Mitochondrial diabetes mellitus (MDM) is a genetically heterogeneous disorder caused by mitochondrial DNA (mtDNA) or nuclear DNA mutations, characterized by multi-system involvement and diverse clinical phenotypes. We report a pediatric case presenting with growth retardation followed by subsequent development of diabetes mellitus. Systematic evaluation revealed concurrent bilateral sensorineural hearing loss, bilateral basal ganglia calcification, and electroencephalographic abnormalities. A post-exercise lactate test demonstrated significant elevation of serum lactate levels immediately after physical exertion. Genetic analysis identified a large-scale mitochondrial DNA deletion spanning from m.8649 to m.16084. This case report is complemented by a literature review focusing on the pathogenesis, genetic characteristics, and therapeutic approaches of mitochondrial diabetes, with particular emphasis on mitochondrial disorders exhibiting large-scale mtDNA deletions alongside diabetic manifestations. Our comprehensive analysis aims to enhance clinical understanding and inform diagnostic strategies for this complex disease entity.

Malignant insulinoma is a kind of rare and challenging neuroendocrine tumor. It is often accompanied by distant metastasis, among which liver metastasis is most common, and the prognosis is often non-promising. In this paper, we report a case of multiple liver metastases from malignant insulinoma. The patient, a 70-year-old male, was admitted to the hospital due to "episodic consciousness disorder for more than four months." Blood glucose monitoring revealed recurrent hypoglycemia in the early morning, after meals, and at night. Pancreatic perfusion CT and dynamic enhanced MRI of the liver revealed a mass in the uncinate process of the pancreatic head and multiple liver metastases. Percutaneous liver biopsy confirmed the diagnosis of insulinoma. After multidisciplinary discussions, hepatic artery embolization and radiofrequency ablation were performed in stages, in combination with everolimus treatment. Thereafter, the enhanced CT demonstrated that some liver metastases shrank. The patient had regular meals, and the blood sugar gradually increased and remained normal thereafter. This article discusses this case's clinical characteristics and multidisciplinary collaborative diagnosis and treatment, aiming to provide experience for the comprehensive clinical diagnosis and treatment of malignant insulinoma patients.