Salivary acinic cell carcinoma: reappraisal and update.

Epidemiologic and clinicopathologic features, therapeutic strategies, and prognosis for acinic cell carcinoma of the major and minor salivary glands are critically reviewed. We explore histopathologic, histochemical, electron microscopic and immunohistochemical aspects and discuss histologic grading, histogenesis, animal models, and genetic events. In the context of possible diagnostic difficulties, the relationship to mammary analog secretory carcinoma is probed and a classification is suggested. Areas of controversy or uncertainty, which may benefit from further investigations, are also highlighted.

Replication of HIV-1 in dendritic cell-derived syncytia at the mucosal surface of the adenoid.

Human immunodeficiency virus-type 1 (HIV-1) replicates actively in infected individuals, yet cells with intracellular depots of viral protein are observed only infrequently. Many cells expressing the HIV-1 Gag protein were detected at the surface of the nasopharyngeal tonsil or adenoid. This infected mucosal surface contained T cells and dendritic cells, two cell types that together support HIV-1 replication in culture. The infected cells were multinucleated syncytia and expressed the S100 and p55 dendritic cell markers. Eleven of the 13 specimens analyzed were from donors who did not have symptoms of acquired immunodeficiency syndrome (AIDS). The interaction of dendritic cells and T cells in mucosa may support HIV-1 replication, even in subclinical stages of infection.

Spoilage and safety characteristics of ground beef treated with lactic acid bacteria.

Lactic acid bacteria (LAB) can decrease numbers of Escherichia coli O157:H7 and Salmonella in ground beef during storage. Two dose-titration studies were conducted in ground beef to determine dose levels of LAB needed to inhibit the pathogens. A second study evaluated whether LAB masked changes typically associated with the spoilage of ground beef displayed under refrigerated (0 degrees C) or abusive (10 degrees C) temperatures packaged in both traditional overwrap (TOP) and modified atmosphere packaging (MAP; 80% O(2)-20% CO(2)). Microbial analyses were conducted to determine spoilage endpoints and pathogen reduction. In the dose-titration study, Salmonella was reduced by 3 log cycles at all doses (10(6), 10(7), and 10(8) LAB per g) after 3 days of storage and was eliminated after 5 days of storage. E. coli O157:H7 was reduced by 2 log cycles at all dosages after 3 days of storage and by 3 log cycles after 5 days of storage. In the spoilage studies, as expected, total aerobic plate counts and LAB populations in LAB-inoculated samples were higher than the controls initially, but the counts were similar near the end of the study. While total spoilage bacteria generally increased over time, very few differences existed between treatments stored at 0 degrees C and 10 degrees C in coliforms, Brochothrix thermosphacta, yeasts and molds, and Pseudomonas spp. counts for both the TOP and MAP samples. We conclude that LAB could potentially be added to ground beef in TOP and MAP as a processing intervention for E. coli O157:H7 and Salmonella without masking microbial spoilage characteristics.

Control of Listeria monocytogenes in turkey deli loaves using organic acids as formulation ingredients.

The growth of Listeria monocytogenes in further-processed meat products has become a major concern and an important food safety issue. The meat and poultry industries have incorporated interventions such as organic acids in marinades to inhibit the growth of L. monocytogenes. In this study, organic acids were utilized in the raw product and as a postcook dip to determine their inhibitory effect on the growth of L. monocytogenes in turkey deli loaves. The turkey deli loaves were processed, cooked, cooled, inoculated with streptomycin-resistant L. monocytogenes, and then dipped. Treatments were potassium lactate (PL) in the raw product with sodium lactate (SL), sodium diacetate (SD) dip, PL with SL/PL/SD dip, SL with SL/SD dip, and SL with SL/PL/SD dip. There was also a positive (inoculated) and negative (noninoculated) control, which was dipped in distilled water. Days 0, 7, 14, 21, 28, 42, and 56 were sampled for L. monocytogenes. There were no differences (P>0.05) among the organic acid treatments in the turkey deli loaves at any time points; therefore, all of the treatments increased the lag phase of L. monocytogenes, extending the shelf-life of the product. However, there was a difference between the treatments and the positive control at d 7, 14, 21, 28, 42, and 56. The growth of L. monocytogenes increased immediately in the positive control, whereas the negative control appeared to have no growth. These organic acids can provide meat processors with a useful method for extending the lag phase of L. monocytogenes in ready-to-eat meat and poultry products.

Comparison of quality attributes of shell eggs subjected to directional microwave technology.

Microwaves have been shown to cause thermal as well as nonthermal destruction of pathogens such as Salmonella, which can be found in shell eggs. The objective of this study was to determine if using microwave technology would cause detrimental quality effects in shell eggs. Treatments included control (no treatment) and microwave-treated (20 s) shell eggs. There were no differences in mineral content, fatty acid profile, Haugh units, broken-out score, yolk index, emulsion stability, pH of whole egg, and foaming capacity between 2 treatments (P >or= 0.05). At 0 and 30 d, there were no noticeable differences in H(2)O activity between 2 treatments. The foaming stability and albumen thermocoagulation of microwave-treated eggs were significantly higher than control eggs (P or= 0.05). Therefore, microwave technology can be applied to shell eggs without causing detrimental effects to quality.

Reduction of Salmonella Enteritidis in shell eggs using directional microwave technology.

Microwaves have been shown to cause thermal as well as nonthermal destruction of pathogens such as Salmonella Enteritidis, which is commonly found in shell eggs. The objective of this study was to examine the use of new directional microwave technology to reduce Salmonella Enteritidis without causing any detrimental effects on quality in white and brown eggs. Treatments were control and microwaved white and brown eggs. Applying directional microwave technology resulted in a 2-log reduction of Salmonella Enteritidis in both the high (10(5) cfu/g) and low (10(2) cfu/g) inoculum. At d 0, there were no differences in water activities, albumen pH, and combined pH between treatments; however, there were significant changes in yolk pH. Collectively, these results indicate that applying directional microwave technology can reduce Salmonella Enteritidis in shell eggs without causing any detrimental effects to quality.

Marination of turkey breast fillets to control the growth of Listeria monocytogenes and improve meat quality in deli loaves.

Turkey deli loaves were evaluated using organic marinades in the raw product to control the growth of Listeria monocytogenes (LM) and improve meat quality in the cooked product. Treatments included sodium tripolyphosphate (STP; 0.45%, control), sodium lactate (3%), sodium diacetate (0.25%), sodium citrate (0.75%), and sodium lactate (3%)/sodium diacetate (0.25%) combination, all containing 1.5% salt. Data collected in the 2 trials included pH; lightness, redness, and yellowness; bind ability; cooked meat moisture; oxidation (thiobarbituric acid reactive substances); aerobic plate count (d 0 to 80); and sensory evaluation. Also, thirty-two slices from each loaf were inoculated with a 10(3) cfu/ mL surface inoculum streptomycin-resistant LM cocktail and analyzed for LM levels (d 0 to 77). The sodium lactate treatment was lower in pH (5.84) postmarination. Lactate, citrate, and the combination treatments had significantly lower lightness values; lactate, diacetate, and citrate had higher redness values; and lactate had lower yellowness values postmarination compared with premarination. Cook loss, moisture, and bind ability were higher in the STP treatment. Citrate and the combination treatments had lower thiobarbituric acid reactive substances on d 3, but there were no differences by d 15. Cohesiveness was significantly higher in the STP, lactate, and diacetate treatments, and turkey flavor was more intense in the combination treatment. The STP loaves had >10(6) cfu/cm(2) aerobic plate count by 14 d, lactate by 20 d, citrate by 40 d, diacetate by 70 d, and lactate/diacetate by 74 d. Sodium diacetate, citrate, and lactate/diacetate all extended the lag phase of LM. Therefore, acidic marinades applied in the raw product do have a negative effect on some cooked product quality attributes but do improve shelf life and decrease LM growth by extending the lag phase through 21 d postmortem.

Nutrient composition and retention in whole turkeys with and without added solution.

Whole turkeys sold in retail outlets are typically processed with added solutions to improve their taste and tenderness. The purpose of this study was to evaluate the nutrient composition of whole turkeys with and without added solution, and to update the nutrient profile of turkey for the USDA National Nutrient Database for Standard Reference. Eleven pairs of turkeys with added solution were obtained from statistically representative retail outlets using a nationwide sampling plan developed for USDA's National Food and Nutrient Analysis Program; 4 pairs of turkeys without added solution were purchased from local food outlets. Turkeys were roasted to an internal temperature of 165°F (74°C). Values of selected nutrients in light and dark meat, including skin, were determined by USDA approved laboratories using quality assurance protocols. Both raw and cooked turkeys, with and without added solution, were compared by one-way and 2-way factorial ANOVA. The results showed a significant interaction for fat (P < 0.0001) and zinc (P = 0.0070) between turkeys that were raw and cooked and those prepared with or without added solution. Fat was higher in raw turkeys with added solution compared to without added solution. Similarly, sodium, phosphorus, and calcium values were significantly higher in turkeys with added solution (P < 0.05) than in turkeys without added solution. Data from this study will be useful for developing strategies to address sodium-related health issues, nutrition monitoring, consumption surveys, and policy development.

Is it necessary to routinely fenestrate an extracardiac fontan?

OBJECTIVES: This study was conducted to assess the need for, and use of, fenestration of an extracardiac conduit Fontan. BACKGROUND: Fenestration of a Fontan connection has been proposed as a means of improving outcomes of single ventricle palliation. The benefit of fenestration is likely to be greatest in the early postoperative period when patients may experience increased pulmonary vascular resistance and decreased ventricular function due to the effects of cardiopulmonary bypass, aortic cross-clamping and positive pressure ventilation. However, there are potential drawbacks to fenestration. The utility of fenestration with extracardiac Fontan operation has not been determined. METHODS: Since 1992, 81 patients have undergone a modification of the Fontan procedure in which an extracardiac inferior cavopulmonary conduit is used in combination with a previously staged bidirectional Glenn anastomosis. We conducted a retrospective review of these patients. RESULTS: Fenestration was performed selectively in 32 patients (39%), including only 2 of the last 38 (5%). In seven patients, a fenestration was placed or clipped in the early postoperative period without cardiopulmonary bypass. There were two operative deaths. Prolonged (>2 weeks) pleural drainage occurred in 13 patients, 8 with fenestration and 5 without. In addition to undergoing earlier Fontan in our experience, patients who had a fenestration placed had significantly higher preoperative pulmonary vascular resistance, significantly higher common atrial pressure after Fontan and significantly lower post-Fontan systemic arterial oxygen saturation. Fontan pressure did not differ between nonfenestrated and fenestrated patients. At follow-up ranging to five years, there were two late deaths and no patients developed protein losing enteropathy. CONCLUSIONS: Fenestration is not necessary in most Fontan patients when an extracardiac conduit technique is performed as described in this article, and therefore, should not be performed routinely with the extracardiac conduit Fontan. The need for fenestration should be assessed after cardiopulmonary bypass when hemodynamics can be evaluated accurately. Fenestration can be placed and revised easily without bypass and with minimal intervention in patients with an extracardiac conduit Fontan.

Nutrient database improvement project: Separable components and proximate composition of raw and cooked retail cuts from the beef loin and round.

Beef nutrition research has become increasingly important domestically and internationally for the beef industry and its consumers. The objective of this study was to analyze the nutrient composition of ten beef loin and round cuts to update the nutrient data in the USDA National Nutrient Database for Standard Reference. Seventy-two carcasses representing a national composite of Yield Grade, Quality Grade, sex classification, and genetic type were identified from six regions across the U.S. Beef short loins, strip loins, tenderloins, inside rounds, and eye of rounds (NAMP # 173, 175, 190A, 169A, and 171C) were collected from the selected carcasses and shipped to three university meat laboratories for storage, retail fabrication, and raw/cooked analysis of nutrients. Sample homogenates from each animal were analyzed for proximate composition. These data provide updated information regarding the nutrient status of beef, in addition, to determining the influence of Quality Grade, Yield Grade, and sex classification on nutrient composition.

Construction and expression of a synthetic streptavidin-encoding gene in Escherichia coli.

A synthetic gene encoding 'core' streptavidin (SAV) [amino acid (aa) residues 13-140 of Streptomyces avidinii SAV] has been efficiently expressed in Escherichia coli from the IPTG-inducible lac promoter of plasmid pET3a. In this system, expression levels are nearly tenfold greater for the synthetic gene than for the corresponding native gene. The synthetic gene was constructed from overlapping oligodeoxyribonucleotides whose sequences were optimized to incorporate codons preferred by highly expressed E. coli genes. Biochemical characterizations by gel methods, aa analysis, N-terminal sequencing, and size exclusion chromatography show that the synthetic gene product purified by affinity chromatography possesses the properties expected for core SAV.

Fusion of pro region of subtilisin to staphylococcal protein A and its secretion by Bacillus subtilis.

Subtilisin is synthesized as a preproenzyme in Bacillus subtilis. We fused that region of the subtilisin gene, (apr[BamP]), which encodes the signal sequence and pro region, to the mature gene sequence (spa) for a heterologous protein (staphylococcal protein A). B. subtilis cells harboring this gene fusion synthesized a fusion protein consisting of the signal and pro sequence of subtilisin fused to the protein A; the signal sequence was processed and a fusion protein (pro + protein A) was secreted into the growth medium.

Extracranial sinonasal tract meningiomas: a clinicopathologic study of 30 cases with a review of the literature.

Extracranial meningiomas of the sinonasal tract are rare tumors. These tumors are frequently misclassified, resulting in inappropriate clinical management. To date, there has been no comprehensive study to evaluate the clinicopathologic aspects of meningioma in these anatomic sites. Thirty cases of sinonasal tract meningiomas diagnosed between 1970 and 1992 were retrieved from the files of the Otorhinolaryngic Registry of the AFIP. Histologic features were reviewed, immunohistochemical studies were performed, patient follow up was obtained, and the results were statistically analyzed. The patients included 15 females and 15 males, aged 13 to 88 years (mean, 47.6 yrs). Patients presented clinically with a mass, epistaxis, sinusitis, pain, visual changes, or nasal obstruction, dependent on the anatomic site of involvement. Symptoms were present for an average of 31.1 months. The tumors affected the nasal cavity (n = 14), nasopharynx (n = 3), frontal sinus (n = 2), sphenoid sinus (n = 2). or a combination of the nasal cavity and ethmoid, frontal, sphenoid, and/or maxillary sinuses (n = 9). The tumors ranged in size from 1.0 to 8.0 cm in greatest dimension (mean, 3.5 cm). Radiographic studies demonstrated a central nervous system connection in six cases. The tumors often eroded the bones of the sinuses (n = 18) and involved the surrounding soft tissues, the orbit, and occasionally the base of the skull. Histologically, the tumors demonstrated features similar to intracranial meningiomas. The majority were of the meningothelial type (n = 23), although there were three atypical meningiomas. Immunohistochemical studies confirmed the diagnosis of meningioma with positive reactions for epithelial membrane antigen (EMA) and vimentin (all tested). The differential diagnosis includes paraganglioma, carcinoma, melanoma, psammomatoid ossifying fibroma, and angiofibroma. Surgical excision was used in all patients. Three patients died with recurrent disease (mean, 1.2 yrs), one was alive with recurrent disease (25.6 years), and the remaining 24 patients were alive or had died of unrelated causes (mean, 13.9 yrs) at the time of last follow up (two patients were lost to follow up). Extracranial sinonasal tract meningiomas are rare tumors which need to be considered in the differential diagnosis of sinonasal tumors. A whorled growth pattern and psammoma bodies, combined with positive EMA and vimentin immunohistochemical reactions, can confirm the diagnosis of meningioma. The overall prognosis is good, without a difference in outcome between benign and atypical meningiomas.

Mucinous cystic neoplasm (mucinous cystadenocarcinoma of low-grade malignant potential) of the pancreas: a clinicopathologic study of 130 cases.

Mucinous cystic neoplasms (MCNs) of the pancreas are uncommon tumors. The classification and biologic potential of these neoplasms remain the subject of controversy. Attempts to classify these tumors in a similar manner to ovarian MCNs remains controversial, as even histologically benign-appearing pancreatic MCNs metastasize and are lethal. One hundred thirty cases of MCNs were identified in the files of the Endocrine Pathology Tumor Registry of the Armed Forces Institute of Pathology from the years 1979 to 1993. The pathologic features, including hematoxylin and eosin staining, histochemistry, immunohistochemistry (IHC), cell cycle analysis, and K-ras oncogene determination were reviewed. These findings were correlated with the clinical follow-up obtained in all cases. There were 130 women, aged 20-95 years (mean age at the outset, 44.6 years). The patients had vague abdominal pain, fullness, or abdominal masses. More than 95% of the tumors were in the pancreatic tail or body and were predominantly multilocular. The tumors ranged in size from 1.5 to 36 cm in greatest dimension, with the average tumor measuring >10 cm. A spectrum of histomorphologic changes were present within the same case and from case to case. A single layer of bland-appearing, sialomucin-producing columnar epithelium lining the cyst wall would abruptly change to a complex papillary architecture, with and without cytologic atypia, and with and without stromal invasion. Ovarian-type stroma was a characteristic and requisite feature. Focal sclerotic hyalinization of the stroma was noted. This ovarian-type stroma reacted with vimentin, smooth muscle actin, progesterone, or estrogen receptors by IHC analysis. There was no specific or unique epithelial IHC. K-ras mutations by sequence analysis were wild type in all 52 cases tested. Ninety percent of patients were alive or had died without evidence of disease (average follow-up 9.5 years), irrespective of histologic appearance; 3.8% were alive with recurrent disease (average 10 years after diagnosis); and 6.2% died of disseminated disease (average 2.5 years from diagnosis). Irrespective of the histologic appearance of the epithelial component, with or without stromal invasion, pancreatic MCNs should all be considered as mucinous cystadenocarcinomas of low-grade malignant potential. Pancreatic MCNs cannot be reliably or reproducibly separated into benign, borderline, or malignant categories.

Lymphoid changes of the nasopharyngeal and palatine tonsils that are indicative of human immunodeficiency virus infection. A clinicopathologic study of 12 cases.

We report 12 cases in which the histomorphologic changes of the nasopharyngeal tonsils (adenoids) or palatine tonsils suggest infection with the human immunodeficiency virus (HIV). The patients included 10 men and two women, aged 20 to 42 years (median, 33 years). The clinical presentation included airway obstruction, pharyngitis, fever, and a tonsillar or adenoidal mass lesion. Histologic evaluation of the excised adenoids or tonsils in 10 of the cases demonstrated a spectrum of changes including florid follicular hyperplasia, follicle lysis, attenuated mantle zone, and the presence of multinucleated giant cells (MGC). The latter characteristically localized adjacent to the surface or tonsillar crypt epithelium. Two of the 12 cases showed marked lymphoid depletion with absent germinal centers, plasmacytosis, and stromal vascular proliferation. Immunohistochemical evaluation for HIV p24 core protein showed reactivity in 10 of 12 cases localized to follicular dendritic cell network (FDC), the MGC, scattered interfollicular lymphoid cells, and cells identified within the surface or crypt epithelium. Localization of viral RNA by in situ hybridization paralleled the HIV p24 immunohistochemical findings. Additional significant findings included the presence of both CD-68 and S-100 protein in the MGC and the presence of S-100 protein in dendritic cells. Other than HIV, no microorganisms were identified. At the time of presentation, eight patients were not known to be a risk for HIV infection, nor were they known to be HIV infected or suffering from AIDS. In these patients, HIV infection was suspected on the basis of the histologic changes seen in the resected tonsillar and adenoidal tissue. Serologic evaluation (by enzyme-linked immunosorbent assay), confirmed the presence of HIV infection. Our findings suggest the possibility of HIV dissemination through the upper aero-digestive tract mucosa via target cells, such as intraepithelial dendritic cells, submucosal macrophages, and T-lymphocytes. Subsequent presentation of viral antigens to the tonsillar and adenoidal lymphoid tissues results in enlargement of these structures that clinically may simulate a neoplastic proliferation but causes histomorphologic changes that are highly suspicious for HIV infection even in asymptomatic HIV-positive patients.

Malignant lymphoma of the thyroid gland: a clinicopathologic study of 108 cases.

We report a retrospective clinicopathologic study of 108 primary thyroid gland lymphomas (PTLs), classified using the REAL and proposed WHO classification schemes. The patients included 79 women and 29 men, with an average age of 64.3 years. All patients presented with a thyroid mass. The PTLs were classified as marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT) or MZBL (n = 30), diffuse large B-cell lymphoma (DLBCL) with MZBL (n = 36), DLBCL without MZBL (n = 41), and follicle center lymphoma (FCL; n = 1). Excluding the FCL, features of lymphomas of MALT-type were identified in all groups, despite a follicular architecture in 23% of cases. Lymphocytic thyroiditis (LT) was identified in 94%. Ninety-one percent of patients presented with stage IE or IIE disease, whereas 69% had perithyroidal soft tissue infiltration. All patients were treated with surgical excision followed by adjuvant therapy (76%): chemotherapy (15%), radiation (19%), or a combination of radiation and chemotherapy (42%). Disease-specific survival was 82% at last follow up (mean, 82.8 mos) and 79% at 5 years. Statistically, stages greater than IE, presence of DLBCL, rapid clinical growth, abundant apoptosis, presence of vascular invasion, high mitotic rate, and infiltration of the perithyroidal soft tissue were significantly associated with death with disease. No patients with MZBL or stage IE disease died with disease. In summary, PTLs typically occur in middle- to older-aged individuals as a thyroid mass, with a predilection for females. Despite their histologic heterogeneity and frequent simulation of other lymphoma subtypes, virtually all PTLs are lymphomas of MALT-type arising in the setting of LT. Mixed DLBCL and MZBL are common. Overall, PTLs have a favorable outcome with appropriate therapy, but prognosis depends on both clinical stage and histology. MZBL and stage IE tumors have an excellent prognosis, whereas tumors with a large cell component or DLBCL or stage greater than IE have the greatest potential for a poor outcome.

Mast cell involvement in fibrodysplasia ossificans progressiva.

Fibrodysplasia ossificans progressiva (FOP) is a catastrophic genetic disorder of progressive heterotopic ossification associated with dysregulated production of bone morphogenetic protein 4 (BMP4), a potent osteogenic morphogen. Postnatal heterotopic ossification in FOP is often heralded by hectic episodes of severe post-traumatic connective tissue swelling and intramuscular edema, followed by an intense and highly angiogenic fibroproliferative mass. The abrupt appearance, intense size, and rapid intrafascial spread of the edematous preosseous fibroproliferative lesions implicate a dysregulated wound response mechanism and suggest that cells and mediators involved in inflammation and tissue repair may be conscripted in the growth and progression of FOP lesions. The central and coordinate role of inflammatory mast cells and their mediators in tissue edema, wound repair, fibrogenesis, angiogenesis, and tumor invasion prompted us to investigate the potential involvement of mast cells in the pathology of FOP lesions. We show that inflammatory mast cells are present at every stage of the development of FOP lesions and are most pronounced at the highly vascular fibroproliferative stage. Mast cell density at the periphery of FOP lesional tissue is 40- to 150-fold greater than in normal control skeletal muscle or in uninvolved skeletal muscle from FOP patients and 10- to 40-fold greater than in any other inflammatory myopathy examined. These findings document mobilization and activation of inflammatory mast cells in the pathology of FOP lesions and provide a novel and previously unrecognized target for pharmacologic intervention in this extremely disabling disease.

Telecytology: intraobserver and interobserver reproducibility in the diagnosis of cervical-vaginal smears.

Telecytologic diagnosis of cervical-vaginal smears is potentially useful because it could allow more efficient use of cytopathologist resources and expertise. A pathologist in one location could, in principle, review cytotechnologists' findings using a video display hundreds or thousands of miles away. Currently, bandwidth restrictions limit practical implementation of such a system to review of fields that had been selected for review by the cytotechnologist. The purpose of our investigation was to evaluate how well this type of review correlates with a review in which the entire slide is available for examination by the pathologist. We prospectively selected 100 consecutive cervical-vaginal smears over an 11-day period in August 1999. For each smear, 4 to 12 fields containing abnormal cells from each slide were digitally imaged. Each of 3 pathologists reviewed all digitized images and all glass slides. Diagnoses based on selected digitized images were compared with those based on conventional pathologist review. The kappa statistic, a measure of chance-corrected agreement (reproducibility), was calculated in each setting. Overall, intraobserver and interobserver reproducibility of cervical-vaginal smear diagnoses is fair to excellent. The use of remote digital images for pathologist review did not introduce large (2-step) diagnostic disagreements. The disagreement between a pathologist's glass slide and digital diagnoses is less than that for different pathologists reviewing glass slides, although interobserver differences were even greater in the interpretation of digital images.

Cystic lesion of the thymus. An occasionally malignant cervical and/or anterior mediastinal mass.

Between 1965 and 1982, we treated 46 patients with cystic lesions of the thymus. Thirty patients had anterior mediastinal cysts, nine had cysts which were large enough to be both cervical and mediastinal, and seven had cervical cysts. The majority (40/46) presented with asymptomatic masses. Six patients presented with distinct complaints: dysphagia (four patients), hoarseness owing to vocal cord paralysis (one patient), and cervical pain (one patient). All six had benign thymic cysts. The diagnosis of a cystic mass was established prior to operation by ultrasonography and computed axial tomography in our last three patients. These two techniques delineated the capsule and the central fluid in those three cases. All 46 patients had the mass resected without mortality or significant morbidity, except for resection of the phrenic nerve in one patient with malignant cystic thymoma. Cervical cysts were excised through cervical incisions. Cysts located in the anterior mediastinum and cervical-mediastinal cysts required median sternotomy or right thoracotomy for successful resection. Pathological examination showed that 39 patients had benign thymic cysts, three had benign cystic thymoma, two had malignant thymoma, one had a seminoma arising in the thymus, and one had a lymphoblastoma. We believe that a cystic thymic mass which can be detected by ultrasonography and computed tomography, although usually benign, does not eliminate the possibility of malignancy, and resection, therefore, is indicated.

Early results of the extracardiac conduit Fontan operation.

BACKGROUND: Among the modifications of the Fontan operation, the extracardiac approach may offer the greatest potential for optimizing early postoperative ventricular and pulmonary vascular function, insofar as it can be performed with short periods of normothermic partial cardiopulmonary bypass and without cardioplegic arrest in most cases. In this study, we reviewed our experience with the extracardiac conduit Fontan operation, with a focus on early postoperative outcomes. METHODS AND RESULTS: Between July 1992 and April 1997, 51 patients (median age 4.9 years) underwent an extracardiac conduit Fontan operation. Median cardiopulmonary bypass time was 92 minutes and has decreased significantly over the course of our experience. Intracardiac procedures were performed in only 5 patients (10%), and the aorta was crossclamped in only 11 (22%). Intraoperative fenestration was performed in 24 patients (47%). There were no early deaths. Fontan failure occurred in 1 patient who was a poor candidate for the Fontan procedure. Transient supraventricular tachyarrhythmias occurred in 5 patients (10%). Median duration of chest tube drainage was 8 days. Factors significantly associated with prolonged resource use (mechanical ventilation, inotropic support, intensive care unit stay, and hospital stay) included longer bypass time and higher Fontan pressure. At a median follow-up of 1.9 years, there was 1 death from bleeding at reoperation. CONCLUSIONS: The extracardiac conduit Fontan procedure can be performed with minimal mortality and morbidity. Improved results may be related to advantages of the extracardiac approach and improved preservation of ventricular and pulmonary vascular function.