Evaluation of copper alloys for reducing infection by methicillin resistant Staphylococcus aureus and vancomycin resistant Enterococcus faecium in intensive care unit and in vitro

Background/Aims@#Multi-drug resistant pathogens are increasing among healthcare-associated infections. It is well known that copper and copper alloys have antimicrobial activity. We evaluated the activity of copper against bacteria in a hospital setting in Korea. @*Methods@#This study was conducted in a laboratory and medical intensive care unit (ICU). Methicillin resistant Staphylococcus aureus (MRSA) and vancomycin resistant Enterococcus faecium (VRE) were inoculated onto copper, copper alloy and stainless steel plates. After 24 hours of incubation, colony-forming units (CFU) were counted in the laboratory. Two similar rooms were chosen in the ICU; one room had copper-containing surface, and the other room contained items with a stainless steel surfaces. Items were sampled weekly for 8 weeks when the rooms were not crowded and when the rooms were busier with healthcare workers or visitors. @*Results@#In vitro time-kill curves showed copper or, a copper alloy yielded a significant reduction in MRSA and VRE CFUs over 15 minutes. Upon exposure to stainless steel plates, CFUs were slowly reduced for 24 hours. In vivo, MRSA CFUs were lower in rooms with copper-containing surfaces compared with controls, both after cleaning and after patients had received visitors (p < 0.05). Analysis of VRE revealed similar results, but VRE CFUs from copper-containing surfaces of drug carts in the ICU did not decrease significantly. @*Conclusions@#Copper has antimicrobial activity and appears to reduce the number of multi-drug resistant microorganisms in a hospital environment. This finding suggests the potential of the use of copper fittings, instruments and surfaces in hospital.

The Experience of RHD Genotyping in D-negative Blood Donors / 대한수혈학회지

Background@#There have been some domestic and overseas cases of anti-D alloimmunization caused by the transfusion of serologically D-negative blood. However, it is difficult to distinguish between true D-negative and DEL variants using conventional serologic typing. Therefore, we established the RHD genotyping algorithm for the detection of DEL variants and applied this algorithm to serologic D negative donors who voluntarily consented to testing. @*Methods@#From September 2016 to December 2020, 216 RHD negative donors who were C＋ and/or E+ in previous serologic typing were recruited. The screening test was PCR amplification of the RHD exons 4, 7, 10, and a promotor. Based on the results of PCR screening, true D-negative samples and RHD variants (including DEL) were discriminated. When the result was a RHD variant, exon 9 was sequenced to identify the nucleotide changes. Full sequencing was performed if no mutations were detected at exon 9. @*Results@#Among the 216 participants, 39 cases with the C−E−c＋e＋ phenotypes that did not meet the recruitment criteria were excluded from data analysis. Among the remaining 177 samples, 68 cases (38.4%) were RHD total deletions, 35 cases (19.8%) were RHD-CE-D hybrids, and 74 cases (41.8%) were RHD variants. Among the cases of RHD variants, 73 cases (98.6%) had c.1227G＞A substitutions and were confirmed as Asian-type DEL. @*Conclusion@#Seventy-four cases of serologic D negative donors were reclassified as RHD variants by RHD genotyping. This is believed to have contributed to the improvement of transfusion safety by lowering the risk of anti-D alloimmunization in D-negative patients.

Evaluation of copper alloys for reducing infection by methicillin resistant Staphylococcus aureus and vancomycin resistant Enterococcus faecium in intensive care unit and in vitro

Background/Aims@#Multi-drug resistant pathogens are increasing among healthcare-associated infections. It is well known that copper and copper alloys have antimicrobial activity. We evaluated the activity of copper against bacteria in a hospital setting in Korea. @*Methods@#This study was conducted in a laboratory and medical intensive care unit (ICU). Methicillin resistant Staphylococcus aureus (MRSA) and vancomycin resistant Enterococcus faecium (VRE) were inoculated onto copper, copper alloy and stainless steel plates. After 24 hours of incubation, colony-forming units (CFU) were counted in the laboratory. Two similar rooms were chosen in the ICU; one room had copper-containing surface, and the other room contained items with a stainless steel surfaces. Items were sampled weekly for 8 weeks when the rooms were not crowded and when the rooms were busier with healthcare workers or visitors. @*Results@#In vitro time-kill curves showed copper or, a copper alloy yielded a significant reduction in MRSA and VRE CFUs over 15 minutes. Upon exposure to stainless steel plates, CFUs were slowly reduced for 24 hours. In vivo, MRSA CFUs were lower in rooms with copper-containing surfaces compared with controls, both after cleaning and after patients had received visitors (p < 0.05). Analysis of VRE revealed similar results, but VRE CFUs from copper-containing surfaces of drug carts in the ICU did not decrease significantly. @*Conclusions@#Copper has antimicrobial activity and appears to reduce the number of multi-drug resistant microorganisms in a hospital environment. This finding suggests the potential of the use of copper fittings, instruments and surfaces in hospital.

The Experience of RHD Genotyping in D-negative Blood Donors / 대한수혈학회지

Background@#There have been some domestic and overseas cases of anti-D alloimmunization caused by the transfusion of serologically D-negative blood. However, it is difficult to distinguish between true D-negative and DEL variants using conventional serologic typing. Therefore, we established the RHD genotyping algorithm for the detection of DEL variants and applied this algorithm to serologic D negative donors who voluntarily consented to testing. @*Methods@#From September 2016 to December 2020, 216 RHD negative donors who were C＋ and/or E+ in previous serologic typing were recruited. The screening test was PCR amplification of the RHD exons 4, 7, 10, and a promotor. Based on the results of PCR screening, true D-negative samples and RHD variants (including DEL) were discriminated. When the result was a RHD variant, exon 9 was sequenced to identify the nucleotide changes. Full sequencing was performed if no mutations were detected at exon 9. @*Results@#Among the 216 participants, 39 cases with the C−E−c＋e＋ phenotypes that did not meet the recruitment criteria were excluded from data analysis. Among the remaining 177 samples, 68 cases (38.4%) were RHD total deletions, 35 cases (19.8%) were RHD-CE-D hybrids, and 74 cases (41.8%) were RHD variants. Among the cases of RHD variants, 73 cases (98.6%) had c.1227G＞A substitutions and were confirmed as Asian-type DEL. @*Conclusion@#Seventy-four cases of serologic D negative donors were reclassified as RHD variants by RHD genotyping. This is believed to have contributed to the improvement of transfusion safety by lowering the risk of anti-D alloimmunization in D-negative patients.

Highly prevalent BRAF V600E and low-frequency TERT promoter mutations underlie papillary thyroid carcinoma in Koreans

Background@#The presence of telomerase reverse transcriptase (TERT) promoter mutations have been associated with a poor prognosis in patients with papillary thyroid carcinomas (PTC). The frequency of TERT promoter mutations varies widely depending on the population and the nature of the study. @*Methods@#Data were prospectively collected in 724 consecutive patients who underwent thyroidectomy for PTC from 2018 to 2019. Molecular testing for BRAF V600E and TERT promoter mutations was performed in all cases. @*Results@#TERT promoter alterations in two hotspots (C228T and C250T) and C216T were found in 16 (2.2%) and 4 (0.6%) of all PTCs, respectively. The hotspot mutations were significantly associated with older age at diagnosis, larger tumor size, extrathyroidal extension, higher pathologic T category, lateral lymph node metastasis, and higher American Thyroid Association recurrence risk. The patients with C216T variant were younger and had a lower American Thyroid Association recurrence risk than those with hotspot mutations. Concurrent BRAF V600E was found in 19 of 20 cases with TERT promoter mutations. Of 518 microcarcinomas measuring ≤1.0 cm in size, hotspot mutations and C216T variants were detected in five (1.0%) and three (0.6%) cases, respectively. @*Conclusions@#Our study indicates a low frequency of TERT promoter mutations in Korean patients with PTC and supports previous findings that TERT promoter mutations are more common in older patients with unfavorable clinicopathologic features and BRAF V600E. TERT promoter mutations in patients with microcarcinoma are uncommon and may have a limited role in risk stratification. The C216T variant seems to have no clinicopathologic effect on PTC.

Diagnostic usefulness of the cytomegalovirus (CMV)-specific T cell-based assay for predicting CMV infection after kidney transplant

Background/Aims@#We evaluated the usefulness in kidney transplant (KT) candidates of cytomegalovirus (CMV)-specific enzyme-linked immunospot (ELISPOT) assays for predicting the development of post-transplant CMV infections. @*Methods@#All adult recipients admitted for living-donor KT between March 2014 and March 2015 were prospectively enrolled except donor CMV-seropositive and recipient seronegative (D+/R–) recipients. All the enrolled patients underwent CMV-specific ELISPOT assays before transplant, and a researcher blinded to the results of these assays examined the patients for CMV infection at least 6 months post-transplant. @*Results@#Of 133 KT recipients, 44 (33%) developed CMV infections. When we used the cut-off determined by receiver operator characteristic curve, 16 of the 34 patients (47%) with negative pp65-specific ELISPOT results (< 11 spots/200,000 cells) developed CMV infections, whereas 28 of the 99 patients (39%) with positive pp65-specific ELISPOT results at baseline (≥ 11 spots/200,000 cells) developed CMV infections after KT (p = 0.02). Based on the multivariable Cox regression model, negative pp65-specific ELISPOT assay results was an independent risk factor for CMV infection (adjusted hazard ratio [AHR], 1.87; 95% confidence interval [CI], 1.01 to 3.46; p = 0.047) as well as age (AHR, 1.05; 95% CI, 1.01 to 1.08; p = 0.007). @*Conclusions@#Pre-transplant CMV-specific ELISPOT assay appears to predict the development of CMV infections after KT in recipients at moderate risk such as CMV-seropositive recipients (Clinical Trial Registration Number NCT 02025335).

Comparison of the Commercial QuantiFERON-CMV and Overlapping Peptide-based ELISPOT Assays for Predicting CMV Infection in Kidney Transplant Recipients

Cytomegalovirus (CMV) is one of the most important opportunistic infections in transplant recipients. Tests for CMV-specific T cell responses have been proposed to change the current risk stratification strategy using CMV assays. We evaluated the usefulness of pre-transplant CMV-specific T cell assays in kidney transplant (KT) candidates for predicting the development of CMV infection after transplantation comparing the results of the overlapping peptides (OLPs)-based enzyme-linked immunospot (ELISPOT) assay and the commercial QuantiFERON-CMV assay. We prospectively enrolled all cases of KT over a 5-month period, except donor CMV-seropositive and recipient seronegative transplants that are at highest risk of CMV infection. All the patients underwent QuantiFERON-CMV, CMV OLPs-based pp65, and immediate-early 1 (IE-1)-specific ELISPOT assays before transplantation. The primary outcome was the incidence of CMV infection at 6 months after transplant. The total of 47 KT recipients consisted of 45 living-donor KTs and 2 deceased-donor KTs. There was no association between positive QuantiFERON-CMV results and CMV infection. However, 10 of 34 patients with phosphoprotein 65 (pp65)- or IE-1-specific ELISPOT results higher than cut-off value developed CMV infections compared with none of 13 patients with results lower than cut-off value developed CMV. The OLPs-based ELISPOT assays are more useful than the QuantiFERON-CMV assay for predicting CMV infection. Patients with higher CMV-specific T cell immunity at baseline appear to be more likely to develop CMV infections after KT, suggesting that the abrupt decline in CMV-specific T cell responses after immunosuppression, or high CMV-specific T cell responses due to frequent CMV activation before KT, may promote CMV infection.

Tuberculous Meningitis-Mimicking Varicella-Zoster Meningitis / 감염과화학요법

BACKGROUND: Varicella-zoster virus (VZV) is one of the most common etiologies of aseptic meningitis. The severest manifestation of VZV meningitis is occasionally confused with tuberculous meningitis (TBM). Thus, we investigated the clinical manifestations of VZV meningitis as compared with those of TBM. MATERIALS AND METHODS: All adult patients who were diagnosed with VZV meningitis or TBM were enrolled at a tertiary hospital in Seoul, South Korea, during an 8-year period. The clinical characteristics and cerebrospinal fluid (CSF) profile of patients were analyzed. RESULTS: Seventy-nine patients with VZV meningitis and 24 patients with TBM were enrolled in this study. Of the 79 patients with VZV meningitis, 63 (80%) did not received empirical anti-tuberculous therapy (Group 1) and the remaining 16 (20%) received empirical anti-tuberculous therapy (Group 2), compared with 24 patients with TBM (Group 3). Altered mental status, intensive care unit (ICU) admission, neurologic sequelae, CSF protein levels, and CSF adenosine deaminase levels revealed a trend of being higher in Group 3 than Group 2, which was higher than Group 1. However, the CSF/serum glucose ratio was significantly lower in Group 3 than in Group 1 or Group 2. CONCLUSION: About one fifth of VZV meningitis cases presented as severe manifestations, mimicking TBM. The CSF/serum glucose ratio might be useful to differentiate VZV meningitis from TBM until definite diagnostic tests are available. Physicians should keep in mind that a differential diagnosis between severe VZV meningitis and TBM is needed.

Sensitivity of the Cytomegalovirus Antigenemia Assay to Diagnose Cytomegalovirus Retinitis / 감염과화학요법

BACKGROUND: Cytomegalovirus (CMV) retinitis is one of the most important tissue-invasive CMV diseases in immunocompromised patients. Since 1980, non-invasive diagnostic methods, notably the CMV antigenemia assay, have been widely used as adjunct tests to diagnose tissue-invasive CMV diseases. However, there are limited data on the diagnostic value of the CMV antigenemia assay for diagnosing CMV retinitis. MATERIALS AND METHODS: We performed a retrospective review of all cases of CMV retinitis at Asan Medical Center, Seoul, South Korea over a 9-year period. The diagnosis of CMV retinitis was made by experienced ophthalmologists according to medical history and an ophthalmoscopic appearance of typical retinopathy, together with absence of an alternative diagnosis. RESULTS: We analyzed 44 patients with CMV retinitis (affecting 57 eyes) for whom the CMV antigenemia assay was performed. Of the 44 patients, 31 (70%) were HIV-uninfected and 13 (30%) were HIV-infected. The overall sensitivity of the CMV antigenemia assay was 66% (95% confidence interval [CI] 50–80%). The test’s sensitivity showed a non-significant trend towards being higher in HIV-infected patients than in HIV-uninfected patients (sensitivity 85% vs 58%, respectively, P = 0.16). In a subgroup analysis of the 35 patients without other concurrent tissue-invasive CMV disease, the sensitivity of the CMV antigenemia assay was 57% (95% CI 40–74%). CONCLUSIONS: The CMV antigenemia assay has limited value as a non-invasive diagnostic adjunct test for CMV retinitis. Therefore, the results of the assay need to be interpreted in the context of underlying disease, clinical presentation, and ophthalmoscopic findings.

Heart transplantation in a patient with eosinophilic granulomatosis with polyangiitis known as Churg-Strauss syndrome

Eosinophilic granulomatosis with polyangiitis (EGPA), also known as Churg-Strauss syndrome, is a rare systemic necrotizing vasculitis affecting small- to medium-sized vessels. EGPA is associated with severe asthma and eosinophilia. The most frequently involved organs are skin and peripheral nerves; however, EGPA may involve other organs, such as the gastrointestinal tract, kidney, and heart. Antineutrophil cytoplasm antibodies (ANCAs)-related abnormal immune reactions are known to be associated with EGPA, but only 30%-40% of patients have a positive marker of ANCA. ANCA-negative patients are at higher risk of cardiac involvement than ANCA-positive patients. Cardiac involvement is one of the leading causes of mortality and could be resistant to conventional treatment. Early treatment with steroid plus cyclophosphamide is important because it could give chances of restoration of cardiac function. For patients undergoing heart transplantation, we should consider the severity of cardiac disease and the presence of systemic diseases, including vasculitis. Here, we report a case of a 25-year-old EGPA patient with cardiac involvement who eventually received heart transplantation for progressive heart failure, although treated with systemic corticosteroid with cyclophosphamide. EGPA patients undergoing heart transplantion are rarely reported worldwide, and this is the first case report in Korea.

Pyogenic Sacroiliitis Caused by Salmonella enterica Serotype Livingstone / 대한내과학회지

Pyogenic sacroiliitis is a rare joint infection, with a challenging diagnosis due to its nonspecific indicators and symptoms. Staphylococcus aureus is the most common causative bacteria of pyogenic sacroiliitis, with Pseudomonas aeruginosa being the most common causative gram-negative bacteria. Interestingly, whereas Salmonella species. is reportedly the second most common cause of this disorder there have been no reported cases of acute sacroiliitis due to Salmonella spp. in Korea, to the best of our knowledge. In this study, we report on the first case in a young Korean adult caused by Salmonella enterica serotype Livingstone, with no underlying disease or predisposing factors.

Use of Splenectomy to Treat Evans Syndrome Following an ABO-Matched Liver Transplant / 대한내과학회지

Evans syndrome is a rare complication that develops in adults after liver transplantation. The possible etiologies include ABO mismatch, viral infection, post-transplantation lymphoproliferative disease, graft-versus-host disease, and the use of certain immunosuppressive drugs (e.g., calcineurin inhibitors). Here, we present a case of Evans syndrome that developed after an ABO-matched liver transplant. Glucocorticosteroid, intravenous immunoglobulin, and alternative immunosuppressant therapies all failed. Weekly rituximab (375 mg/m2) was then administered for 4 weeks. The cytopenia improved transiently after the second dose of rituximab, but soon worsened again. However, the cytopenia normalized after a splenectomy.

A Case of Vertebral Osteomyelitis with Bacteremia and Psoas Abscess Caused by Non-typeable Haemophilus influenzae / 대한내과학회지

Vertebral osteomyelitis is primarily seen in middle-aged individuals, with a mean age of presentation of ~60 years. Recent trends suggest an increase in the incidence of vertebral osteomyelitis due to longer life expectancy of patients with chronic debilitating diseases. Haemophilus influenzae is a small, fastidious, gram-negative bacillus, which is known to cause infections in young children. While invasive H. influenzae infections have become increasingly common in adult populations, bone infections caused by this organism remain extremely rare. The existing medical literature includes only 11 reports of vertebral osteomyelitis caused by H. influenzae since 1978, with no reports of H. influenzae-associated vertebral osteomyelitis observed in Korea. Here, we present the case of a 72-year old patient with hematogenous vertebral osteomyelitis and psoas abscess caused by non-typeable H. influenzae.

A Case of Vertebral Osteomyelitis with Bacteremia and Psoas Abscess Caused by Non-typeable Haemophilus influenzae / 대한내과학회지

Vertebral osteomyelitis is primarily seen in middle-aged individuals, with a mean age of presentation of ~60 years. Recent trends suggest an increase in the incidence of vertebral osteomyelitis due to longer life expectancy of patients with chronic debilitating diseases. Haemophilus influenzae is a small, fastidious, gram-negative bacillus, which is known to cause infections in young children. While invasive H. influenzae infections have become increasingly common in adult populations, bone infections caused by this organism remain extremely rare. The existing medical literature includes only 11 reports of vertebral osteomyelitis caused by H. influenzae since 1978, with no reports of H. influenzae-associated vertebral osteomyelitis observed in Korea. Here, we present the case of a 72-year old patient with hematogenous vertebral osteomyelitis and psoas abscess caused by non-typeable H. influenzae.

Peripheral Primitive Neuroectodermal Tumor with Osseous Component of the Small Bowel Mesentery: A Case Study

A case of peripheral primitive neuroectodermal tumor of the small bowel mesentery with osseous component is reported. A 23-year-old man was admitted to our hospital because of acute severe abdominal pain. Abdominal computed tomography revealed a large solid and cystic, oval shaped mass, measuring 11.0x6.0 cm in the pelvic cavity. Histologically the resected lesion consisted of sheets of undifferentiated small round cells forming Homer-Wright rosettes and perivascular pseudorosettes, and showed areas of osteoid and bone formation. Immunohistochemical studies revealed that tumor cells expressed positivity against CD99 (MIC2), CD57, neuron-specific enolase, and vimentin. Fluorescence in situ hybridization study revealed Ewing sarcoma breakpoint region 1 (EWSR1) gene rearrangement on chromosome 22q12. To the authors' knowledge this is the first documentation of a peripheral neuroectodermal tumor with osteoid and bone formation of the small bowel mesentery.

Ultrasonographic findings of pylorogastric intussusceptions in two dogs

A Yorkshire terrier (case 1) and a Miniature Schnauzer (case 2) were diagnosed with pylorogastric intussusceptions (PGIs). Both cases showed acute vomiting and had previous histories of laparotomy. In case 1, the invaginated pyloric wall was thickened unevenly containing multiple hypoechoic areas and had indistinct wall layering on ultrasonography. PGI with diffuse gastric edema and necrosis was confirmed on laparotomy. The dog recovered completely after gastrectomy and a Y-U plasty. Case 2 had uniformly thickened walls of invaginated gastric pylorus with the distinct wall layering. PGI was reduced spontaneously the next day.

Laparoscopically Resected Composite Pheochromocytoma-Ganglioneuroma

Composite pheochromocytoma-ganglioneuroma is one of the mixed neuroendocrine-neural tumors composed of pheochromocytoma and other neural crest derivatives. To date, less than 50 cases of composite pheochromocytoma have been reported, and about 70% of the accompanying tumors were ganglioneuromas. Here, we describe six cases of composite pheochromocytoma-ganglioneuromas in five men and one woman, aged 33 to 64. The size of the tumors ranged from 3.0 to 11.0 cm, and four out of the six presented with intermittent onset of hypertension, palpitation, or dizziness. Microscopically, each tumor was composed of large pleomorphic shaped chromaffin cells arranged in the Zellballen patterns characteristic of pheochromocytoma, and they were mixed with clusters of mature ganglion cells and bundles of spindle-shaped Schwann cells characteristic of ganglioneuroma of variable proportions. All were successfully treated laparoscopically, and none were associated with multiple endocrine neoplasm syndrome or neurofibromatosis. Preoperative diagnosis of a composite pheochromocytoma-ganglioneuroma is impossible because of the low incidence rate, and the radiological findings and symptoms are similar to those of typical pheochromocytomas. Although the significance of microscopic detection of the nonpheochromocytoma component from pheochromocytoma has not yet been clarified, microscopic identification of the composite pheochromocytoma-ganglioneuroma is important because cumulative cases are used in an effort to predict the behavior of this composite tumor.

Value of Bronchoalveolar Lavage Fluid Cytology in the Diagnosis of Pneumocystis jirovecii Pneumonia: A Review of 30 Cases / 결핵및호흡기질환

BACKGROUND: Pneumocystis jirovecii is a fungus that has become an important cause of opportunistic infections. We present a summary of the clinical status and findings from bronchoalveolar lavage (BAL) of patients with Pneumocystis jirovecii pneumonia (PJP). METHODS: We selected 30 cases of PJP that were proven through a surgical specimen evaluation. BAL fluid cytology was reviewed, and agreement with the initial diagnosis was evaluated. RESULTS: All 30 cases of PJP occurred in immunocompromised patients. Only 15 of the 30 cases were initially diagnosed as PJP. We found PJP in 13 of the 15 cases that were negative at the initial diagnosis. The most characteristic finding of PJP was frothy exudates, and BAL fluid tended to show rare neutrophils. Two of seven patients with PJP and diffuse alveolar damage (DAD) revealed no frothy exudates in BAL fluid. CONCLUSION: BAL fluid cytology was reconfirmed as a sensitive and rapid method to diagnose PJP. We must be aware of the possibility of PJP to maintain high diagnostic sensitivity. We cannot exclude PJP in cases of PJP with DAD, even if frothy exudates are not observed in the BAL fluid.

Primary Acinic Cell Carcinoma of the Lung: A Case Report

Primary acinic cell carcinoma (ACC) of the lung is very rare and this tumor is thought to arise from pluripotent cells of the submucosal glands of the tracheobronchial tree. We report here on a case of primary ACC of the lung in a 68-year-old man who had a solitary pulmonary nodule in the left lower lobe. The patient was symptomless and the lesion was found on a chest X-ray taken during a regular health checkup. The video assisted thoracoscopic surgery wedge resection revealed an ovoid yellow tan solid mass that was 1.8 cm at the largest diameter. Microscopically, the neoplastic cells grew in solid sheets of round cells with eccentric nuclei and abundant basophilic granular cytoplasm. There were no mitotic figures or areas of pleomorphic or anaplastic cells. Immunohistochemical staining for cytokeratin (AE1/AE3) was positive, but the staining for chromogranin A and CD56 was negative. Ultrastructural examination revealed polyhedral cells with many zymogen granules of varying electron density. The patient is well 4 months postoperatively.

Comparative Study of Metaplastic Breast Carcinoma and Triple-Negative Breast Carcinoma Using Histologic and Immunohistochemical Analyses

BACKGROUND: Metaplastic carcinoma of the breast is a rare subtype of breast cancer, which is characterized by estrogen receptor/progesterone receptor and HER2 negativity. METHODS: Tissue specimens from 60 metaplastic breast cancer and 60 triple-negative breast cancer patients diagnosed at a single institution between 1995 and 2009 were analyzed. Immunohistochemistry for caveolin-1 (CAV-1), vascular endothelial growth factor (VEGF), epidermal growth factor receptor (EGFR), c-kit, p53, Ki-67, breast cancer type 1 susceptibility protein (BRCA1), cytokeratin (CK)14, and CK17 were performed on both retained tissue sets. RESULTS: Of the 60 metaplastic carcinomas, 15 tumors (25%) exhibited spindle cell component, 27 (45%) exhibited chondroid differentiation, and 18 (30%) exhibited squamous areas. Compared to triple-negative carcinomas, metaplastic carcinomas significantly more frequently expressed CK14 (p < 0.0001), CK17 (p = 0.002), EGFR (p < 0.0001), CAV-1 (p < 0.0001), and VEGF (p = 0.029). However, expressions of BRCA1, p53, c-kit, and Ki-67 were not significantly different between both groups. CONCLUSIONS: The expression profile of metaplastic carcinoma of the breast is more homogeneous than that of other triple-negative tumors and frequently over-expresses basal markers, CAV-1, and VEGF. A typical "basal-like" phenotype and frequent expressions of CAV-1 and VEGF may justify specific therapeutic approaches.