SummaryBackground Melasma is a common acquired symmetrical hypermelanosis characterized by irregular light to dark brown macules and patches on sun-exposed areas of the skin. Its histopathological characteristics are not fully understood. Objectives To characterize the histopathological features of facial melasma skin in comparison with adjacent normal skin. Methods Biopsies were taken from both melasma lesional skin and adjacent perilesional normal skin in 56 Korean women with melasma. The sections were stained using haematoxylin and eosin, Fontana±Masson, diastase-resistant periodic acid-Schiff, Masson trichrome and Verhoeff±van Gieson stains, and immunostaining for melanocytes. Data on the changes in number of melanocytes and melanin contents of the epidermis were analysed by a computer-assisted image analysis program. The ultrastructure of the skin was also examined. Results The amount of melanin was signi®cantly increased in all epidermal layers in melasma skin. The staining intensity and number of epidermal melanocytes increased in melasma lesions. Lesional skin showed more prominent solar elastosis compared with normal skin. Melanosomes increased in number and were more widely dispersed in the keratinocytes of the lesional skin. Lesional melanocytes had many more mitochondria, Golgi apparatus, rough endoplasmic reticulum and ribosomes in their cytoplasm. A dihydroxyphenylalanine reaction was apparent in the cisternae and vesicles of the trans-Golgi network in melanocytes from lesional skin. Conclusions Melasma is characterized by epidermal hyperpigmentation, possibly caused both by an increased number of melanocytes and by an increased activity of melanogenic enzymes overlying dermal changes caused by solar radiation.

The TyG index is a simple, cost-effective surrogate marker of insulin resistance among adolescents compared with HOMA-IR.

A simple environmental intervention could effectively influence children. By adding to previously studied strategies, we can develop a more effective obesity prevention program for children.

Pancreatic pseudocyst-portal vein fistulae are a very rare complication of acute or chronic pancreatitis. Another late complication of chronic pancreatitis is pancreatic ascites. We report the case of a 43-year-old man with a spontaneous pseudocyst-portal vein fistula presenting with pancreatic ascites diagnosed by various imaging modalities, in order to emphasize the strength and efficacy of magnetic resonance cholangiopancreatography.

Giant colonic diverticulum is a very rare entity in colonic diverticular disease and is characterized by a high rate of complications such as perforation, abscess formation and even carcinoma. We report a case of a complicated giant diverticulum of the transverse colon accompanied by a right inguinal hernia of the greater omentum in a 52-year-old man, as demonstrated on CT.

Lead shielding curtains are an effective technique to reduce scattered radiation dose in dedicated extremity CBCT, with higher dose reduction closer to the gantry opening.

We aimed to investigate whether the effect of problematic alcohol drinking on hypertension differed according to metabolic health statuses. Male participants from the fifth Korea National Health and Nutrition Examination Survey were recruited. Problematic alcohol drinkers were designated as subjects with heavy drinking (⩾30 g per day), binge drinking (⩾7 glasses per day) or a high alcohol use disorders identification test score (⩾20). Metabolically obese status was defined as having ⩾1 or ⩾2 components of the diagnostic criteria for metabolic syndrome, excluding the blood pressure component. Because the prevalence of problematic alcohol drinking and the prevalence of hypertension largely differed by age groups, separate analyses were performed for the two age groups (<50 and ⩾50 years). Among a total of 6329 subjects, 37.04% had hypertension. In the younger age group, subjects with problematic alcohol drinking demonstrated a higher prevalence of hypertension in both nonobese and obese individuals compared with subjects who were nonobese and who were not problematic alcohol drinkers. Of note, problematic alcohol drinking increased the risk of having hypertension ∼3 times in young nonobese individuals who demonstrated a metabolically obese phenotype compared with those who were metabolically healthy. However, metabolic health status did not have a significant impact on the risk for having hypertension in obese participants, regardless of their age groups. For the prevention of hypertension, avoidance of problematic alcohol drinking should be emphasized, especially in young subjects who show poor metabolic health status despite being nonobese.