Multifocal primary amelanotic meningeal melanomas mimicking lymphoma: a case report and literature review.

Primary meningeal melanoma is a rare type of melanocytic cancer originating from the melanocytes of the leptomeninges. It commonly presents as a solitary mass, and multifocal amelanotic lesions were scarcely reported. Diagnosis of multifocal melanoma is particularly challenging, clinically and diagnostically, especially in the absence of cutaneous nevi and melanin pigment. Surgical biopsy result is the gold standard. In this case study, we present an uncommon case of multifocal primary amelanotic meningeal melanomas mimicking lymphomas in the skull base and near the Sylvian fissure, which serves to provide reference value to the clinical diagnosis. Physicians should be aware of the existence of this special type in the clinical work.

Spontaneous Spinal Epidural Hematoma Complicated by Pulmonary Embolism During Pregnancy: A Case Report.

Background: Spontaneous spinal epidural hematoma, without discernable underlying conditions, is considered a neurological emergency, and is rare during pregnancy. Case Presentation: We report the case of a 24-year-old patient at 37 weeks of gestation. She had back pain that progressed to paraplegia of both lower limbs within 2 days. Thoracic magnetic resonance imaging revealed a lesion behind the spinal cord at the T5-T6 level, suggestive of spontaneous spinal epidural hematoma. Due to the rapid recovery of muscle strength in her lower limbs after an emergency cesarean section, we used methylprednisolone therapy to reduce spinal edema rather than decompression of the spinal canal. We incidentally found that the patient's left pulmonary artery was occluded. In consideration of spontaneous spinal epidural hematoma as relative contraindication to anticoagulation, and in the absence of pulmonary embolism symptoms, including good partial oxygen pressure, we did not administer anticoagulant therapy. The patient's condition improved rapidly in the following week. Conclusion: Spontaneous spinal epidural hematoma concomitant with pulmonary artery embolism is an extremely rare manifestation during pregnancy. As exemplified by our case, desirable treatment outcomes are possible under such cases.

DNA Methylation: A Target in Neuropathic Pain.

Neuropathic pain (NP), caused by an injury or a disease affecting the somatosensory nervous system of the central and peripheral nervous systems, has become a global health concern. Recent studies have demonstrated that epigenetic mechanisms are among those that underlie NP; thus, elucidating the molecular mechanism of DNA methylation is crucial to discovering new therapeutic methods for NP. In this review, we first briefly discuss DNA methylation, demethylation, and the associated key enzymes, such as methylases and demethylases. We then discuss the relationship between NP and DNA methylation, focusing on DNA methyltransferases including methyl-CpG-binding domain (MBD) family proteins and ten-eleven translocation (TET) enzymes. Based on experimental results of neuralgia in animal models, the mechanism of DNA methylation-related neuralgia is summarized, and useful targets for early drug intervention in NP are discussed.

Inflammation and histone modification in chronic pain.

Increasing evidence suggests that epigenetic mechanisms have great potential in the field of pain. The changes and roles of epigenetics of the spinal cord and dorsal root ganglia in the chronic pain process may provide broad insights for future pain management. Pro-inflammatory cytokines and chemokines released by microglia and astrocytes, as well as blood-derived macrophages, play critical roles in inducing and maintaining chronic pain, while histone modifications may play an important role in inflammatory metabolism. This review provides an overview of neuroinflammation and chronic pain, and we systematically discuss the regulation of neuroinflammation and histone modifications in the context of chronic pain. Specifically, we analyzed the role of epigenetics in alleviating or exacerbating chronic pain by modulating microglia, astrocytes, and the proinflammatory mediators they release. This review aimed to contribute to the discovery of new therapeutic targets for chronic pain.

Epidemiology, Characteristic, and Prognostic Factors of Primary Sporadic Intradural Malignant Peripheral Nerve Sheath Tumor in the Spinal Canal: A Systematic Literature Review.

Purpose: Primary sporadic intradural malignant peripheral nerve sheath tumor (MPNST) in the spinal canal is a type of rare neoplasm with challenging diagnosis and therapy. The overall prognosis of this tumor is markedly different from that of the usual spinal intradural tumors. The purpose of this systematic review is to reduce the misdiagnosis and enhance the prognosis of the disease by reviewing the literature. Methods: PubMed, Medline, and Embase databases were searched for articles in English language published from 1980 to May 2021, yielding 500 potentially relevant articles. The keywords were as follows: "spinal", "malignant peripheral nerve sheath tumor", "neurosarcoma", "malignant schwannoma", and "malignant neurofibroma". Thirteen papers met the eligibility criteria, including 55 cases with spinal intradural primary sporadic MPNSTs, which were confirmed by post-operation pathology. We further analyzed the clinical manifestations, radiological manifestations, pathological features, comprehensive treatment strategies, and prognosis. Results: Fifty-five spinal intradural primary sporadic MPNSTs from 30 (54.5%) male and 25 (45.5%) female patients with an average age at diagnosis of 40 years (range, 3-70 years) were included in the study. The most common clinical manifestations were local or radicular pain and motor disturbance. All tumors had significant enhancement and heterogeneous enhancement was more common. Out of 18 lesions, 14 were diagnosed as high grade and the remaining 4 were diagnosed as low grade. The ki-67 labeling index ranged from 5% to 60%. The median recurrence and survival time were 36 and 72 months, respectively. The log-rank tests indicated that significant predictors of OS were patient age (≤30 vs. >30 years) at the time of diagnosis and the presence of metastatic disease, and similar analyses for RFS demonstrated that the presence of metastatic disease was the only significant predictor (60 vs. 10 months). The multivariate Cox proportional hazards regression analysis revealed that absence of metastasis was an independent factor for predicting a favorable prognosis. Conclusions: Spinal intradural primary sporadic MPNSTs are challenging malignant tumors without a systematic treatment plan. The factors affecting its prognosis are not clear. Even after surgical treatment and adjuvant treatment, the recurrence rate and mortality rate are still high. Clinicians should be alert to the possibility of this disease and achieve early detection and treatment.

Colchicine poisoning complicated by medulla oblongata myelinolysis: a case report.

Medulla oblongata myelinolysis is an extremely rare manifestation of extrapontine myelinolysis (EPM). Herein, we report a case of a 34-year-old man with a history of gout who presented repeated vomiting and diarrhea after ingesting 15 colchicine pills. A hyponatremia diagnosis was given and after an intensive treatment, his serum sodium level increased from 118 to 129 mmol/L within 24 hours. Brain magnetic resonance imaging (MRI) revealed a lesion in the medulla oblongata that appeared as a hypointense area in T1-weighted images and a hyperintense area in T2-weighted images. A diagnosis of medulla oblongata myelinolysis and colchicine poisoning was then given, and methylprednisolone therapy was initiated. Seventeen days later, the patient achieved a good outcome with methylprednisolone therapy. However, his medulla oblongata lesion remained detectable with MRI. Medulla oblongata myelinolysis is an extremely rare manifestation of EPM, and unique for being colchicine-induced. This case shows that colchicine poisoning can lead to hyponatremia, which in turn can induce myelinolysis if not treated correctly. As exemplified by our patient's case, desirable treatment outcomes are possible in such cases, although these outcomes may not be associated with a visible reduction of the brain lesions in MRI scans.