Duration of ischemia/compression and blood flow recovery of the spinal cord are important factors in the recovery of motor function after a spinal cord injury.

Salivary duct carcinoma (SDC) is a high-grade carcinoma with poor prognosis, especially among various salivary carcinomas. In this study, we report a rare case of SDC of the parotid gland originating from an epithelial-myoepithelial carcinoma (EMC). A 71-year-old Japanese man presented with swelling of the right parotid region and a right facial nerve paralysis for 10 months. He underwent extended total parotidectomy and chemoradiotherapy after the surgery. Histologically, a major part of the tumor was an androgen receptor (AR)-positive, human epidermal growth factor receptor 2 (HER2)-positive, gross cystic disease fluid protein-15 (GCDFP-15)-positive SDC, with a focus of a typical EMC component at the periphery of the lesion. In the transitional area of the two components, inner ductal cells of double-layered ducts showed similar morphology and immunophenotype to SDC. These findings suggest that SDC originated from the inner ductal cells of EMC. Because the tumor included an EMC as a low-grade carcinoma and an SDC as a high-grade carcinoma, we can consider our case as a dedifferentiated carcinoma as well as a hybrid tumor.

Bcl-2-negative IGH-BCL2 translocation-negative follicular lymphoma of the thyroid differs genetically and epigenetically from Bcl-2-positive IGH-BCL2 translocation-positive follicular lymphoma Aims: Follicular lymphoma (FL), comprising a minor subset of primary thyroid lymphomas, is divided into two groups based on Bcl-2 expression and IGH-BCL2 translocation. The clinicopathological features exhibited by Bcl-2-negative IGH-BCL2 translocation-negative FL of the thyroid (Bcl-2 -/IGH-BCL2 -tFL) are different from those of conventional FL; however, its lymphomagenesis remains unclear. Here, we collected samples from seven patients with Bcl-2 -/IGH-BCL2 -tFL to investigate their epigenetic and genetic aberrations. Methods and results: The immunohistochemical profiles of epigenetic modifiers and the methylation status of histones were examined, including EZH2, MLL2/KMT2D, CBP/CREBBP, EP300, H3K27me3 and H3K4me3, in Bcl-2 -/IGH-BCL2 -tFL and Bcl-2positive IGH-BCL2 translocation-positive FL of the thyroid (Bcl-2 + /IGH-BCL2 + tFL). Most Bcl-2 -/IGH-BCL2 -tFLs retained the positivity of epigenetic modifiers and lower expression of H3K27me3, although Bcl-2 + /IGH-BCL2 + tFLs exhibited aberrant immunohistochemical patterns of EZH2 and CBP/CREBBP and overexpression of H3K27me3. Samples from seven cases were further analysed using targeted sequencing, focusing on the exons of 409 key tumour suppressor genes and oncogenes. Bcl-2 -/IGH-BCL2 -tFLs do not have pathogenic mutations of epigenetic modifiers, such as EZH2, MLL2/KMT2D, MLL3/KMT2C, EP300 and ARID1A, which have been reported in FLs in the literature, whereas Bcl-2 + /IGH-BCL2 + tFLs are probably pathogenic/pathogenic missense mutations or frameshift mutations of these genes. Additionally, novel mutations in TET2 and EP400 were detected in Bcl-2 -/IGH-BCL2 -tFLs. Conclusions: Different genetic and epigenetic abnormalities might be involved in the oncogenesis of Bcl-2 -/IGH-BCL2 -tFLs from Bcl-2 + /IGH-BCL2 + tFLs and other FLs.

No abstract