Purpose: Notable effectiveness of trastuzumab deruxtecan in patients with human epidermal growth factor receptor 2 (HER2)–low advanced breast cancer (BC) has focused pathologists’ attention. We studied the incidence and clinicopathologic characteristics of HER2-low BC, and the effects of immunohistochemistry (IHC) associated factors on HER2 IHC results. Materials and Methods: The Breast Pathology Study Group of the Korean Society of Pathologists conducted a nationwide study using real-world data on HER2 status generated between January 2022 and December 2022. Information on HER2 IHC protocols at each participating institution was also collected. Results: Total 11,416 patients from 25 institutions included in this study. Of these patients, 40.7% (range, 6.0% to 76.3%) were classified as HER2-zero, 41.7% (range, 10.5% to 69.1%) as HER2-low, and 17.5% (range, 6.7% to 34.0%) as HER2-positive. HER2-low tumors were associated with positive estrogen receptor and progesterone receptor statuses (p < 0.001 and p < 0.001, respectively). Antigen retrieval times (≥ 36 minutes vs. < 36 minutes) and antibody incubation times (≥ 12 minutes vs. < 12 minutes) affected on the frequency of HER2 IHC 1+ BC at institutions using the PATHWAY HER2 (4B5) IHC assay and BenchMark XT or Ultra staining instruments. Furthermore, discordant results between core needle biopsy and subsequent resection specimen HER2 statuses were observed in 24.1% (787/3,259) of the patients. Conclusion The overall incidence of HER2-low BC in South Korea concurs with those reported in previously published studies. Significant inter-institutional differences in HER2 IHC protocols were observed, and it may have impact on HER2-low status. Thus, we recommend standardizing HER2 IHC conditions to ensure precise patient selection for targeted therapy.

Nivolumab plus chemotherapy in the first-line setting has demonstrated clinical efficacy in patients with human epidermal growth factor receptor 2–negative advanced or metastatic gastric cancer, and is currently indicated as a standard treatment. Programmed death-ligand 1 (PD-L1) expression is an important biomarker for predicting response to anti–programmed death 1/PD-L1 agents in several solid tumors, including gastric cancer. In the CheckMate-649 trial, significant clinical improvements were observed in patients with PD-L1 combined positive score (CPS) ≥ 5, determined using the 28-8 pharmDx assay. Accordingly, an accurate interpretation of PD-L1 CPS, especially at a cutoff of 5, is important. The CPS method evaluates both immune and tumor cells and provides a comprehensive assessment of PD-L1 expression in the tumor microenvironment of gastric cancer. However, CPS evaluation has several limitations, one of which is poor interobserver concordance among pathologists. Despite these limitations, clinical indications relying on PD-L1 CPS are increasing. In response, Korean gastrointestinal pathologists held a consensus meeting for the interpretation of PD-L1 CPS in gastric cancer. Eleven pathologists reviewed 20 PD-L1 slides with a CPS cutoff close to 5, stained with the 28-8 pharmDx assay, and determined the consensus scores. The issues observed in discrepant cases were discussed. In this review, we present cases of gastric cancer with consensus PD-L1 CPS. In addition, we briefly touch upon current practices and clinical issues associated with assays used for the assessment of PD-L1 expression in gastric cancer.

Background: Korea recently established 70 emergency medical service areas. However, there are many concerns that medical resources for stroke could not be evenly distributed through the country. We aimed to compare the treatment quality and outcomes of acute stroke among the emergency medical service areas. Methods: This study analyzed the data of 28,800 patients admitted in 248 hospitals which participated in the 8th acute stroke quality assessment by Health Insurance Review and Assessment Service. Individual hospitals were regrouped into emergency service areas according to the address of the location. Assessment indicators and fatality were compared by the service areas. We defined the appropriate hospital by the performance of intravenous thrombolysis. Results: In seven service areas, there were no hospitals which received more than 10 stroke patients for 6 months. In nine service areas, there were no patients who underwent intravenous thrombolysis (IVT). Among 167 designated emergency medical centers, 50 hospitals (29.9%) responded that IVT was impossible 24 hours a day. There are 97 (39.1%) hospitals that meet the definitions of appropriate hospital. In 23 service areas (32.9%) had no appropriate or feasible hospitals. The fatality of service areas with stroke centers were 6.9% within 30 days and 15.6% within 1 year from stroke onset than those without stroke centers (7.7%, 16.9%, respectively). Conclusions There was a wide regional gap in the medical resource and the quality of treatments for acute stroke among emergency medical service areas in Korea. The poststroke fatality rate of the service areas which have stroke centers or appropriate hospitals were significantly low.

BACKGROUND/AIMS: Primary hyperparathyroidism can be cured by minimally invasive surgery (MIS) with optimized preoperative localization. Ultrasonography (US) and 99mTc-sestamibi (MIBI) scan are the imaging modalities most widely used for the localization of the affected glands. In this study, we defined the roles of US and MIBI scan. METHODS: We retrospectively reviewed 40 patients who underwent parathyroidectomy for a single parathyroid adenoma between 2004 and 2013. US and scintigraphic findings were compared with operative findings. RESULTS: Adenomas were accurately localized using US and MIBI scan in 38 patients (95%) and 37 patients (92.5%), respectively. Twenty-nine patients (76.3%) showed typical extrathyroidal hypoechoic nodule with central or peripheral vascularity, and, after MIS, we confirmed that they were suffering from a single parathyroid adenoma. Eight patients with atypical US findings and two patients with an undetectable lesion on US underwent MIS after localization using MIBI scan or computed tomography (CT). Only one patient showed an extrathyroidal cystic nodule evidenced by high parathyroid hormone cystic fluid on ultrasound-guided fine-needle aspiration and negative MIBI scan. All lesions not localized on US were located in the superior portion. CONCLUSIONS: US is a sensitive and accurate method for the preoperative localization of parathyroid adenoma, especially if the lesion has typical US features and is located inferiorly. We suggest that US be the first localization modality and that MIBI scan or CT be used in the limited number of cases with negative US findings.
Adenoma ; Biopsy, Fine-Needle ; Humans ; Hyperparathyroidism ; Hyperparathyroidism, Primary ; Parathyroid Hormone ; Parathyroid Neoplasms* ; Parathyroidectomy ; Retrospective Studies ; Surgical Procedures, Minimally Invasive ; Technetium Tc 99m Sestamibi* ; Ultrasonography*

A 14-year-old, 7.4 kg, neutered male mongrel dog presented with vomiting, anorexia, and hematuria starting 3 days prior to admission. Serum biochemical profiles indicated severe azotemia. Computed tomography revealed loss of normal left kidney structure. The organ was 1.5 to 2 times larger than the right kidney with mixed attenuation. Histopathologic examination was performed after nephrectomy. The renal mass and mesenteric membrane were positive for vimentin and stained blue with Masson's trichrome. In conclusion, this was a rare occurrence of primary renal fibrosarcoma, most likely originated from the renal capsule, with local invasion into the mesenteric membrane.
Adolescent ; Animals ; Anorexia ; Azotemia ; Dogs* ; Fibrosarcoma* ; Hematuria ; Humans ; Kidney ; Male ; Membranes* ; Nephrectomy ; Vimentin ; Vomiting

Hepatoid adenocarcinoma of the stomach (HAS) is a rare form of gastric cancer that histologically resembles hepatocellular carcinoma and is characterized by large amounts of alpha fetoprotein in the serum. The prognosis of HAS is poor compared to that of primary gastric cancer with five-year survival rates of 9% and 44%, respectively. Here, we report five patients diagnosed with HAS. Our experience suggests that an advanced stage of HAS has an extremely poor prognosis, but early detection and radical surgery can help improve the prognosis of the disease.
Adenocarcinoma* ; alpha-Fetoproteins ; Carcinoma, Hepatocellular ; Humans ; Prognosis ; Stomach ; Stomach Neoplasms ; Survival Rate

PURPOSE: There are two surgical procedures for proximal early gastric cancer (EGC): total gastrectomy (TG) and proximal gastrectomy (PG). This study aimed to compare the long-term outcomes of PG with those of TG. MATERIALS AND METHODS: Between January 2001 and December 2008, 170 patients were diagnosed with proximal EGC at Soonchunhyang University Cheonan Hospital, of which 64 patients underwent PG and 106 underwent TG. Clinicopathologic features, postoperative complications, blood chemistry data, changes in body weight, and oncological outcomes were analyzed and retrospectively compared between both groups. RESULTS: Tumor size was smaller and the number of retrieved lymph nodes was lower in the PG group. The postoperative complication rate was 10.9% in the TG group and 16.9% in the PG group. The incidence of Los Angeles grade C and D reflux esophagitis was significantly higher in the TG group. Hemoglobin level was higher and body weight loss was greater in the TG group at 2, 3, and 5 years postoperatively. The albumin levels at 3 and 5 years were lower in the TG group. There was no significant difference in the 5-year overall survival rates between the two groups (P=0.789). CONCLUSIONS: Postoperative complications and oncologic outcomes were observed to be similar between the two groups. The PG group showed better laboratory data and weight loss than did the TG group. Moreover, severe reflux esophagitis occurred less frequently in the PG group than in the TG group. PG can be considered as an effective surgical treatment for proximal EGC.
Body Weight ; Chemistry ; Chungcheongnam-do ; Esophagitis, Peptic ; Gastrectomy* ; Humans ; Incidence ; Lymph Nodes ; Postoperative Complications ; Retrospective Studies ; Stomach Neoplasms* ; Survival Rate ; Weight Loss

BACKGROUND/AIMS: The aims of this study were to evaluate the efficacy and safety of ultrasound-guided percutaneous ethanol ablation for benign cystic thyroid nodules, and to identify the clinical factors associated with therapeutic outcome. METHODS: We examined 46 patients with benign cystic nodules. After removal of cystic fluid, 99% ethanol was injected under ultrasound guidance. Follow-up ultrasonography was then performed 2 weeks and 6-36 months after the therapy to evaluate the early and late response, respectively. An effective response (ER) was defined as volume reduction > 50% or the absence of any residual cystic lesion; partial response (PR) as a 25-50% volume reduction; and no response (NR) as volume reduction < 25% or a volume expansion. RESULTS: During the early response, ER, PR, and NR were 67.4, 30.4, and 2.2%, respectively. The initial mean cyst volume of 12.0 +/- 7.8 mL (3.4-41.3) was reduced significantly after ethanol ablation therapy to 5.4 +/- 3.2 mL (0-33.0; 55% volume reduction, p < 0.001), and to a final late response volume of 4.4 +/- 3.4 mL (0-23.3; 63% volume reduction, p < 0.01). Except for 6 patients who received additional ethanol injection therapies, ER was obtained in 31 of 40 (77.5%) patients in the late response. A large initial volume was the factor associated with therapeutic failure (p = 0.04). Eleven patients (23%) reported transient mild local pain. CONCLUSIONS: Ultrasound-guided ethanol ablation is a safe and highly effective therapeutic method for cystic thyroid nodules. However, more sophisticated approaches are needed for large cystic nodules.
Ethanol* ; Follow-Up Studies ; Humans ; Methods ; Thyroid Gland* ; Thyroid Nodule* ; Ultrasonography

A 53-year-old woman was diagnosed with gastrointestinal stromal tumor (GIST) of the stomach. Computed tomography (CT) revealed a huge mass (12 cm in diameter), likely to invade pancreas and spleen. In the operation field, the tumor was in an unresectable state. The patient was then started on imatinib therapy for 4 months. On follow-up imaging studies, the tumor almost disappeared. We performed total gastrectomy and splenectomy upon which two small-sized residual tumors were found on microscopy. In this paper, we describe a case of clinicopathologic change in unresectable GIST after neoadjuvant imatinib mesylate.
Benzamides ; Female ; Follow-Up Studies ; Gastrectomy ; Gastrointestinal Stromal Tumors ; Humans ; Imatinib Mesylate ; Mesylates ; Microscopy ; Middle Aged ; Neoplasm, Residual ; Pancreas ; Piperazines ; Pyrimidines ; Spleen ; Splenectomy ; Stomach

We experienced a case of acute myocarditis as the initial presentation of Crohn's disease. A 19-year-old woman was admitted with impaired consciousness, shock, and respiratory failure. She had suffered from frequent diarrhea and abdominal pain for several years. Cardiac troponin I and creatine kinase-MB fraction levels were elevated to 5.32 and 16.66 ng/mL, respectively. A 12-lead electrocardiogram showed sinus tachycardia, and a chest radiograph revealed interstitial pulmonary edema. An echocardiogram showed dilated ventricles with akinesia of the basal to apical inferoseptal, anteroseptal, anterior, and inferior left ventricular walls and severely impaired systolic function. Intensive care with inotropic support was effective, and her clinical condition gradually improved. Two weeks later, a colonoscopy revealed ulceration with stenosis in the terminal ileum and multiple aphthous ulcers in the rectum. A biopsy of the rectum revealed non-caseating granulomatous inflammation. She was diagnosed with Crohn's disease presenting with acute myocarditis.
Abdominal Pain ; Biopsy ; Colonoscopy ; Consciousness ; Constriction, Pathologic ; Creatine ; Crohn Disease ; Diarrhea ; Electrocardiography ; Female ; Humans ; Ileum ; Inflammation ; Myocarditis ; Pulmonary Edema ; Rectum ; Respiratory Insufficiency ; Shock ; Stomatitis, Aphthous ; Tachycardia, Sinus ; Thorax ; Troponin I ; Ulcer ; Young Adult ; Critical Care