RESUMO
Studies on ligamentum flavum hematoma (LFH) have been gradually increasing; however, no study has reported an LFH spreading to the intraspinal and extraspinal spaces. The purpose of this report is to discuss this rare condition and report that extraspinal hematoma can be formed by LFH. The authors present the case of a 78-year-old man presented with right L5 radiculopathy caused by a space-occupying lesion with intraspinal and extraspinal expansions at the L4-L5 vertebral levels demonstrated on MRI. We tentatively diagnosed these lesions as intraspinal and extraspinal hematomas originating from the ligamentum flavum based on the chronological changes seen on MRI and computed tomography-based needle biopsy. After the extirpation of these lesions, the symptoms were relieved. Three months later, the patient could walk without a cane. From the intraoperative findings and pathological examination, we concluded that the extraspinal hematoma in paravertebral muscle was caused by an LFH of unknown etiology. This case report describes the difficulty in diagnosing LFH accompanied by an extraspinal hematoma with wide-spreading expansion and highlights the usefulness of repetitive MRI over time in capturing chronological changes of the hematoma. As far as we know, this is the first study on an LFH accompanied by an extraspinal hematoma in the multifidus.
RESUMO
BACKGROUND: MicroRNA (miRNA) is an emerging subclass of small non-coding RNAs that regulates gene expression and has a pivotal role for many physiological processes including cancer development. Recent reports revealed the role of miRNAs as ideal biomarkers and therapeutic targets due to their tissue- or disease-specific nature. Head and neck cancer (HNC) is a major cause of cancer-related mortality and morbidity, and laryngeal cancer has the highest incidence in it. However, the molecular mechanisms involved in laryngeal cancer development remain to be known and highly sensitive biomarkers and novel promising therapy is necessary. METHODOLOGY/PRINCIPAL FINDINGS: To explore laryngeal cancer-specific miRNAs, RNA from 5 laryngeal surgical specimens including cancer and non-cancer tissues were hybridized to microarray carrying 723 human miRNAs. The resultant differentially expressed miRNAs were further tested by using quantitative real time PCR (qRT-PCR) on 43 laryngeal tissue samples including cancers, noncancerous counterparts, benign diseases and precancerous dysplasias. Significant expressional differences between matched pairs were reproduced in miR-133b, miR-455-5p, and miR-196a, among which miR-196a being the most promising cancer biomarker as validated by qRT-PCR analyses on additional 84 tissue samples. Deep sequencing analysis revealed both quantitative and qualitative deviation of miR-196a isomiR expression in laryngeal cancer. In situ hybridization confirmed laryngeal cancer-specific expression of miR-196a in both cancer and cancer stroma cells. Finally, inhibition of miR-196a counteracted cancer cell proliferation in both laryngeal cancer-derived cells and mouse xenograft model. CONCLUSIONS/SIGNIFICANCE: Our study provided the possibilities that miR-196a might be very useful in diagnosing and treating laryngeal cancer.