Acute necrotizing encephalopathy (ANE) is a rare immune-mediated complication of a viral infection commonly involving the bilateral thalamus and has been reported mainly in children. Here, we describe the MRI findings of coronavirus disease 2019 (COVID-19)-associated ANE in two pediatric patients, including a 7-year-old girl with fever and mental change, and a 6-year-old girl with fever and generalized seizures. Brain MRI revealed symmetrical T2 fluid attenuated inversion recovery high-signal intensity lesions in the bilateral thalamus with central hemorrhage. In one patient, the thalamic lesions showed a trilaminar pattern on the apparent diffusion coefficient map. This report emphasizes the importance of creating awareness regarding these findings in patients with COVID-19, particularly in children with severe neurological symptoms. Furthermore, it provides a literature review of several documented cases of COVID-19 presenting with bilateral thalamic hemorrhagic necrosis, suggesting a diagnosis of ANE.

Kimura’s disease (KD) is a rare, chronic inflammatory disorder characterized by angiolymphoid hyperplasia, peripheral eosinophilia, and elevated serum immunoglobulin E levels. It primarily affects young Asian males and typically involves the head and neck region, especially near the mandible and postauricular regions. Orbital involvement is unusual and extraocular muscle (EOM) involvement is exceedingly rare, with only a few cases reported in the literature. The present report describes a case of surgically confirmed KD in a 16-yearold male, involving the bilateral EOM, lacrimal gland, and left parotid gland.

Acute necrotizing encephalopathy (ANE) is a rare immune-mediated complication of a viral infection commonly involving the bilateral thalamus and has been reported mainly in children. Here, we describe the MRI findings of coronavirus disease 2019 (COVID-19)-associated ANE in two pediatric patients, including a 7-year-old girl with fever and mental change, and a 6-year-old girl with fever and generalized seizures. Brain MRI revealed symmetrical T2 fluid attenuated inversion recovery high-signal intensity lesions in the bilateral thalamus with central hemorrhage. In one patient, the thalamic lesions showed a trilaminar pattern on the apparent diffusion coefficient map. This report emphasizes the importance of creating awareness regarding these findings in patients with COVID-19, particularly in children with severe neurological symptoms. Furthermore, it provides a literature review of several documented cases of COVID-19 presenting with bilateral thalamic hemorrhagic necrosis, suggesting a diagnosis of ANE.

Kimura’s disease (KD) is a rare, chronic inflammatory disorder characterized by angiolymphoid hyperplasia, peripheral eosinophilia, and elevated serum immunoglobulin E levels. It primarily affects young Asian males and typically involves the head and neck region, especially near the mandible and postauricular regions. Orbital involvement is unusual and extraocular muscle (EOM) involvement is exceedingly rare, with only a few cases reported in the literature. The present report describes a case of surgically confirmed KD in a 16-yearold male, involving the bilateral EOM, lacrimal gland, and left parotid gland.

Acute necrotizing encephalopathy (ANE) is a rare immune-mediated complication of a viral infection commonly involving the bilateral thalamus and has been reported mainly in children. Here, we describe the MRI findings of coronavirus disease 2019 (COVID-19)-associated ANE in two pediatric patients, including a 7-year-old girl with fever and mental change, and a 6-year-old girl with fever and generalized seizures. Brain MRI revealed symmetrical T2 fluid attenuated inversion recovery high-signal intensity lesions in the bilateral thalamus with central hemorrhage. In one patient, the thalamic lesions showed a trilaminar pattern on the apparent diffusion coefficient map. This report emphasizes the importance of creating awareness regarding these findings in patients with COVID-19, particularly in children with severe neurological symptoms. Furthermore, it provides a literature review of several documented cases of COVID-19 presenting with bilateral thalamic hemorrhagic necrosis, suggesting a diagnosis of ANE.

Kimura’s disease (KD) is a rare, chronic inflammatory disorder characterized by angiolymphoid hyperplasia, peripheral eosinophilia, and elevated serum immunoglobulin E levels. It primarily affects young Asian males and typically involves the head and neck region, especially near the mandible and postauricular regions. Orbital involvement is unusual and extraocular muscle (EOM) involvement is exceedingly rare, with only a few cases reported in the literature. The present report describes a case of surgically confirmed KD in a 16-yearold male, involving the bilateral EOM, lacrimal gland, and left parotid gland.

Stroke causes systemic immunosuppression. T lymphocytes are involved in infarct size in the early stages of stroke. However, the phenotypes of T lymphocytes and their functions in peripheral immune organs and the brain have not been well analyzed in the acute and chronic phases of stroke. Here, we investigated pathological phenotypic alterations in the systemic immune response, especially changes in T lymphocytes, from one day to six months after ischemic stroke in mice. Impairment in thymocyte numbers, development, proliferation, and apoptosis were observed for up to two weeks. The number of mature T cells in the spleen and blood decreased and showed reduced interferon-γ production. Increased numbers of CD4-CD8-CD3+ double-negative T cells were observed in the mouse brain during the early stages of stroke, whereas interleukin (IL)-10+Foxp3+ regulatory T lymphocytes increased from two weeks during the chronic phase. These phenotypes correlated with body weight and neurological severity scores. The recovery of T lymphocyte numbers and increases in IL-10+Foxp3+ regulatory T lymphocytes may be important for long-term neurological outcomes. Dynamic changes in T lymphocytes between the acute and chronic phases may play different roles in pathogenesis and recovery. This study provides fundamental information regarding the T lymphocyte alterations from the brain to the peripheral immune organs following stroke.

Pleomorphic adenoma is the most common benign neoplasm of the salivary glands. Its three malignant variants include carcinoma ex pleomorphic adenoma, carcinosarcoma, and metastasizing pleomorphic adenoma. Among the subtypes of carcinoma ex pleomorphic adenoma, high-grade mucoepidermoid carcinoma has rarely been reported. Additionally, metastasizing pleomorphic adenoma is rare.We report the imaging findings of a high-grade mucoepidermoid carcinoma ex metastasizing pleomorphic adenoma of the parotid gland and parapharyngeal space in a 42-year-old man.

Stroke causes systemic immunosuppression. T lymphocytes are involved in infarct size in the early stages of stroke. However, the phenotypes of T lymphocytes and their functions in peripheral immune organs and the brain have not been well analyzed in the acute and chronic phases of stroke. Here, we investigated pathological phenotypic alterations in the systemic immune response, especially changes in T lymphocytes, from one day to six months after ischemic stroke in mice. Impairment in thymocyte numbers, development, proliferation, and apoptosis were observed for up to two weeks. The number of mature T cells in the spleen and blood decreased and showed reduced interferon-γ production. Increased numbers of CD4-CD8-CD3+ double-negative T cells were observed in the mouse brain during the early stages of stroke, whereas interleukin (IL)-10+Foxp3+ regulatory T lymphocytes increased from two weeks during the chronic phase. These phenotypes correlated with body weight and neurological severity scores. The recovery of T lymphocyte numbers and increases in IL-10+Foxp3+ regulatory T lymphocytes may be important for long-term neurological outcomes. Dynamic changes in T lymphocytes between the acute and chronic phases may play different roles in pathogenesis and recovery. This study provides fundamental information regarding the T lymphocyte alterations from the brain to the peripheral immune organs following stroke.

Pleomorphic adenoma is the most common benign neoplasm of the salivary glands. Its three malignant variants include carcinoma ex pleomorphic adenoma, carcinosarcoma, and metastasizing pleomorphic adenoma. Among the subtypes of carcinoma ex pleomorphic adenoma, high-grade mucoepidermoid carcinoma has rarely been reported. Additionally, metastasizing pleomorphic adenoma is rare.We report the imaging findings of a high-grade mucoepidermoid carcinoma ex metastasizing pleomorphic adenoma of the parotid gland and parapharyngeal space in a 42-year-old man.