, and patients who had no/partial resection of the MAP(+) region had the worst outcome (p < 0.001). Subgroup analysis revealed that visually identified subtle findings are more likely correct if also MAP(+) . False-positive rate in 52 normal controls was 2%. Surgical pathology of the resected MAP(+) areas contained mainly non-balloon-cell focal cortical dysplasia (FCD). Multiple MAP(+) regions were present in 7% of patients. INTERPRETATION: MAP can be a practical and valuable tool to: (1) guide the search for subtle MRI abnormalities and (2) confirm visually identified questionable abnormalities in patients with PFE due to suspected FCD. A MAP(+) region, when concordant with the patient's electroclinical presentation, should provide a legitimate target for surgical exploration.

Hyaline protoplasmic astrocytopathy with associated focal cortical dysplasia and hippocampal sclerosis.

Hyaline protoplasmic astrocytopathy is a rare histopathologic finding in which there is an accumulation of filamin A within protoplasmic astrocytes. The condition has been reported in association with Aicardi syndrome and in patients with epilepsy. This case reports findings of hyaline protoplasmic astrocytopathy in a 4-year-old female who presented with febrile-onset, medically-intractable epilepsy. She underwent resection of the left lateral temporal lobe, hippocampus, and amygdala. In addition to characteristic eosinophilic, astrocytic cytoplasmic inclusions, the lateral temporal lobe showed changes consistent with ILAE (International League Against Epilepsy) type Ic focal cortical dysplasia/Palmini et al. [12] type IA focal cortical dysplasia. The hippocampal formation was marked by loss of neurons in the CA1 region accompanied by gliosis and a relative sparing of neurons in the CA4 region, consistent with ILAE type 2 hippocampal sclerosis or CA1 sclerosis. The literature on hyaline protoplasmic astrocytopathy and coexistent pathologies in the clinical setting of chronic epilepsy is reviewed.