Objective: To evaluate the diagnostic performance of the “probable hepatocellular carcinoma (HCC)” category in the Korean Liver Cancer Association-National Cancer Center (KLCA-NCC) v2022 guidelines. Materials and Methods: This multicenter retrospective study included patients at risk of HCC who underwent gadoxetic acid-enhanced MRI between January 2015 and June 2018; a subgroup of these patients also underwent liver CT. Eligible patients had at least one non-cystic lesion (≥10 mm) with a reference standard. Four radiologists interpreted the images independently and the results were pooled. The performance of “definite HCC” and “probable HCC” together and “probable HCC” alone were compared between v2018 and v2022. Results: A total of 2,237 patients (1,666 men; mean age, 59 ± 11 years) with 2,445 lesions were included. In v2022, 1.5% (143/9,780) of the lesions were additionally categorized as “probable HCC” by four reviewers on MRI; among these, 104 lesions were not HCCs. Focal nodular hyperplasia (FNH) or FNH-like nodules constituted 90.4% (94/104) of the false positives. When “definite HCC” and “probable HCC” were combined, v2022 showed higher sensitivity (83.7% [5,670/6,776] vs. 83.1% [5,631/6,776]) but lower specificity (77.1% [2,316/3,004] vs. 80.6% [2,420/3,004]) than v2018 (P < 0.001). For “probable HCC” alone, v2022 showed a lower positive predictive value (PPV) than v2018 (64.1% [373/582] vs. 76.1% [334/439], P < 0.001). In v2022, lesions with non-rim arterial-phase hyperenhancement (APHE) showed a lower PPV than those without APHE (42.3% [91/215] vs. 76.8% [282/367], P < 0.001). In the CT subgroup (n = 1,590), 1.6% (99/6,360) of the lesions were reassessed as “probable HCC,” and its PPV was 83.8% (83/99) in v2022 whereas no lesions were classified as “probable HCC” under v2018. Conclusion The revised “probable HCC” category in the KLCA-NCC v2022 aligns with updates in the diagnostic flow, demonstrating acceptable performance on MRI and CT. Notably, FNH or FNH-like nodules can be misclassified as “probable HCC” when MRI is used.

Purpose: We conducted a randomized prospective trial (KLASS-07 trial) to compare laparoscopy-assisted distal gastrectomy (LADG) and totally laparoscopic distal gastrectomy (TLDG) for gastric cancer. In this interim report, we describe short-term results in terms of morbidity and mortality. Methods: and Methods: The sample size was 442 participants. At the time of the interim analysis, 314 patients were enrolled and randomized. After excluding patients who did not undergo planned surgeries, we performed a modified per-protocol analysis of 151 and 145 patients in the LADG and TLDG groups, respectively. Results: The baseline characteristics, including comorbidity status, did not differ between the LADG and TLDG groups. Blood loss was somewhat higher in the LADG group, but statistical significance was not attained (76.76±72.63 vs. 62.91±65.68 mL; P=0.087). Neither the required transfusion level nor the operation or reconstruction time differed between the 2 groups. The mini-laparotomy incision in the LADG group was significantly longer than the extended umbilical incision required for specimen removal in the TLDG group (4.79±0.82 vs. 3.89±0.83 cm; P<0.001). There were no between-group differences in the time to solid food intake, hospital stay, pain score, or complications within 30 days postoperatively. No mortality was observed in either group. Conclusions Short-term morbidity and mortality rates did not differ between the LADG and TLDG groups. The KLASS-07 trial is currently underway.

Background: Upadacitinib is an oral Janus kinase1 (JAK1)-selective inhibitor, which showed a quick and significant effect on patients with atopic dermatitis in several phase 3 clinical studies. Although, an increasing number of studies have reported data on the real-world efficacy and safety of upadacitinib for the treatment of atopic dermatitis, no studies have yet been published in Korea. Objective: We assessed the real-world efficacy and safety of upadacitinib for the treatment of atopic dermatitis in Korean patients. Methods: A total of 17 patients with atopic dermatitis who received 15 mg of oral upadacitinib everyday for 16 weeks, were included in this retrospective single-center study. Based on electronic medical records, the clinical characteristics, Eczema Area and Severity Index (EASI) score, and adverse events were investigated. Results: The mean EASI score was significantly reduced at 4 weeks of upadacitinib treatment (8.81±9.00) and gradually reduced at week 8 (5.70±7.38), week 12 (4.55±6.23), and week 16 (4.58±6.74) (p＜0.001). At week 16, 61.54%, 30.77%, and 15.38% of patients achieved EASI 75, EASI 90, and EASI 100 responses, respectively. There was no statistically significant difference between EASI 75 and EASI 90 by age or gender at week 16 (p＞0.05). A total of 13 people (76.5%) had adverse events, of which acne was the most common. In all patients, the symptoms were mild and self-limited, and no patient discontinued treatment. Conclusion Upadacitinib was effective and safe for Korean patients with atopic dermatitis in real-world clinical practice.

Background: Adiponectin is an adipose-derived hormone that plays a role in various metabolic diseases. We previously demonstrated that adiponectin inhibits melanin synthesis through adenosine monophosphate-activated protein kinase (AMPK) activation in melanocytes. However, melanocytes can be affected by neighboring keratinocytes, and the effect of adiponectin on these functional units has not been investigated. Objective: We investigated the effect of adiponectin on melanogenesis in co-cultured models of normal human melanocytes (NHMs), normal human keratinocytes (NHKs), and human dermal fibroblasts (HDFs), and the effect of adiponectin on melanin content in human skin tissues. Methods: Quantitative real-time polymerase chain reaction (qPCR) was performed for tyrosinase and microphthalmia-associated transcription factor (MITF). The degree of phosphorylation of AMPK, cAMP response element binding protein (CREB), and AKT was evaluated by western blot assay, and Fontana-Masson staining was performed on cultured human skin tissues. Results: Adiponectin decreased the melanin content in the co-culture models of NHMs with NHKs, NHMs with HDFs, and NHMs with both NHKs and HDFs. qPCR revealed that both tyrosinase and MITF were decreased after adiponectin treatment in the co-culture system. Following adiponectin treatment, AMPK was activated in all cell groups; however, the phosphorylation of CREB was decreased in HDFs and NHKs. The phosphorylation of AKT was decreased in only NHMs. In the experiment with human skin tissues cultured ex vivo, the densitometric analysis of Fontana-Masson staining revealed that adiponectin treatment reduced the melanin level of ultraviolet-irradiated human skin tissues. Conclusion Adiponectin inhibited melanogenesis in both co-culture models and human skin tissues ex vivo.

A case of persistent Ralstonia mannitolilytica bacteremia in the neonatal intensive care unit prompted source investigation due to its rarity. After an extensive investigation, a contaminated ultrasonic nebulizer was identified as the source, and the infection was controlled by removing the source. This study emphasizes the importance of further investigations, even in single cases of rare pathogens.

Concerns about the effectiveness of current vaccines against the rapidly spreading severe acute respiratory syndrome-coronavirus-2 omicron (B.1.1.529) variant are increasing. This study aimed to assess neutralizing antibody activity against the wild-type (BetaCoV/Korea/ KCDC03/2020), delta, and omicron variants after full primary and booster vaccinations with BNT162b2. A plaque reduction neutralization test was employed to determine 50% neutralizing dilution (ND 50 ) titers in serum samples. ND 50 titers against the omicron variant (median [interquartile range], 5.3 [< 5.0–12.7]) after full primary vaccination were lower than those against the wild-type (144.8 [44.7–294.0]) and delta (24.3 [14.3–81.1]) variants.Furthermore, 19/30 participants (63.3%) displayed lower ND 50 titers than the detection threshold (< 10.0) against omicron after full primary vaccination. However, the booster vaccine significantly increased ND 50 titers against BetaCoV/Korea/KCDC03/2020, delta, and omicron, although titers against omicron remained lower than those against the other variants (P < 0.001). Our study suggests that booster vaccination with BNT162b2 significantly increases humoral immunity against the omicron variant.

Background: Nipple adenoma (NA) is a rare benign tumor arising in the lactiferous ducts of the nipple. It typically presents as a palpable nodule, erosion, or discharge with erythema of the nipple. NA is different from other mammary proliferative diseases of the nipple; however, its clinicopathologic characteristics have been scarcely elucidated. Objective: In this study, we aimed to assess the clinical and histopathological characteristics of NA and compare them with mammary Paget’s diseases and breast carcinomas of the nipple. Methods: We retrospectively reviewed fifteen patients with NA. Furthermore, we reviewed fifteen patients with nipple Paget’s diseases and five patients with breast carcinomas (ductal carcinoma in situ and invasive ductal carcinoma). Skin lesions’ clinical characteristics and general histopathological findings were investigated. Results: NA showed significantly early onset (p=0.014), delayed time for onset to diagnosis (p=0.026), and smaller lesion than other nipple malignant diseases (p＜0.001). NA was predominantly localized on the right side and exhibited as more palpable mass and less nipple discharge as initial symptoms. Estimated prevalence of Korean cases (0.026%) was twice higher than Western countries (0.012%). p16 immunostaining in NA and other malignant diseases did not differ. Conclusion NA is a benign neoplasm arising on the nipple. NA showed earlier onset with smaller size at initial presentation than other malignant diseases which presented more crusts. Unnecessary surgical procedures for NA should be avoided with preceding clinical differential diagnosis.

Background: Nilotinib is a tyrosine kinase inhibitor approved by the Ministry of Food and Drug Safety for frontline and 2nd line treatment of Philadelphia chromosome-positive chronic myeloid leukemia (Ph+ CML). This study aimed to confirm the safety and efficacy of nilotinib in routine clinical practice within South Korea. Methods: An open-label, multicenter, single-arm, 12-week observational post-marketing surveillance (PMS) study was conducted on 669 Korean adult patients with Ph + CML from December 24, 2010, to December 23, 2016. The patients received nilotinib treatment in routine clinical practice settings. Safety was evaluated by all types of adverse events (AEs) during the study period, and efficacy was evaluated by the complete hematological response (CHR) and cytogenetic response. Results: During the study period, AEs occurred in 61.3% (410 patients, 973 events), adverse drug reactions (ADRs) in 40.5% (271/669 patients, 559 events), serious AEs in 4.5% (30 patients, 37 events), and serious ADRs in 0.7% (5 patients, 8 events). Furthermore, unexpected AEs occurred at a rate of 6.9% (46 patients, 55 events) and unexpected ADRs at 1.2% (8 patients, 8 events). As for the efficacy results, CHR was achieved in 89.5% (442/494 patients), and minor cytogenetic response or major cytogenetic response was achieved in 85.8% (139/162 patients). Conclusion This PMS study shows consistent results in terms of safety and efficacy compared with previous studies. Nilotinib was well tolerated and efficacious in adult Korean patients with Ph + CML in routine clinical practice settings.

Background: Riehl’s melanosis of the face and neck has been reported in middle-aged women who have darker skin types. Recently, cases of Riehl’s melanosis have been on the rise in Korea, which might reflect the increased use of various cosmetic products and procedures. Objective: This study was designed to analyze the clinicopathological characteristics and treatment outcomes of Riehl’s melanosis in Korean patients. Methods: We closely observed 80 patients with Riehl’s melanosis diagnosed in Asan Medical Center and Hanyang University Medical Center between 2005 and 2015. A skin biopsy was analyzed in 51 patients, and a patch test was carried out in 16 patients. Results: Patients with chronic Riehl’s melanosis (＞12 months) had an increased frequency of previous laser treatments. Patients with acute Riehl’s melanosis (＜3 months) reported a previous history of dry skin, itching, or irritation as a result of the use of hair dye. Patients older than 50 years, with darker skin type, and with a longer disease duration (＞12 months) had poor response rates. Chronic Riehl’s melanosis may be preceded by repeated irritation of barrier-compromised skin, and acute Riehl’s melanosis seems to be an allergic form of Riehl’s melanosis. Conclusion Riehl’s melanosis has different clinical manifestations according to disease duration and different treatment responses based on disease duration.

Background: Complementary and alternative medicine (CAM) has been used frequently, and its use continues to increase in lung cancer patients, despite insufficient scientific of its efficacy. To investigate this situation, we analyzed the current awareness and use of CAM in Korean lung-cancer patients. Methods: This prospective survey–based study was performed at seven medical centers in South Korea between August and October 2019. The survey assessed general patient characteristics and the awareness and use of CAM. We analyzed differences in the clinical parameters of patients aware and not aware of CAM and of CAM non-users and users. Results: Of the 434 patients included in this study, 68.8% responded that they were aware of CAM and 30.9% said they had experienced it. In univariate analysis, the patients aware of CAM were younger with poor performance status, had advanced-stage lung cancer, received more systemic therapy, and received concurrent chemoradiation therapy (CCRT). By multiple logistic regression, younger age, poor performance status, advanced stage, and prior CCRT were identified as independent risk factors for CAM awareness. There were no significant differences in the general characteristics and cancer-associated clinical parameters of CAM non-users and users. Conclusion Specific clinical parameters were associated with patients’ awareness of CAM, although there were no significantly different characteristics between CAM users and non-users.