[Clinical, imaging, and pathological characteristics of 35 cases of mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes syndrome].

Objective: To summarize the clinical, imaging, and pathological characteristics of mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes syndrome (MELAS) to improve the diagnosis of this rare disease. Methods: A retrospective case series was conducted to collect the clinical data and results of genetic testing, muscle biopsy, and imaging studies including computed tomography (CT), magnetic resonance imaging (MRI), and magnetic resonance spectroscopy (MRS) of 35 patients with MELAS admitted to the Nanjing Drum Tower Hospital from 2012 to 2021. Descriptive statistical analysis including mean, standard deviation, and frequency percentage were carried out. Results: The average age of onset of the patients was 30.2±2.3 years; the prevalence of family history was 20%. The two main initial symptoms were limb weakness and convulsions. The clinical manifestations of the neuromuscular system were proximal muscle weakness and exercise intolerance. The endocrine system is the most affected outside the neuromuscular system, with diabetes being the most common condition. Among the five patients who underwent brain CT, four showed hypodense lesions and two had calcified lesions. Brain MRI in 26 patients showed that the lesions more often affected the parietal lobe, basal ganglia, temporal lobe, occipital lobe, and frontal lobe than the infratentorial areas. Twelve of these individuals exhibited different levels of brain atrophy. Among the 10 patients who underwent 1H-MRS, nine showed a decrease in N-acetylaspartate (NAA) levels, eight exhibited abnormal lactate elevation (Lac peaks), whereas six had both reduced NAA levels and the presence of Lac peaks. Thirty-one patients underwent genetic testing; among them, 25 were found to have the mt.3243A>G mutation, while the remaining six exhibited rare gene alterations. Muscle biopsies were performed in 21 patients, and 15 showed abnormal mitochondrial proliferation manifested by ragged red fibers and defective oxidative phosphorylation manifested by cytochrome C oxidase (COX) enzyme-deficient muscle fibers. Conclusion: The clinical manifestations of MELAS syndrome are variable and complex, and early atypical symptoms could be missed or misdiagnosed. A detailed clinical history, imaging MRS analysis, muscle biopsy, and genetic testing are necessary to confirm the accurate diagnosis of MELAS.

[Clinicopathological characteristics, MSI and K-ras gene mutations of double primary malignancies associated with colorectal cancer].

Objective: To investigate the clinicopathological characteristics, MSI and K-ras mutation of double primary malignancies (DPM) associated with colorectal cancer (CRC). Methods: From January 2015 to December 2016, the clinicopathological data of CRC patients treated by surgery in the Affiliated Drum Tower Hospital of Nanjing University Medical School were collected, and the clinical data was analyzed. Multiplex real-time fluorescence quantitative PCR and amplification refractory mutation was performed to identify MSI and K-ras gene mutations. Results: Of all patients with CRC, 5.2% (55/1 066) were DPM. There was no significant difference in the male and female ratio, age, colorectal cancer site, T stage, N stage composition ratio between DPM patients with CRC and patients with single CRC (P>0.05). There were significant difference of TNM stage between the two group (P<0.05). The most frequent location of CRC was the colon in both DPM patients with CRC and patients with single CRC[35.5% (359/1 011) and 41.8% (23/55), respectively]. Of 55 DPM patients with CRC, 48 were metachronous DPM patients, 7 were synchronous DPM patients and 41 were colorectal cancer first. In extracolonic organ, digestive system (23/55) was the most commonly occurring system and stomach (11/55) was the most common lesion. DPM patients with CRC had higher incidence of MSI-H than patients with single CRC (P<0.05). There was no significant difference of K-ras gene mutation between DPM patients with CRC and patients with single CRC (P>0.05). MSI-H and K-ras mutation were present in only 2 patients of DPM patients with CRC. Conclusions: The rectum is the most common lesion site in CRC patients. The stomach is the most common extracolonic organ of DPM patients with CRC. DPM patients with CRC has high risk of MSI-H, but no significant difference in the incidence of K-ras mutation.

[Visceral parasitic migration of liver: a clinicopathologic analysis of seven cases].

Objective: To investigate the clinical, radiological and pathological features of visceral parasitic migration of the liver. Methods: Seven cases of visceral parasitic migration of liver were identified at the Affiliated Drum Tower Hospital of Medical School of Nanjing University from January 2008 to July 2017. Clinical data, enhanced CT image and pathological features were analyzed, combining with literature review. Results: There were 5 male and 2 female patients. Five patients presented with abdominal pain or discomfort as the first symptom. Two patients were admitted to the hospital for physical examination with liver nodule. Blood eosinophils were mildly to moderately increased in 4 cases. Enhanced CT showed the liver irregular beaded nodules that showed no significant enhancement of arterial phase. Mild enhancement of round lesions (ring lesion) was seen in a few cases before surgery. By histopathology, the lesions showed central geographic necrosis, surrounded by epithelioid granuloma and inflammatory cell bands. A large number of eosinophils and scattered multinucleated giant cells were found, especially at the peripheral of the lesion. Charcot-Leyden crystals were present in all case and parasitic migrans was found in one case. Conclusions: Visceral parasitic migration of liver is a rare liver disease and is easily misdiagnosed as other benign or malignant liver tumors. Combining clinical data, enhanced CT images and pathological examination can improve the preoperative and postoperative diagnosis of the disease.