A case of intravascular lymphoma presenting with a lesion in the splenium of the corpus callosum.

Intravascular lymphoma (IVL) is difficult to diagnose because its clinical presentation and laboratory and imaging findings are nonspecific. Herein, we report a case of IVL presenting as a lesion in the splenium of the corpus callosum. A 52-year-old man attended the emergency department with a 2-week history of progressively worsening abnormal behavior and gait disturbance. Magnetic resonance imaging on admission revealed an oval lesion in the splenium of the corpus callosum. The follow-up magnetic resonance imaging performed 2 months after disease onset revealed multiple high-signal areas in the bilateral cerebral white matter on T2-weighted images and diffusion-weighted images. The blood test results showed an elevated level of lactate dehydrogenase and serum-soluble interleukin-2 receptor. These findings were compatible with the diagnosis of IVL. IVL is often difficult to diagnose due to a wide variety of clinical presentations and imaging findings.

Development of Polyneuropathy, Organomegaly, Endocrinopathy, M Protein, and Skin Changes Syndrome after Conversion from Plasmacytoma of Bone to Multiple Myeloma.

A 36-year-old man developed polyneuropathy, organomegaly, endocrinopathy, M protein, and skin changes (POEMS) syndrome after conversion from solitary plasmacytoma of bone to multiple myeloma. Twenty-four days following the neurological onset, he lost his independent walking ability. The level of serum vascular endothelial growth factor (VEGF) at diagnosis was 5,250 pg/mL. Three months after initiating treatment, he regained his independent walking ability in line with a reduction in the elevated serum VEGF level. Due to their genomic instability gained during conversion, myeloma cells may overproduce humoral factors and cytokines, possibly contributing to the development of neuropathy as well as the production of VEGF.

Spinal Cord Infarction in a Patient with Immune Thrombocytopenic Purpura.

Immune thrombocytopenic purpura (ITP) can increase the risk of not only hemorrhagic incidents but also thrombotic events. Although several patients with ITP who developed cerebral infarction have been reported, concurrence of spinal cord infarction and ITP has not been reported. We report the case of a female patient who developed spinal cord infarction during the exacerbation of her ITP. This case suggests a possible association between spinal cord infarction and ITP, which can cause paradoxical thrombosis.

Anti-LGI1 Encephalitis Developing Immunoglobulin Responsive Orthostatic Hypotension after Remission.

Anti-leucine-rich glioma-inactivated 1 (LGI1) antibody is associated with limbic encephalitis. We herein report a patient with anti-LGI1 encephalitis who developed severe orthostatic hypotension (OH) responsive to immunoglobulin therapy five years after developing symptoms of encephalitis. A 71-year-old man presented with amnesia caused by limbic encephalitis. The symptoms of encephalitis improved partially without any immunotherapy. Five years later, he developed severe OH, and anti-LGI1 antibody was positive. The catecholamine dynamics indicated that the central autonomic nervous system was the lesion of his OH. Intravenous immunoglobulin therapy improved the OH. This case suggests that anti-LGI1 antibody can be associated with severe OH.

Clinical Characteristics of Epidemic Myalgia Associated with Human Parechovirus Type 3 during the Summer of 2019.

Objective Epidemic myalgia associated with human parechovirus type 3 (EM-HPeV3) is characterized by severe muscle pain and weakness on the limbs and trunk with a fever. No outbreak of EM-HPeV3 has been reported since 2016, and its clinical characteristics have not been sufficiently clarified. We herein report a series of EM-HPeV3 cases during the summer of 2019 and clarify the clinical characteristics of EM-HPeV3. Methods The diagnosis of EM-HPeV3 was established when the patients met both of the following criteria: (1) Patients developed severe muscle pain and weakness with a fever within a week, and those symptoms resolved within a month; and (2) HPeV3 was detected in either a throat swab or fecal specimen of the patient by polymerase chain reaction. We reviewed the medical records of these patients retrospectively. Results Seven patients met the criteria (6 men and 1 woman, age 34 to 47 years old). Myalgia was observed on the thigh, lower legs, upper arms, and forearms in seven, five, two, and five patients, respectively. Four patients showed distal dominant weakness on the arms, while none of the patients showed proximal dominant weakness on the arms. Of the six patients examined, five showed reduced tendon reflexes on all four limbs. One patient showed slight myogenic change and increased insertion activities on needle electromyography. Conclusion We observed seven cases of EM-HPeV3 during the summer of 2019. Reduced tendon reflexes and distal dominancy of muscle pain and weakness on the arms are considered its distinct clinical features.

Embryonal tumor with abundant neuropil and true rosettes with only one structure suggestive of an ependymoblastic rosette.

Embryonal tumor with abundant neuropil and true rosettes (ETANTR) is a very aggressive embryonal central nervous system (CNS) tumor, histologically featuring ependymoblastic rosettes and neuronal differentiation in a neuropil-like background. 19q13.42 amplification was identified in ETANTR and epndymoblastoma, suggesting that these tumors constitute a single entity, called embryonal tumor with multilayered rosettes (ETMR). Here, we report a case involving a 2-year-old boy with a pontine embryonal tumor composed of clusters of poorly differentiated neuroepithelial cells, and smaller neuroblastic/neurocytic cells in a fibrillary and paucicellular neuropil-like matrix, where clear ependymoblastic rosettes were not detected but only one structure suggestive of an ependymoblastic multilayered rosette was found. Fluorescence in situ hybridazation analysis revealed 19q13.42 amplification, supporting the diagnosis of ETANTR. This report indicates that rare ependymoblasic rosettes found in embryonal tumors, which are otherwise CNS primitive neuroectodermal tumors or medulloblastomas, are significant for considering the examination of 19q13.42 amplification to confirm the diagnosis of ETMR.