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.

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.

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

Lymphoepithelial cysts of the pancreas, which are lined by squamous epithelium and surrounded by mature lymphoid tissue, represent a rare clinicopathologic entity of cystic lesions of the pancreas and true pancreatic cysts. Here, we report a case of lymphoepithelial cyst of the pancreas and a review of the related Korean literature. A 58-year-old man presented to our hospital with an asymptomatic pancreatic mass and no remarkable medical history except hypertension. Physical examination and laboratory analyses showed no abnormalities. Ultrasonography (US) revealed a cystic lesion with heterogeneous internal echo within the body of the pancreas, and computed tomography (CT) revealed a low-density lesion (2.3*.5 cm) with well-defined margins and lobulating contour. To further characterize the mass, a biopsy was collected via endoscopic ultrasonography (EUS)-guided fine-needle aspiration. Histological examination revealed fibrous tissue and epithelial cells, but was insufficient for a definitive diagnosis. Laparotomy revealed that the mass was composed of keratinizing squamous epithelial cells surrounded by lymphoid tissue, thereby confirming the diagnosis of lymphoepithelial cyst of the pancreas
Biopsy ; Biopsy, Fine-Needle ; Endosonography ; Epithelial Cells ; Epithelium ; Humans ; Hypertension ; Keratins ; Laparotomy ; Lymphoid Tissue ; Middle Aged ; Pancreas ; Pancreatic Cyst ; Physical Examination

PURPOSE: Silver-enhanced in situ hybridization (SISH) is a newly developed method to evaluate HER2 gene amplification in invasive breast carcinomas. Most laboratories widely use fluorescence in situ hybridization (FISH) to evaluate the HER2 gene amplification status because FISH is a very sensitive and accurate technique. However, this technique is not the best because it requires specialized equipment and interpretation skills. We compared a new technique of SISH with FISH for assessing HER2 gene amplification in invasive breast carcinomas. METHODS: HER2 gene amplification was assessed in 165 cases of invasive breast carcinoma by FISH and SISH with constructing a tissue microarray. The tumors were assessed by the guidelines of the American Society of Clinical Oncology/College of American Pathologists (ASCO/CAP). Positivity was defined as a HER2/Chromosome 17 ratio greater than 2.2. Negativity was defined if the ratio was less than 1.8. The tumor was considered as equivocal for HER2 gene amplification if the ratio was between 1.8 and 2.2. The HER2 protein status was assessed. Immunostaining for HER2 protein was performed in a Benchmark automatic immunostaining device with using whole tissue sections. RESULTS: There was agreement of the HER2 gene amplification status by SISH and FISH in 162 of 165 cases, which is a concordance rate of 98.2% (kappa=0.94). There were three discrepant cases, with two of them being FISH positive and SISH negative (one case was IHC negative and one case was IHC positive) and one case was FISH negative and SISH equivocal. CONCLUSION: The 98.2% concordance between FISH and SISH meets the ASCO/CAP requirements for test validation of >95% concordance. These results indicate that SISH can be used as an alternative to FISH for assessing the HER2 gene amplification status in breast carcinomas.
Breast ; Breast Neoplasms ; Fluorescence ; Genes, erbB-2 ; In Situ Hybridization ; Receptor, erbB-2

We present here a case of recurrent rectal cancer liver metastasis that was managed with ante situm liver resection under total vascular exclusion (TVE) and venovenous bypass with hypothermic perfusion. A 58-year-old man who suffered with rectal cancer liver metastasis was transferred to our hospital in January 2006. A left lateral sectionectomy had been previously performed. Recurrent lesion developed in segments I, IV and VIII one year after the first hepatectomy. The tumor was 5 cm in diameter and it involved the confluence of the hepatic veins and the retrohepatic vena cava. An incomplete tumor-free margin and massive bleeding were expected with performing a conventional liver resection, together with vena cava reconstruction. Therefore, we planned an ante situm liver resection under TVE and venovenous bypass with hypothermic perfusion. After adhesiolysis, hilar dissection was carried out. The inflow to the medial segment was interrupted, and then the liver and inferior vena cava (IVC) were mobilized fully. During controlling the bleeding of a short hepatic vein, we found adhesion of the hepatocaval portion. Therefore, TVE and venovenous bypass were performed along with suprahepatic IVC transection. The long conduit of V5 was preserved during hepatic parenchymal dissection, and the paracaval portion of the caudate lobe was readily detached from the IVC. The suprahepatic IVC was reconstructed after V5 reconstruction with using the saphenous vein. Portal vein anastomosis was then conducted. After reperfusion, an end-to-side anastomosis was performed between the saphenous vein graft and the IVC. Finally, a Roux-en-Y hepaticojejunostomy was carried out. The patient remains well without recurrence 12 months after the last operation.
Ants ; Hemorrhage ; Hepatectomy ; Hepatic Veins ; Humans ; Liver ; Middle Aged ; Neoplasm Metastasis ; Perfusion ; Portal Vein ; Rectal Neoplasms ; Recurrence ; Reperfusion ; Saphenous Vein ; Transplants ; Vena Cava, Inferior

Cryptococcosis is a disseminated infection caused by Cryptococcus neoformans. It usually causes pulmonary infection and meningitis in immunocompromised patients. However, osteomyelitis due to C. neoformans is extremely rare. It is generally known that cryptococcal osteomyelitis is a complication of disseminated cryptococcosis, appearing in 5-10%. We experienced a case of cryptococcal osteomyelitis with paraspinal abscess in a liver transplant patient.
Abscess ; Cryptococcosis ; Cryptococcus neoformans ; Humans ; Immunocompromised Host ; Liver ; Meningitis ; Osteomyelitis ; Transplants

Cryptococcosis is a disseminated infection caused by Cryptococcus neoformans. It usually causes pulmonary infection and meningitis in immunocompromised patients. However, osteomyelitis due to C. neoformans is extremely rare. It is generally known that cryptococcal osteomyelitis is a complication of disseminated cryptococcosis, appearing in 5-10%. We experienced a case of cryptococcal osteomyelitis with paraspinal abscess in a liver transplant patient.
Abscess ; Cryptococcosis ; Cryptococcus neoformans ; Humans ; Immunocompromised Host ; Liver ; Meningitis ; Osteomyelitis ; Transplants

Maternal serum alpha-fetoprotein (AFP) has been used for a long time for the prenatal diagnosis of neural tube defects in women at midtrimester of gestation. But AFP is elevated not only in cases of neural tube defects, but also in fetus with congenital nephrosis, abdominal wall defects, fetal demise, low birth weight or simply erroneously calculated gestational age. So, when maternal serum AFP is increased, gestational age of the fetus must be re-evaluated and targeted ultrasonographic evaluation is indicated to rule out neural tube defects. If NTDs are suspected or ultrasound is non-diagnostic, amniotic fluid AFP are measured and when AF-AFP is elevated, the presence or absence of acetylcholinesterase should be evaluated. The detection rate of open neural tube defects using amniotic acetylcholiesterase is reported to be as high as 96 to 99% with a 0.06% and 0.14% of false positive rate in amniotic fluids non-contaminated and contaminated by blood, respectively. We report a case with elevated mid-trimester MS-AFP, AF-AFP and positive amniotic acetylcholin-esterase, but in which repeated sonographic findings were normal, and result in delivery of a heathy baby without anomalies.
Abdominal Wall ; Acetylcholinesterase* ; alpha-Fetoproteins ; Amniotic Fluid ; Female ; Fetus ; Gestational Age ; Humans ; Infant, Low Birth Weight ; Infant, Newborn ; Nephrosis ; Neural Tube Defects ; Pregnancy Trimester, Second ; Pregnancy* ; Prenatal Diagnosis ; Ultrasonography

Maternal serum alpha-fetoprotein (AFP) has been used for a long time for the prenatal diagnosis of neural tube defects in women at midtrimester of gestation. But AFP is elevated not only in cases of neural tube defects, but also in fetus with congenital nephrosis, abdominal wall defects, fetal demise, low birth weight or simply erroneously calculated gestational age. So, when maternal serum AFP is increased, gestational age of the fetus must be re-evaluated and targeted ultrasonographic evaluation is indicated to rule out neural tube defects. If NTDs are suspected or ultrasound is non-diagnostic, amniotic fluid AFP are measured and when AF-AFP is elevated, the presence or absence of acetylcholinesterase should be evaluated. The detection rate of open neural tube defects using amniotic acetylcholiesterase is reported to be as high as 96 to 99% with a 0.06% and 0.14% of false positive rate in amniotic fluids non-contaminated and contaminated by blood, respectively. We report a case with elevated mid-trimester MS-AFP, AF-AFP and positive amniotic acetylcholin-esterase, but in which repeated sonographic findings were normal, and result in delivery of a heathy baby without anomalies.
Abdominal Wall ; Acetylcholinesterase* ; alpha-Fetoproteins ; Amniotic Fluid ; Female ; Fetus ; Gestational Age ; Humans ; Infant, Low Birth Weight ; Infant, Newborn ; Nephrosis ; Neural Tube Defects ; Pregnancy Trimester, Second ; Pregnancy* ; Prenatal Diagnosis ; Ultrasonography