This study aimed to determine the prevalence of human epidermal growth factor receptor 2 (HER2)–ultralow breast cancer among cases initially classified as HER2 immunohistochemistry (IHC) 0 and assess interobserver variability in interpreting low-level HER2 expression. Methods: In this multicenter retrospective study, all invasive breast cancer cases diagnosed between January and December 2022 across 10 Korean institutions were retrieved. Institutional pathologists reexamined HER2 IHC slides originally reported as IHC 0 according to the 2018 American Society of Clinical Oncology/College of American Pathologists guidelines and reclassified them as HER2-null (0), HER2-ultralow (0+), or HER2-low (1+). Slides from 10% of HER2-null and HER2-ultralow cases were digitized for central review and independently assessed by two pathologists, with discrepancies resolved by consensus. Results: Among 8,026 cases, 2,836 cases (35.5%) were initially reported as IHC 0. Upon re-review, 1,673 (59.0%), 1,139 (40.2%), and 24 (0.8%) cases were reclassified as HER2-null, HER2-ultralow, and HER2-low, respectively. The prevalence of HER2-ultralow breast cancer varied considerably across institutions (23.7%–78.1%). Central review of 268 digitized cases showed concordance in 193 cases (72.0%). Among the 75 discordant cases, 54 tumors (72.0%) were upgraded from HER2-null to HER2-ultralow, and 18 (24.0%) tumors were upgraded from HER2-ultralow to HER2-low. Furthermore, two tumors (2.7%) were downgraded from HER2-ultralow to HER2-null. Conclusions: Approximately 40% of cases initially categorized as IHC 0 were reclassified as HER2-ultralow. The substantial inter-institutional variability observed in interpreting low-level HER2 expression highlights the need for standardized training and quality assurance to ensure accurate identification of patients eligible for HER2-targeted antibody–drug conjugates.

Echinococcosis, caused by the tapeworm Echinococcus, is rare in Korea and is primarily imported from endemic areas. We report a case of a 37-year-old Korean man with multiple large hepatic cysts, initially diagnosed as simple cysts at a local clinic in 2018. The patient had lived in Oman, an endemic area, for several months in 2016. Upon referral to a tertiary hospital in 2023, due to progressive cyst enlargement, liver magnetic resonance imaging revealed three large cysts with a water lily sign. Serum IgG against Echinococcus was positive by enzyme-linked immunosorbent assay. After diagnosis of echinococcosis, treatment with albendazole and puncture-aspiration-injection-reaspiration (PAIR) was performed.Microscopic and molecular analysis of cyst aspirates confirmed Echinococcus granulosus infection. Follow-up computed tomography demonstrated a reduction in cyst size, yet the emergence of a new right pleural effusion and consolidation in the left lower lobe of the lung necessitated the continuation of albendazole therapy. This case highlights the importance of thorough travel history, imaging findings, and the effectiveness of PAIR combined with albendazole in treating imported echinococcosis.

Echinococcosis, caused by the tapeworm Echinococcus, is rare in Korea and is primarily imported from endemic areas. We report a case of a 37-year-old Korean man with multiple large hepatic cysts, initially diagnosed as simple cysts at a local clinic in 2018. The patient had lived in Oman, an endemic area, for several months in 2016. Upon referral to a tertiary hospital in 2023, due to progressive cyst enlargement, liver magnetic resonance imaging revealed three large cysts with a water lily sign. Serum IgG against Echinococcus was positive by enzyme-linked immunosorbent assay. After diagnosis of echinococcosis, treatment with albendazole and puncture-aspiration-injection-reaspiration (PAIR) was performed.Microscopic and molecular analysis of cyst aspirates confirmed Echinococcus granulosus infection. Follow-up computed tomography demonstrated a reduction in cyst size, yet the emergence of a new right pleural effusion and consolidation in the left lower lobe of the lung necessitated the continuation of albendazole therapy. This case highlights the importance of thorough travel history, imaging findings, and the effectiveness of PAIR combined with albendazole in treating imported echinococcosis.

Echinococcosis, caused by the tapeworm Echinococcus, is rare in Korea and is primarily imported from endemic areas. We report a case of a 37-year-old Korean man with multiple large hepatic cysts, initially diagnosed as simple cysts at a local clinic in 2018. The patient had lived in Oman, an endemic area, for several months in 2016. Upon referral to a tertiary hospital in 2023, due to progressive cyst enlargement, liver magnetic resonance imaging revealed three large cysts with a water lily sign. Serum IgG against Echinococcus was positive by enzyme-linked immunosorbent assay. After diagnosis of echinococcosis, treatment with albendazole and puncture-aspiration-injection-reaspiration (PAIR) was performed.Microscopic and molecular analysis of cyst aspirates confirmed Echinococcus granulosus infection. Follow-up computed tomography demonstrated a reduction in cyst size, yet the emergence of a new right pleural effusion and consolidation in the left lower lobe of the lung necessitated the continuation of albendazole therapy. This case highlights the importance of thorough travel history, imaging findings, and the effectiveness of PAIR combined with albendazole in treating imported echinococcosis.

Echinococcosis, caused by the tapeworm Echinococcus, is rare in Korea and is primarily imported from endemic areas. We report a case of a 37-year-old Korean man with multiple large hepatic cysts, initially diagnosed as simple cysts at a local clinic in 2018. The patient had lived in Oman, an endemic area, for several months in 2016. Upon referral to a tertiary hospital in 2023, due to progressive cyst enlargement, liver magnetic resonance imaging revealed three large cysts with a water lily sign. Serum IgG against Echinococcus was positive by enzyme-linked immunosorbent assay. After diagnosis of echinococcosis, treatment with albendazole and puncture-aspiration-injection-reaspiration (PAIR) was performed.Microscopic and molecular analysis of cyst aspirates confirmed Echinococcus granulosus infection. Follow-up computed tomography demonstrated a reduction in cyst size, yet the emergence of a new right pleural effusion and consolidation in the left lower lobe of the lung necessitated the continuation of albendazole therapy. This case highlights the importance of thorough travel history, imaging findings, and the effectiveness of PAIR combined with albendazole in treating imported echinococcosis.

Purpose: This study aimed to evaluate the long-term clinical outcomes based on the ligation level of the inferior mesenteric artery (IMA) in patients with rectal cancer. Methods: This was a retrospective analysis of a prospectively collected database that included all patients who underwent elective low anterior resection for rectal cancer between January 2013 and December 2019. The clinical outcomes included oncological outcomes, postoperative complications, and functional outcomes. The oncological outcomes included overall survival (OS) and relapse-free survival (RFS). The functional outcomes, including defecatory and urogenital functions, were analyzed using the Fecal Incontinence Severity Index, International Prostate Symptom Score, and International Index of Erectile Function questionnaires. Results: In total, 545 patients were included in the analysis. Of these, 244 patients underwent high ligation (HL), whereas 301 underwent low ligation (LL). The tumor size was larger in the HL group than in the LL group. The number of harvested lymph nodes (LNs) was higher in the HL group than in the LL group. There were no significant differences in complication rates and recurrence patterns between the groups. There were no significant differences in 5-year RFS and OS between the groups. Cox regression analysis revealed that the ligation level (HL vs. LL) was not a significant risk factor for oncological outcomes. Regarding functional outcomes, the LL group showed a significant recovery in defecatory function 1 year postoperatively compared with the HL group. Conclusion LL with LNs dissection around the root of the IMA might not affect the oncologic outcomes comparing to HL; however, it has minimal benefit for defecatory function.

Background: It is well known that a large number of patients with diabetes also have dyslipidemia, which significantly increases the risk of cardiovascular disease (CVD). This study aimed to evaluate the efficacy and safety of combination drugs consisting of metformin and atorvastatin, widely used as therapeutic agents for diabetes and dyslipidemia. Methods: This randomized, double-blind, placebo-controlled, parallel-group and phase III multicenter study included adults with glycosylated hemoglobin (HbA1c) levels >7.0% and <10.0%, low-density lipoprotein cholesterol (LDL-C) >100 and <250 mg/dL. One hundred eighty-five eligible subjects were randomized to the combination group (metformin+atorvastatin), metformin group (metformin+atorvastatin placebo), and atorvastatin group (atorvastatin+metformin placebo). The primary efficacy endpoints were the percent changes in HbA1c and LDL-C levels from baseline at the end of the treatment. Results: After 16 weeks of treatment compared to baseline, HbA1c showed a significant difference of 0.94% compared to the atorvastatin group in the combination group (0.35% vs. −0.58%, respectively; P<0.0001), whereas the proportion of patients with increased HbA1c was also 62% and 15%, respectively, showing a significant difference (P<0.001). The combination group also showed a significant decrease in LDL-C levels compared to the metformin group (−55.20% vs. −7.69%, P<0.001) without previously unknown adverse drug events. Conclusion The addition of atorvastatin to metformin improved HbA1c and LDL-C levels to a significant extent compared to metformin or atorvastatin alone in diabetes and dyslipidemia patients. This study also suggested metformin’s preventive effect on the glucose-elevating potential of atorvastatin in patients with type 2 diabetes mellitus and dyslipidemia, insufficiently controlled with exercise and diet. Metformin and atorvastatin combination might be an effective treatment in reducing the CVD risk in patients with both diabetes and dyslipidemia because of its lowering effect on LDL-C and glucose.

Background: Guidelines for switching to triple combination therapy directly after monotherapy failure are limited. This study investigated the efficacy, long-term sustainability, and safety of either mono or dual add-on therapy using alogliptin and pioglitazone for patients with type 2 diabetes mellitus (T2DM) who did not achieve their target glycemic range with metformin monotherapy. Methods: The Practical Evidence of Antidiabetic Combination Therapy in Korea (PEAK) was a multicenter, placebo-controlled, double-blind, randomized trial. A total of 214 participants were randomized to receive alogliptin+pioglitazone (Alo+Pio group, n=70), alogliptin (Alo group, n=75), or pioglitazone (Pio group, n=69). The primary outcome was the difference in glycosylated hemoglobin (HbA1c) levels between the three groups at baseline to 24 weeks. For durability, the achievement of HbA1c levels <7% and <6.5% was compared in each group. The number of adverse events was investigated for safety. Results: After 24 weeks of treatment, the change of HbA1c in the Alo+Pio, Alo, and Pio groups were –1.38%±0.08%, –1.03%±0.08%, and –0.84%±0.08%, respectively. The Alo+Pio group had significantly lower HbA1c levels than the other groups (P=0.0063, P<0.0001) and had a higher proportion of patients with target HbA1c achievement. In addition, insulin sensitivity and β-cell function, lipid profiles, and other metabolic indicators were also improved. There were no significant safety issues in patients treated with triple combination therapy. Conclusion Early combination triple therapy showed better efficacy and durability than the single add-on (dual) therapy. Therefore, combination therapy with metformin, alogliptin, and pioglitazone is a valuable early treatment option for T2DM poorly controlled with metformin monotherapy.

Tuberculosis of the paranasal sinus is a rare disease caused by infection with Mycobacterium tuberculosis, the causative agent of pulmonary tuberculosis. Although the worldwide incidence of tuberculosis is declining, the diagnosis of primary paranasal tuberculosis remains challenging and cannot be ruled out in patients presenting with refractory chronic rhinosinusitis after adequate surgical and medical treatment. We experienced a case of paranasal tuberculosis with no evidence of previous tuberculosis infection. It was diagnosed after a surgical biopsy revealed granulomatous inflammation and caseous necrosis. The patient responded well to antituberculosis drug therapy and became free of symptoms after 7 months of treatment. We report our findings in this case with a review of the recent literature.