Mucoepidermoid carcinoma of the lung: a case report and literature review.

Introduction. Mucoepidermoid carcinoma (MEC) of the lung is a rare form of lung cancer that is classified into low grade and high grade based on histological features. Surgical resection is the primary treatment for low-grade MEC with excellent outcomes, while high-grade MEC is a more aggressive form of malignancy. Clinical Case. We report a case of a 46-year-old woman who presented with dyspnea on exertion. Imaging studies revealed a mass involving the right upper lobe bronchus. Bronchoscopy, surgical resection, and pathological examination revealed a low-grade MEC with tumor-free margins. No adjuvant treatment was given. Discussion. Primary pulmonary MEC is a rare type of lung cancer with only few reported cases. This patient illustrates a typical presentation for low-grade MEC wherein surgical resection is considered curative. In contrast, high-grade MEC is a more aggressive malignancy with a poorer outcome. The role of targeted therapy directed against EGFR or a novel CRTC1-MAML2 fusion protein expressed in some high-grade tumors is yet to be determined.

Robotic Heller myotomy: a safe operation with higher postoperative quality-of-life indices.

INTRODUCTION: Achalasia is a primary motility disorder of the esophagus that is treated most effectively with operative myotomy. Excellent outcomes with laparoscopic myotomy and fundoplication are well known. Heller myotomy utilizing a computer-enhanced (robotic) laparoscopic platform allows for a more precise dissection by utilizing the superior optics of a 3-dimensional camera and greater degrees of freedom provided by robotic instrumentation. How this affects outcome and quality of life is unknown. METHODS: We assessed patients' health perceptions using a standardized, validated, health-related, disease-specific quality-of-life metric. Sixty-one consecutive patients undergoing laparoscopic or robotic myotomy over a 6-year period were evaluated prospectively. All operations were performed using intraoperative manometric and endoscopic guidance and all except 5 patients had a fundoplication. The effects of the operation on health-related quality of life were evaluated with the Short Form (SF-36) Health Status Questionnaire and a disease-specific gastroesophageal reflux disease activity (GERD) activity index (GRACI) preoperatively and postoperatively. All patients completed the questionnaire at both time points. Patient scores were compared using 2-way repeated measures analyses of variance followed by the Tukey test. Operative time, estimated blood loss, duration of stay, intraoperative complication, and postoperative complications were analyzed. RESULTS: Thirty-seven patients had laparoscopic and 24 patients had robotic Heller myotomy. There was an increase in SF-36 overall evaluation of health postoperatively compared with preoperatively in both groups (P < .05). The robotic myotomy patients had better SF-36 Role Functioning (emotional) and General Health Perceptions (P < .05) compared with the laparoscopic group. The GRACI showed an equivalent improvement in severity of symptoms in both groups (P < .05). Operative time was 287 +/- 9 minutes for laparoscopic cases and 355 +/- 23 minutes for robotic cases. Estimated blood loss and duration of stay were not different between groups. There were 3 operative esophageal perforations (8%) during laparoscopic myotomy and all were repaired immediately. There were no perforations or operative complications in the robotic group. Neither group had any additional complications. CONCLUSIONS: Minimally invasive operative myotomy improves functional status and overall evaluation of health in patients with achalasia. Robotic myotomy had no intraoperative esophageal perforations compared with an 8% intraoperative rate during laparoscopic myotomy. Heller myotomy with partial fundoplication using a robotic platform appears to be a more precise and safer operation than laparoscopic myotomy with improved quality-of-life indices postoperatively compared with laparoscopic myotomy with fewer complications; this suggests that, in skilled hands, the robotic platform may be safer, with improved quality-of-life outcomes.

Angiogenic proteins in the lungs of children after cavopulmonary anastomosis.

OBJECTIVE: Pulmonary arteriovenous malformations may cause progressive cyanosis after cavopulmonary anastomosis and may develop as a result of abnormal angiogenesis. We used immunohistochemistry to determine whether angiogenic proteins are increased in the lungs of children after cavopulmonary anastomosis. METHODS: Lung specimens were obtained from 13 children after cavopulmonary anastomosis and from 6 control subjects. Specimens were stained with antibodies against vascular endothelial growth factor and its receptor (flk-1/KDR), basic fibroblast growth factor, alpha-smooth muscle actin, CD31, collagen IV, fibronectin, and proliferating cell nuclear antigen. Staining was graded on a scale of 0 to 3. Vessels positive for proliferating cell nuclear antigen were counted in 10 fields per specimen, and the results were averaged. RESULTS: After cavopulmonary anastomosis, patients demonstrated increased staining for vascular endothelial growth factor (P =.03) and its receptor (P =.03) and decreased staining for CD31 (P =.004). Proliferating cell nuclear antigen staining in patients was equivalent to that for control subjects (P =.9). CONCLUSIONS: Lung biopsy specimens from children after cavopulmonary anastomosis demonstrate increased expression of vascular endothelial growth factor and its receptor. These data confirm earlier findings that blood vessels forming after cavopulmonary anastomosis may have reduced intercellular junctions (decreased CD31 staining). Despite the increased numbers of pulmonary vessels that are present in these patients, these vessels are not highly proliferative (proliferating cell nuclear antigen staining equivalent to that of control subjects). These results suggest that vascular endothelial growth factor may be a mediator of angiogenesis in the lungs of children after cavopulmonary anastomosis; however, other factors, such as vascular dilation and remodeling, may also be important.

Pulmonary microvessel density is a marker of angiogenesis in children after cavopulmonary anastomosis.

OBJECTIVE: Pulmonary arteriovenous malformations cause progressive cyanosis in children after cavopulmonary anastomosis and may be due to abnormal angiogenesis. We determined the microvessel density, a marker of angiogenesis, in the lungs of children after cavopulmonary anastomosis. METHODS: Lung biopsy specimens were obtained from 8 children after cavopulmonary anastomosis and from 4 control patients. Three of the 8 children undergoing cavopulmonary anastomosis had clinical and angiographic evidence of pulmonary arteriovenous malformations, whereas the other 5 were free of symptoms. Routine histologic and immunohistologic stains were performed with a primary antibody to von Willebrand factor. Microvessel staining for von Willebrand factor was determined for 10 fields (200x) per patient. RESULTS: Patients with and without pulmonary arteriovenous malformations after cavopulmonary anastomosis demonstrated significantly increased microvessel density compared with control subjects (32.7 +/- 2.8 vs 9.3 +/- 4.6, P =.02, and 31.5 +/- 15.7 vs 9.3 +/- 4.6, P =.01, respectively). There was no difference in microvessel density in children with and without clinically apparent pulmonary arteriovenous malformations after cavopulmonary anastomosis (P =.9). The children with pulmonary arteriovenous malformations had numerous greatly dilated vessels that were absent in the asymptomatic children after cavopulmonary anastomosis. CONCLUSIONS: After cavopulmonary anastomosis, pulmonary microvessel density is increased even in the absence of clinically apparent pulmonary arteriovenous malformations, supporting the presence of a constant angiogenic stimulus. Children with clinically apparent pulmonary arteriovenous malformations possess large numbers of greatly dilated pulmonary microvessels, which are absent in asymptomatic children after cavopulmonary anastomosis. These results suggest that the transition to clinically apparent pulmonary arteriovenous malformations may be due to mechanisms that lead to vessel dilation and remodeling.

Vascular endothelial growth factor and basic fibroblast growth factor in children with cyanotic congenital heart disease.

OBJECTIVE: Vascular endothelial growth factor and basic fibroblast growth factor are potent stimulators of angiogenesis. Children with cyanotic congenital heart disease often experience the development of widespread formation of collateral blood vessels, which may represent a form of abnormal angiogenesis. We undertook the present study to determine whether children with cyanotic congenital heart disease have elevated serum levels of vascular endothelial growth factor and basic fibroblast growth factor. METHODS: Serum was obtained from 22 children with cyanotic congenital heart disease and 19 children with acyanotic heart disease during cardiac catheterization. Samples were taken from the superior vena cava, inferior vena cava, and a systemic artery. Vascular endothelial growth factor and basic fibroblast growth factor levels were measured in the serum from each of these sites by enzyme-linked immunosorbent assay. RESULTS: Vascular endothelial growth factor was significantly elevated in the superior vena cava (P =.04) and systemic artery (P =.02) but not in the inferior vena cava (P =.2) of children with cyanotic congenital heart disease compared to children with acyanotic heart disease. The mean vascular endothelial growth factor level, determined by averaging the means of all 3 sites, was also significantly elevated (P =.03). Basic fibroblast growth factor was only significantly elevated in the systemic artery (P =.02). CONCLUSION: Children with cyanotic congenital heart disease have elevated systemic levels of vascular endothelial growth factor. These findings suggest that the widespread formation of collateral vessels in these children may be mediated by vascular endothelial growth factor.

A detailed histologic analysis of pulmonary arteriovenous malformations in children with cyanotic congenital heart disease.

INTRODUCTION: Pulmonary arteriovenous malformations are a common cause of progressive cyanosis in children after cavopulmonary anastomoses. We analyzed the pulmonary histologic characteristics from children in whom pulmonary arteriovenous malformations developed after procedures that resulted in pulmonary arterial blood flow devoid of hepatic venous effluent. METHODS: We performed routine histologic studies, immunohistochemical staining, and electron microscopic analysis of peripheral lung biopsy specimens from 2 children with angiographically proven pulmonary arteriovenous malformations. Microvessel density was determined with a computer-assisted, morphometric analysis system. RESULTS: Histologic examination demonstrated large, dilated blood vessels ("lakes") and clustered, smaller vessels ("chains") in the pulmonary parenchyma. Microvessel density was significantly greater in these patients than in age-matched controls (P =.01). Immunohistochemistry demonstrated uniform staining for type IV collagen and alpha-smooth muscle actin, weak staining for the endothelial marker CD31 (cluster of differentiation, PECAM-1), and negative staining for proliferating cell nuclear antigen. Electron microscopy revealed endothelial irregularity, a disorganized basement membrane, and increased numbers of collagen and actin filaments beneath the endothelium. CONCLUSIONS: This study represents an attempt to characterize the histologic features of pulmonary arteriovenous malformations in children with congenital heart disease who have pulmonary arterial blood flow devoid of hepatic venous effluent. The histologic correlate of this condition appears to be greatly increased numbers of thin-walled vessels. Immunohistochemistry suggests that the rate of cellular proliferation is not increased in these lesions. The development of these techniques may provide a standardized histologic approach for this condition and aid in understanding its etiology.

Noninvasive evaluation of hand circulation before radial artery harvest for coronary artery bypass grafting.

OBJECTIVE: Radial artery harvesting for coronary artery bypass may lead to digit ischemia if collateral hand circulation is inadequate. The modified Allen's test is the most common preoperative screening test used. Unfortunately, this test has high false-positive and false-negative rates. The purpose of this study was to compare the results of a modified Allen's test with digit pressure change during radial artery compression for assessing collateral circulation before radial artery harvest. METHODS: One hundred twenty-nine consecutive patients were studied before coronary artery bypass operations. A modified Allen's test was performed with Doppler ultrasound to assess blood flow in the superficial palmar arch before and during radial artery compression. A decreased audible Doppler signal after radial artery compression was considered a positive modified Allen's test. First and second digit pressures were measured before and during radial artery compression. A decrease in digit pressure of 40 mm Hg or more (digit DeltaP) with radial artery compression was considered positive. RESULTS: Seven of 14 dominant extremities (50%) and 8 of the 16 nondominant extremities (50%) with a positive modified Allen's test had a digit DeltaP of less than 40 mm Hg (false positive). Sixteen of 115 dominant extremities (14%) and 5 of 112 nondominant extremities (4%) with a negative Allen's test had a digit DeltaP of 40 mm Hg or more with radial artery compression (false negative). CONCLUSION: Use of the modified Allen's test for screening before radial artery harvest may unnecessarily exclude some patients from use of this conduit and may also place a number of patients at risk for digit ischemia from such harvest. Direct digit pressure measurement is a simple, objective method that may more precisely select patients for radial artery harvest. Additional studies are needed to define objective digital pressure criteria that will accurately predict patients at risk for hand ischemia after radial harvest.