An autopsy case of intravascular large B-cell lymphoma showing a rapid transition to embolic strokes with occlusion of the major cerebral arteries.

Intravascular large B-cell lymphoma can induce central nervous system manifestations, including strokes, due to small-vessel occlusion caused by lymphoma cells. However, involvement in large-sized vessels is rare. Here, we present an unusual autopsy case of an 88-year-old man showing a rapid transition from multiple strokes due to small vessel occlusion, typical of intravascular lymphoma, to progressive embolic strokes caused by the occlusion of major cerebral arteries. Magnetic resonance angiography demonstrated the major cerebral arteries associated with those multiple progressive strokes, including the right posterior cerebral artery, left anterior cerebral artery, and right middle cerebral artery, but the detectability was poor. A random skin biopsy at the abdomen confirmed the diagnosis of intravascular large B-cell lymphoma. The patient died 106 days after hospitalization despite intensive treatment. An autopsy revealed broad liquefactive necrosis in the area governed by the major cerebral arteries and multiple small infarctions caused by intravascular lymphoma cells in the small-sized vessels. In addition, the major cerebral arteries showed multiple thromboembolism with partial organization and clusters of intravascular lymphoma cells. Notably, those cells were shown aggregated and attached along the vascular wall of the basilar artery, which might have caused focal hypercoagulation in the near vessels. This aggregation might have disseminated widely in the other major cerebral arteries. Moreover, the cluster of intravascular lymphoma cells in the basilar artery was positive for tumor necrosis factor α, and similar histopathology findings were observed in the splenic veins. However, the pathogenesis of this rare phenomenon involving these cells remains unknown. From a clinical perspective, we should consider the possibility that intravascular lymphoma cells may provoke similar progressive embolic strokes.

Characteristic differences in the abundance of tumor-infiltrating lymphocytes and intratumoral developing T cells in thymoma, with special reference to PD-1 expression.

PURPOSE: Though programmed cell death-1 (PD-1) inhibitors mainly target tumor-infiltrating lymphocytes (TILs) expressing PD-1, developing T cells in thymus also express PD-1 in their process of maturation. To predict the therapeutic effect of PD-1 inhibitors for thymoma, it is necessary to clarify the proportions of TILs and intratumoral developing T cells. METHODS: The expressions of CD4, CD8, and PD-1 on T cells were analyzed by flow cytometry in 31 thymomas. The amount of T cell receptor excision circles (TRECs), which can be detected in newly formed naïve T cells in the thymus, was evaluated using sorted lymphocytes from thymomas by quantitative PCR. The expressions of granzyme B (GZMB) and lymphocyte activation gene-3 (LAG-3) in PD-1 + CD8 T cells were analyzed by image cytometry using multiplex immunohistochemistry. RESULTS: The PD-1 + rate in both CD4 and CD8 T cells was significantly higher in type AB/B1/B2 than in type A/B3 thymomas. The amounts of TRECs in CD4 and CD8 T cells were significantly higher in type AB/B1/B2 than in type A/B3 thymomas and comparable to normal thymus. PD-1 expression at each stage of T cell development of type AB/B1/B2 thymomas was comparable to that of normal thymus. Both the percentages and cell densities of PD-1 + CD8 T cells expressing GZMB or LAG-3, which are known to contain tumor-reactive T cells, were significantly lower in type AB/B1/B2 thymomas. CONCLUSION: Most PD-1 + T cells in type AB/B1/B2 thymomas are intratumoral developing T cells and are not TILs.

Loss of abnormal spindle-like, microcephaly-associated (Aspm) disrupts female folliculogenesis in mice during maturation and aging.

The abnormal spindle-like, microcephaly-associated (ASPM) gene is a causative gene of autosomal recessive primary microcephaly (MCPH) 5 in humans, which is characterized by a reduction in brain volume. It was previously reported that truncated Aspm proteins in transgenic mice caused major defects in the germline, a severe reduction in ovary weight and the number of follicles accompanied by reduced fertility. However; it remains unknown whether a loss of Aspm induces abnormal ovarian function, resulting in female infertility. In order to assess the ovary function, we examined vaginal smear cytology from the age of 7 weeks to 100 weeks in CAG-mediated Cre-loxP conditional Aspm-/- knockout mice and control female mice. In addition, we evaluated the ovarian size, fibrosis ratio and the number of follicles (primordial, primary, secondary, antral and atretic follicles) in mice from 15 weeks to 100 weeks old by image analyses. Mann-Whitney U-test was used for statistical analysis. The size of the ovary was significantly reduced in Aspm knockout mice at 15-20 weeks, 40-50 weeks and 70-80 weeks old compared with the control mice. Furthermore, at all stages, we found a severe decrease in the number of developing follicles at 10-15 weeks, 40-50 weeks and 70-80 weeks old, accompanied by disrupted cyclic changes of vaginal cytology and an aberrant upregulation of Foxo3, Kitl, and Lhcgr in Aspm knockout female. These results suggested that Aspm might play an important role in the folliculogenesis and estrous cyclicity of the postnatal ovary during maturation and aging.

An autopsy case of COVID-19 with a sudden death: Clinico-pathological comparison.

Autopsy was performed on a COVID-19 patient, who suddenly died despite the extensive anti-viral and anti-inflammatory therapies. Although moderate subpleural fibrosis was seen, pathology of DAD, a well-known cause for pulmonary failure, was minimum. Instead, severe hemorrhage was observed. Therapeutic effects were indicated; however, why severe hemorrhage occurred was unclear.

An autopsy case of corticobasal syndrome due to asymmetric degeneration of the motor cortex and substantia nigra with TDP-43 proteinopathy, associated with Alzheimer's disease pathology.

We herein report a case of corticobasal syndrome (CBS) due to asymmetric degeneration of the motor cortex and substantia nigra with transactivation response DNA-binding protein of 43 kDa (TDP-43) proteinopathy, associated with Alzheimer's disease (AD) pathology. An 85-year-old man initially noticed that he had difficulty in walking and had trouble in moving his right hand and lower limb one year later. His gait disturbance was aggravated, and at the age of 87 years, his neurological examination revealed parkinsonism and positive frontal lobe signs. Brain magnetic resonance imaging (MRI) revealed atrophy of the left frontotemporal lobe and cerebral peduncle, and cerebral blood flow scintigraphy revealed hypoperfusion of the left frontotemporal lobe, leading to a possible diagnosis of CBS. At the age of 89 years, he was bedridden, and rarely spoke. He died of aspiration pneumonia five years after the onset of initial symptoms. At the autopsy, the brain weighed 1280 g and showed left-sided hemiatrophy of the cerebrum and cerebral peduncle. Neuropathological examination revealed AD pathology (Braak AT8 stage V, Braak stage C, CERAD B, Thal classification 5). Phosphorylated TDP-43 (p-TDP-43) immunohistochemistry revealed widespread deposits of dystrophic neurites (DNs), glial cytoplasmic inclusions (GCIs), and neuronal cytoplasmic inclusions (NCIs), which were most remarkable in layers II/III of the motor cortex and predominant on the left hemisphere of the frontal cortex, these neuropathology being consistent with frontotemporal lobar degeneration with TDP-43 (FTLD-TDP) type A. Interestingly, neuronal loss in the substantia nigra was more severe on the left than the right side, with a few phosphorylated tau (p-tau) and p-TDP-43 deposits. It is highly likely that asymmetric TDP-43 pathology rather than symmetric tau pathology contributed to the laterality of degeneration of the cerebral cortex, substantia nigra, and pyramidal tract, which led us to suggest that TDP-43 proteinopathy might be a primary cause.

Maldevelopment of intrapulmonary bronchial cartilage in congenital diaphragmatic hernia.

BACKGROUND: Pulmonary hypoplasia is an important cause of morbidity and mortality in infants with congenital diaphragmatic hernia (CDH). This study aimed to verify our hypothesis that the abnormal development of bronchial cartilage as well as alveolar immaturity, might play a central role in hypoplasia of the lung in human CDH. METHOD: We retrospectively analyzed autopsied lungs from 10 CDH cases and compared with nine age-matched controls to assess the bronchial cartilage and alveolar maturity using morphological techniques. RESULT: Ki-67 and thyroid transcription factor-1 (TTF-1) expression in the alveoli significantly increased in bilateral lungs with CDH. The shortest distance from the bronchial cartilage to the pleura was significantly shorter in ipsilateral (left) lungs with CDH, showing a positive correlation with the radial alveolar count (RAC). Regarding the small bronchial cartilages less than 20 000 µm2 , the average cartilage area significantly decreased in left lungs with CDH, and tended to decrease in right lungs with CDH. In addition, cartilage around the bronchi less than 200 µm in diameter tended to be smaller in left lungs with CDH. In contrast, regarding the cartilage around the bronchi 200 to 400 µm in diameter, the ratio of the total cartilage area relative to the bronchial diameter tended to be higher in left lungs with CDH, although there was a large variation. CONCLUSIONS: These opposite directional cartilage abnormalities around the distal and more proximal bronchi support our hypothesis that abnormal development of bronchial cartilage might play an important role in the hypoplastic lung in CDH.

High-grade transformation/dedifferentiation of an adenoid cystic carcinoma of the minor salivary gland to myoepithelial carcinoma.

High-grade transformation (HGT)/dedifferentiation is an unusual phenomenon in salivary gland carcinomas. Here we report a case of adenoid cystic carcinoma (ACC) with HGT/dedifferentiation to myoepithelial carcinoma, occurring in the epipharynx of a 42-year-old woman. The surgically resected tumor was a pedunculated mass, 31 × 25 mm in size, which had two histologically distinct carcinomatous areas, including a high-grade sarcomatoid area composed of pleomorphic spindle cells and an area consisting of low-grade typical ACC. These two components gradually changed from the low-grade to the high-grade component. MIB-1 index in the low-grade and high-grade component was 15% and 50%, respectively. An immunohistochemical profile of the high-grade component showed immunoreactivity for α-SMA, p63, calponin and focal S100, as well as for several cytokeratin markers, which were compatible with the features of myoepithelial carcinoma. In contrast, the immunohistochemical profile of the low-grade component coincided with that of typical ACC. This HGT/dedifferentiation to myoepithelial carcinoma is extremely rare. The pathogenesis of HGT/dedifferentiation in salivary gland carcinomas still remains largely unknown, regardless of the presence or absence of myoepithelial differentiation. Further studies are required due to the more aggressive biological behavior and poorer prognosis associated with ACC with HGT/dedifferentiation, compared with conventional ACC.

Longitudinal Diffusion Tensor Imaging Revealed Nerve Fiber Alterations in Aspm Mutated Microcephaly Model Mice.

Autosomal recessive primary microcephaly-5 (MCPH5) is characterized by congenital microcephaly and is caused by the mutation in the abnormal spindle-like, microcephaly-associated (ASPM) gene. This study aimed to demonstrate a correlation between radiological and pathological analyses in evaluating postnatal brain development using MCPH5-model mice, ASPM ortholog (Aspm) knockout (KO) mice. In vivo MRI was performed at two time points (postnatal 3 weeks; P3W and P10W) and complementary histopathological analyses of brains were done at P5W and P13W. In the MRI analysis, Aspm KO mice showed significantly decreased brain sizes (average 8.6% difference) with larger ventricles (average 136.4% difference) at both time points. Voxel-based statistics showed that the fractional anisotropy (FA) values were significantly lower in Aspm KO mice in both the cortex and white matter at both time points. Developmental changes in the FA values were less remarkable in the Aspm KO mice, compared with the controls. Histometric analyses revealed that the ratios of the horizontal to the vertical neurites were significantly higher in cortical layers IV, V and VI, with a remarkable increase according to maturation at P13W in the control mice (average 12.7% difference between control and KO), whereas the ratio in layer VI decreased at P13W in the KO mice. The myelin basic protein positive ratio in the white matter significantly decreased in Aspm KO mice at P5W. These results suggest that temporal FA changes are closely correlated with pathological findings such as abnormal neurite outgrowth and differentiation, which may be applicable for analyzing diseased human brain development.

Knowledge Obtained from an Elderly Case of Japanese Encephalitis.

The nationwide introduction of a Japanese encephalitis (JE) vaccine has contributed to a reduction in the annual infection rate of JE in Japan. However, the current neutralizing antibody prevalence ratio in Japan is approximately 20% in children 3-4 years of age and in people in their forties and fifties. We herein report a man with JE who was definitively diagnosed by multi-virus real-time polymerase chain reaction employing biopsied brain tissue and serological examinations. JE should be kept in mind when a patient has severe encephalitis of unknown etiology. In order to protect the susceptible population from JE, vaccination is recommended, especially for children and middle-aged people.

Quadruple Cancers of Non-producing Multiple Myeloma, Cholangiocellular Carcinoma, and Two Different Thyroid Cancers.

We report the case of a 72-year-old man who presented with non-producing multiple myeloma (MM) with three additional concomitant solid tumors that were identified by postmortem autopsy. The disease was refractory to anti-MM therapy including bortezomib and lenalidomide, and he finally died of bacterial pneumonia with diffuse alveolar damage 8 months after the diagnosis. An autopsy revealed that he was also affected by three other solid cancers, cholangiocellular carcinoma, medullary thyroid cancer and papillary thyroid cancer that were clinically asymptomatic and remained undiagnosed before death. A review of the literature suggests that primary quadruple cancers including MM are extremely rare.

Oncogenic Lmo3 cooperates with Hen2 to induce hydrocephalus in mice.

We previously reported that LMO3 and HEN2 act as oncogenes in neuroblastoma development through up-regulating MASH1 transcription by interfering with HES1. To confirm these results in vivo, we generated transgenic mice of these genes. Lmo3 or Hen2 was expressed under the control of Wnt1 promoter, which is expressed in the central nervous system and neural crest of the sympathoadrenal lineage from which neuroblastoma develops. Heterozygous Lmo3 and Hen2 transgenic mice (Tg (Lmo3) and Tg (Hen2)) developed hydrocephalus at higher frequency than for the wild type mice, and all heterozygous double-transgenic mice (Tg (Lmo3; Hen2)) developed hydrocephalus. Therefore, Lmo3 and Hen2 may be involved in and have synergistic effects on hydrocephalus development. Although aqueduct stenosis occurred in all genotypes, it was mild in Tg (Lmo3; Hen2) mice. Furthermore, hydrocephalus was detected at E18.5 in Tg (Lmo3; Hen2). These results suggest that the causes of hydrocephalus are not only aqueduct stenosis but also disorder of neocortical development. A similar phenotype was reported in Robo1/2(-/-) mice, in which Hes1 expression level was decreased in ventricular zone progenitors. Thus, it is suggested that the expression levels of Lmo3 and/or Hen2 could determine the fate of stem cells by inhibiting Hes1 function during nervous system development and might be a trigger of aberrant neurogenesis in vivo.

An autopsy case of Balamuthia mandrillaris amoebic encephalitis, a rare emerging infectious disease, with a brief review of the cases reported in Japan.

Balamuthia mandrillaris is an amoeba found in fresh water and soil that causes granulomatous amoebic encephalitis. We report herein an autopsy case of B. mandrillaris amoebic encephalitis, which was definitely diagnosed by PCR. An 81-year-old man, who had Sjögren's syndrome, manifested drowsiness 2 months before his death with progressive deterioration. Neuroimaging demonstrated foci of T2- and fluid-attenuated inversion recovery high and T1 low-intensity with irregular post-contrast ring enhancement in the cerebral hemisphere, thalamus and midbrain. Pathologically, multiple hemorrhagic and necrotic lesions were found in the cerebrum, thalamus, midbrain, pons, medulla and cerebellum, which were characterized by liquefactive necrosis, marked edema, hemorrhage and necrotizing vasculitis associated with the perivascular accumulation of amoebic trophozoites, a few cysts, and the infiltration of numerous neutrophils and microglia/macrophages. The trophozoites were ovoid or round, 10-60 µm in diameter, and they showed foamy cytoplasm and a round nucleus with small karyosome in the center. The PCR and immunohistochemistry from paraffin-embedded brain specimens revealed angioinvasive encephalitis due to B. mandrillaris. Human cases of B. mandrillaris brain infection are rare in Japan, with only a few brief reports in the literature.

Bisphenol A exposure disrupts the development of the locus coeruleus-noradrenergic system in mice.

It has been reported that bisphenol A (BPA), a widespread xenoestrogen employed in the production of polycarbonate plastics, affects brain development in both humans and rodents. In the present study employing mice, we examined the effects of exposure to BPA (500 µg/kg/day) during fetal and lactational periods on the development of the locus coeruleus (LC) at the age of embryonic day 18 (E18), postnatal 3 weeks (P3W), P8W and P16W. The number of tyrosine hydroxylase-immunoreactive cells (TH-IR cells) in females exposed to BPA was decreased, compared with the control females at P3W. At P8W, the number of TH-IR cells in females exposed to BPA was significantly decreased, compared with the control females, whereas the number of TH-IR cells in males exposed to BPA was significantly increased, compared with the control males, which resulted in reversed transient sexual differences in the numbers of TH-IR cells observed in the controls at P8W. However, no significant changes were demonstrated at E18 or P16W. Next, we examined the density of the fibers containing norepinephrine transporter (NET) in the anterior cingulate cortex (ACC) and prefrontal cortex, at P3W, P8W and P16W, because NET would be beneficial in identifying the targets of the LC noradrenergic neurons. There were no significant differences shown in the density of the NET-positive fibers, between the control and the groups exposed to BPA. These results suggested that BPA might disrupt the development of physiological sexual differences in the LC-noradrenergic system in mice, although further studies are necessary to clarify the underlying mechanisms.

The shortest isoform of dystrophin (Dp40) interacts with a group of presynaptic proteins to form a presumptive novel complex in the mouse brain.

Duchenne muscular dystrophy (DMD) causes cognitive impairment in one third of the patients, although the underlying mechanisms remain to be elucidated. Recent studies showed that mutations in the distal part of the dystrophin gene correlate well with the cognitive impairment in DMD patients, which is attributed to Dp71. The study on the expression of the shortest isoform, Dp40, has not been possible due to the lack of an isoform specific antibody. Dp40 has the same promoter as that found in Dp71 and lacks the normal C-terminal end of Dp427. In the present study, we have raised polyclonal antibody against the N-terminal sequence common to short isoforms of dystrophin, including Dp40, and investigated the expression pattern of Dp40 in the mouse brain. Affinity chromatography with this antibody and the consecutive LC-MS/MS analysis on the interacting proteins revealed that Dp40 was abundantly expressed in synaptic vesicles and interacted with a group of presynaptic proteins, including syntaxin1A and SNAP25, which are involved in exocytosis of synaptic vesicles in neurons. We thus suggest that Dp40 may form a novel protein complex and play a crucial role in presynaptic function. Further studies on these aspects of Dp40 function might provide more insight into the molecular mechanisms of cognitive impairment found in patients with DMD.

Left ventricular free wall rupture associated with a combination of acute myocardial infarction and stress-provoked cardiomyopathy: An autopsy case.

A 74-year-old female was admitted to our hospital due to prolonged chest pain that had lasted about 2 h. An electrocardiogram revealed ST-elevation in leads I, aVL, and V3-6, with an increase in myocardial necrosis markers. Emergency coronary angiography was performed, and left ventriculography showed the typical features of apical ballooning, and so a diagnosis of Takotsubo cardiomyopathy (TC) was made. On the 10th day after admission, the patient suddenly went into cardiopulmonary arrest because of a blow-out type left ventricular (LV) free wall rupture. Despite extensive cardiopulmonary resuscitation, the patient died. The autopsy revealed hemopericardium and a perforating wound located in the anterior wall of the LV. It was revealed that the diagonal branch of the coronary artery was occluded, and so a diagnosis of TC coexisting with acute myocardial infarction (AMI) was made. No previous case of TC accompanied by AMI has been reported. We present its clinical course during hospitalization and the result of a histopathologic examination.

Effects of pre- and neonatal exposure to bisphenol A on murine brain development.

Bisphenol A (BPA), known as an environmental endocrine disrupter, is widely used in industry and dentistry. We investigated the effects of fetal and neonatal exposure to bisphenol A (BPA) on the brain development of mice. The density of tyrosine hydroxylase (TH)-immunoreactive (IR) neurons in substantia nigra was significantly decreased in BPA-exposed female mice (3 microg/g powder food), but not in the male mice, as compared with that of the control mice. The densities of calbindin D-28 K-, calretinin- and parvalbumin-IR neurons in the cerebral cortex were not different between BPA-exposed and the control mice. The present study indicates that chronic exposure of BPA during prenatal and neonatal periods causes a decrease of TH-positive neurons in substantia nigra only in female mice brain.

Spatiotemporal patterns of expression of IGSF4 in developing mouse nervous system.

IGSF4 is a novel immunoglobulin (Ig)-like intercellular adhesion molecule. Since IGSF4 has been characterized by several independent research groups, this molecule is called by three names, TSLC1, SgIGSF and SynCAM. In the experiments to study global changes of gene expression in fetal murine brains after prenatal exposure to low-doses of X-rays, we have found IGSF4 as one of down-regulated genes after X-irradiation. In order to elucidate the expression of spatiotemporal expression of IGSF4 in the developing brain, we have produced polyclonal antibody against IGSF4 and studied the expression of IGSF4 with immunohistochemistry and Western blot analysis. At embryonic day (E) 12.5, IGSF4-immunoreactivity (IR) was observed diffusely in the telencephalic wall, whereas it became rather confined to the subplate, the cortical plate and the subventricular zone as the development proceeded. Noteworthy was a distinct radial pattern found in the cortical plate of E16.5. IGSF4-IR gradually decreased after birth and disappeared in adulthood. In the cerebellum, IGSF4 was expressed in the molecular layer at postnatal day (P) 0 through P14. By Western blot analysis, IGSF4 remained at low levels throughout embryonic stage, whereas it increased after birth. These spatiotemporal patterns of the expression suggest that IGSF4 plays crucial roles in the development of both telencephalon and cerebellum.