Cardiac toxoplasmosis after heart transplantation diagnosed by endomyocardial biopsy.

We describe a case of cardiac toxoplasmosis diagnosed by routine endomyocardial biopsy in a patient with trimethoprim-sulfamethoxazole (TMP-SMX) intolerance on atovaquone prophylaxis. Data are not available on the efficacy of atovaquone as Toxoplasma gondii prophylaxis after heart transplantation. In heart transplant patients in whom TMP-SMX is not an option, other strategies may be considered, including the addition of pyrimethamine to atovaquone.

New Insights on Diagnostic Reproducibility of Biphasic Mesotheliomas: A Multi-Institutional Evaluation by the International Mesothelioma Panel From the MESOPATH Reference Center.

INTRODUCTION: The 2015 WHO classification of tumors categorized malignant mesothelioma into epithelioid, biphasic (BMM), and sarcomatoid (SMM) for prognostic relevance and treatment decisions. The survival of BMM is suspected to correlate with the amount of the sarcomatoid component. The criteria for a sarcomatoid component and the interobserver variability between pathologists for identifying this component are not well described. In ambiguous cases, a "transitional" (TMM) subtype has been proposed but was not accepted as a specific subtype in the 2015 WHO classification. The aims of this study were to evaluate the interobserver agreement in the diagnosis of BMM, to determine the nature and the significance of TMM subtype, and to relate the percentage of sarcomatoid component with survival. The value of staining for BRCA-1-associated protein (BAP1) and CDKN2A(p16) fluorescence in situ hybridization (FISH) were also assessed with respect to each of the tumoral components. METHODS: The study was conducted by the International Mesothelioma Panel supported by the French National Cancer Institute, the network of rare cancer (EURACAN) and in collaboration with the International Association for the Study of Lung Cancer (IASLC). The patient cases include a random group of 42 surgical biopsy samples diagnosed as BMM with evaluation of SMM component by the French Panel of MESOPATH experts was selected from the total series of 971 BMM cases collected from 1998 to 2016. Fourteen international pathologists with expertise in mesothelioma reviewed digitally scanned slides (hematoxylin and eosin - stained and pan-cytokeratin) without knowledge of prior diagnosis or outcome. Cases with at least 7 of 14 pathologists recognizing TMM features were selected as a TMM group. Demographic, clinical, histopathologic, treatment, and follow-up data were retrieved from the MESOBANK database. BAP1 (clone C-4) loss and CDKN2A(p16) homozygous deletion (HD) were assessed by immunohistochemistry (IHC) and FISH, respectively. Kappa statistics were applied for interobserver agreement and multivariate analysis with Cox regression adjusted for age and gender was performed for survival analysis. RESULTS: The 14 panelists recorded a total of 544 diagnoses. The interobserver correlation was moderate (weighted Kappa = 0.45). Of the cases originally classified as BMM by MESOPATH, the reviewers agreed in 71% of cases (385 of 544 opinions), with cases classified as pure epithelioid in 17% (93 of 544), and pure sarcomatoid in 12% (66 of 544 opinions). Diagnosis of BMM was made on morphology or IHC alone in 23% of the cases and with additional assessment of IHC in 77% (402 of 544). The median overall survival (OS) of the 42 BMM cases was 8 months. The OS for BMM was significantly different from SMM and epithelioid malignant mesothelioma (p < 0.0001). In BMM, a sarcomatoid component of less than 80% correlated with a better survival (p = 0.02). There was a significant difference in survival between BMM with TMM showing a median survival at 6 months compared to 12 months for those without TMM (p < 0.0001). BAP1 loss was observed in 50% (21 of 42) of the total cases and in both components in 26%. We also compared the TMM group to that of more aggressive patterns of epithelioid subtypes of mesothelioma (solid and pleomorphic of our large MESOPATH cohort). The curve of transitional type was persistently close to the OS curve of the sarcomatoid component. The group of sarcomatoid, transitional, and pleomorphic mesothelioma were very close to each other. We then considered the contribution of BAP1 immunostaining and loss of CDKN2A(p16) by FISH. BAP1 loss was observed in 50% (21 of 41) of the total cases and in both component in 27% of the cases (11 of 41). There was no significant difference in BAP1 loss between the TMM and non-TMM groups. HD CDKN2A(p16) was detected in 74% of the total cases with no significant difference between the TMM and non-TMM groups. In multivariate analysis, TMM morphology was an indicator of poor prognosis with a hazard ratio = 3.2; 95% confidence interval: 1.6 - 8.0; and p = 0.003 even when compared to the presence of HD CDKN2A(p16) on sarcomatoid component (hazard ratio = 4.5; 95% confidence interval: 1.2 - 16.3, p = 0.02). CONCLUSIONS: The interobserver concordance among the international mesothelioma and French mesothelioma panel suggests clinical utility for an updated definition of biphasic mesothelioma that allows better stratification of patients into risk groups for treatment decisions, systemic anticancer therapy, or selection for surgery or palliation. We also have shown the usefulness of FISH detection of CDKN2A(p16) HD compared to BAP1 loss on the spindle cell component for the separation in ambiguous cases between benign florid stromal reaction from true sarcomatoid component of biphasic mesothelioma. Taken together our results further validate the concept of transitional pattern as a poor prognostic indicator.

Reference weights for placentas delivered before the 28th week of gestation.

CONTEXT: Very few studies have measured the weight of large numbers of placentas delivered before the 28th post-menstrual week. METHODS: We measured the weight of 930 singleton placentas delivered before the 28th post-menstrual week, and examined the distributions of weights in selected groups (week of gestation, reason for preterm birth, birth weight Z-score categories, placenta histology). We excluded 90 singleton placentas based on growth restriction as indicated by birth weight Z-score, resulting in a normative sample of 840 placentas. Weights for unfused twin placentas are also presented. RESULTS: Standard weights derived from our data set differ from those previously published, partly due to a larger sample size. Placenta weight varied with birth weight. Placentas from pregnancies ending due to preeclampsia, fetal indications or those showing evidence of poor perfusion on histology were among the smallest and their weights correlated with the smallest birth weights for gestational age. CONCLUSIONS: Placenta weights appear to be influenced by multiple maternal and fetal processes. We present a standard weight table for singleton placentas among live infants born between 23 and 27 completed weeks.

Low rate of acute lung allograft rejection after the use of daclizumab, an interleukin 2 receptor antibody.

BACKGROUND: The incidence and the severity of acute lung allograft rejection has been linked to the development of bronchiolitis obliterans syndrome. Therefore, we investigated the effects of daclizumab, a humanized monoclonal antibody directed against the alpha subunit of the interleukin 2 receptor, in reducing acute rejection after transplantation. METHODS: We retrospectively evaluated 27 patients who received daclizumab as induction immunosuppression and compared them with a historical control group of 34 patients. Both groups received similar immunosuppressive regimens involving tacrolimus, prednisone, and either azathioprine or mycophenolate mofetil. All patients received cytomegalovirus and aspergillus prophylaxis. RESULTS: Twenty-one patients in the control group and 22 patients in the daclizumab group were available for analysis at 6 months after lung transplantation. Ten (48%) patients in the control group had at least grade 2 acute rejection compared with four (18%) in the daclizumab group (P<0.04). The incidence of infection was similar in both groups. One patient in each group developed posttransplant lymphoproliferative disease. CONCLUSION: Therapy with daclizumab resulted in a significant decrease in the incidence of grade 2 or greater acute rejection after lung transplantation compared with historical controls. There seems to be no increase in the incidence of adverse effects in the patients treated with daclizumab.

Bronchiolitis obliterans organizing pneumonia-like reactions: a nonspecific response or an atypical form of rejection or infection in lung allograft recipients?

Bronchiolitis obliterans organizing pneumonia (BOOP) is a ubiquitous entity, known to occur either idiopathically or in association with various pulmonary disorders. Histologically, it is characterized by myxomatous connective tissue plugs present in the lumen of bronchioles with extension into the alveoli. Its significance in lung allograft recipients is not well documented. The authors reviewed all post-lung transplant biopsies (565 transbronchial; 19 open), explanted lungs for retransplantation (six), and autopsies (38) from 115 patients. A total of 32 patients (18 females and 14 males) showed histological evidence of BOOP-like reactions (ie, Masson bodies in 44 transbronchial and seven open lung biopsies). The mean age was 47 years (range = 14 to 69 years). Sixteen patients were recipients of single lungs, 14 received bilateral single lungs, and two had heart and double-lung transplants. BOOP-like reactions (BOOP-LRs) occurred as early as day 5 and as late as day 1,208 (40 months) posttransplantation. Twenty patients had one biopsy showing BOOP-LR, of which three patients had resolving mild acute rejection, four had ongoing minimal acute rejection, seven had ongoing mild acute rejection, one each had ongoing moderate and bronchiolar rejection, and four showed associated cytomegalovirus (CMV) pneumonitis. Seven patients had two biopsies each of BOOP-LR of which six were associated with ongoing minimal or mild acute rejection, and one had resolving mild acute rejection. Three patients had three biopsies each of BOOP-LR all associated with ongoing minimal or mild acute rejection. Two patients had four biopsies each, showing BOOP-LR, with ongoing mild or moderate acute rejection or CMV pneumonitis. Forty of the total 115 lung transplant patients (34.8%) have developed bronchiolitis obliterans syndrome (BOS) or chronic airway rejection. Twelve of these patients are from the study group, of which five have a biopsy proven histological diagnosis of obliterative bronchiolitis (OB), and the remaining seven patients have been diagnosed clinically by deteriorating lung function tests. The authors conclude that BOOP-LR in the lung transplant setting result from acute epithelial injury secondary to either allograft rejection or an ongoing infection and are not a component of, nor do they necessarily predispose to, chronic rejection.

Pathology of arrested acinar development in postsurfactant bronchopulmonary dysplasia.

To define the pathology of bronchopulmonary dysplasia (BPD) in surfactant-treated patients (S-BPD), we reviewed 22 BPD patients (14 S-BPD and eight non-surfactant-treated [NS-BPD]) and 15 age-matched controls, the lungs from which had been processed after formalin inflation. These were studied for surfactant therapy, postconceptional age, crown-rump length, weight at autopsy, radial alveolar count (RAC), mean linear intercept (MLI), RAC/MLI ratio, and amount and extent of fibrosis. On trichrome staining, there was no alveolar septal fibrosis in the control group, whereas there was mild to moderate alveolar septal fibrosis in 5 of 14 S-BPD patients, of which three had fibrosis in most or all of the acini. In contrast, seven of eight NS-BPD had moderate to severe alveolar septal fibrosis in scattered acini throughout the lung. The patients were divided into two groups, with the first group having a postconceptional age at the time of death of up to 40 weeks' gestation. In group 1, the RAC in S-BPD (nine patients) was significantly lower than that of the controls (seven patients); mean, 4.14 and 5.13, respectively (P = .016), whereas the RAC in the NS-BPD (four patients) and the MLI in both S-BPD and NS-BPD were not statistically significantly different. In group 2, those with adjusted age greater than term, the mean RAC, a measure of acinar complexity, was 3.89 in the S-BPD (five patients) and 3.90 in the NS-BPD (four patients), whereas in the control group (eight patients), it was 5.79 (P = .0007). The mean MLI, a measure of alveolar size, was 0.21 and 0.17 in the S-BPD and NS-BPD groups, respectively, each of which was significantly greater than the mean value of 0.12 in the control group (P = .0003). The comparison of RAC/MLI ratios showed similar statistically significant differences. Based on these results, we conclude that (1) the amount of alveolar septal fibrosis is substantially less and tends to be more diffuse in S-BPD than in NS-BPD; (2) during the period after birth, there is a partial to complete arrest in acinar development (alveolar saccular and alveolar) of similar severity for S-BPD and NS-BPD; and (3) even though on histological examination there are minimal changes, RAC, MLI, and their ratio may be used to support the diagnosis of BPD and help in assessing the amount of lung damage that occurs in S-BPD.

Low-grade myxoid renal epithelial neoplasms with distal nephron differentiation.

We report 4 distinctive renal epithelial neoplasms that are essentially identical at the morphologic and immunohistochemical levels and do not fit an accepted category in the existing classification of these lesions. The patients were all females, with ages ranging from 32 to 79 years (mean, 50 years). The tumors were well circumscribed and were composed of uniform, predominantly low cuboidal cells with eosinophilic, focally vacuolated cytoplasm. Tumor cells generally formed interconnecting tubules, with smaller areas of cordlike growth and spindling in a bubbly, myxoid stroma. All tumors were confined to the kidney, and all were immunoreactive for high-molecular-weight cytokeratin 34betaE12, cytokeratin 7, epithelial membrane antigen, and cytokeratin cocktail AE1/3. Only 1 tumor was focally immunoreactive for Ulex europaeus agglutinin. Ultrastructural study showed tumor cells forming tubular structures reminiscent of the loop of Henle or distal convoluted tubule. Follow-up in all 4 cases was benign. These distinctive tumors may be confused with aggressive sarcomatoid renal cell carcinomas because of their spindled morphology. The morphologic, immunohistochemical, and ultrastructural features of these lesions indicate differentiation toward distal nephron segments. Similar tumors probably have been reported among low-grade collecting duct carcinomas or tumors "possibly related to the loop of Henle."

Donor lung pathology: correlation with outcome of transplanted contralateral lung.

To compare clinical results of single lung transplantation with pretransplantation pathology, we reviewed 15 human lungs from 12 donors, which clinically satisfied donor lung criteria but were not transplanted. In nine of these cases the contralateral lung was transplanted. Seven of these nine unused lungs showed mild pathologic changes, including emphysema, focal fibrosis, and old and recent hemorrhage, which had no impact on the outcome of the transplanted contralateral lung. One case had moderate generalized emphysema, which also did not affect the outcome because the other lung was given to a patient with severe emphysema. One donor lung showed severe overinflation artifact, which we think contributed to the early graft failure in a patient with primary pulmonary hypertension. We conclude that, despite satisfying standard donor lung criteria, many lungs have abnormal pathology. This may impact both short- and long-term survival.

Humoral (antibody-mediated) rejection in lung transplantation.

To confirm the existence and characterize the pathologic features of humoral (antibody-mediated) lung rejection, we prospectively studied 55 lung transplant recipients (24 male [44%] and 31 female [56%], age range 14 to 69 years [mean 45]). The time between transplantation and biopsy ranged from 2 to 1546 days (mean 274). We performed direct immunofluorescence with C3, immunoglobulin M, and immunoglobulin G antibodies on frozen sections of 106 transbronchial biopsies and one wedge biopsy and compared the results with 13 explanted lungs, one donor lung, and two controls. The histologic diagnoses of these 107 biopsies included acute cellular rejection (62, 58% [minimal 23, mild 33, moderate 5, and severe 1]), chronic rejection (eight, 7%), chronic vascular rejection (two, 2%), acute vasculitis (five, 5%), cytomegalovirus pneumonitis (two, 2%), acute pneumonia (two, 2%), acute organizing pneumonia (two, 2%), diffuse alveolar damage (one, 1%), no evidence of rejection or infection (30, 28%), lipoid pneumonia (one, 1%), and inadequate for histologic diagnosis (one, 1%). Eighty-nine of 106 (84%) transbronchial biopsies, the wedge biopsy, and control lungs were satisfactory for direct immunofluorescence, because each contained alveolate lung parenchyma and arterioles or venules. There was no demonstrable immunofluorescence in the wall of the blood vessels or in the lung parenchyma in any case. We conclude that (1) transbronchial biopsies and wedge biopsies provide adequate material to evaluate humoral rejection, and (2) in spite of the large population studied, the satisfactory material obtained, and the wide range of histologic diagnoses, we could not demonstrate the occurrence of humoral rejection in the lung.

Quantification of cytomegalovirus (CMV) viral load by the hybrid capture assay allows for early detection of CMV disease in lung transplant recipients.

BACKGROUND: We prospectively compared the hybrid capture system (HCS) assay with conventional cell culture and shell vial assay for the detection of cytomegalovirus (CMV) infection and disease in the lung transplant population. METHODS: Between January 1999 and February 2000, 34 lung transplant patients at Loyola University Medical Center, who were considered to be at risk for CMV disease, underwent surveillance testing for CMV cell culture, shell vial assay and HCS assay according to a pre-determined schedule. In addition, bronchoscopy with bronchoalveolar lavage (BAL) and transbronchial biopsy were performed at regular intervals and for clinical indications. All BAL samples were sent for CMV cultures and biopsy specimens were analyzed for histopathologic evidence of CMV by immunoperoxidase staining using antibody to early immediate nuclear antigen. RESULTS: Ten patients developed CMV disease/syndrome during the course of the study. The sensitivity, specificity, positive predictive value and negative predictive value were >90% for the HCS assay. The sensitivity of the HCS assay (90%) was statistically significantly higher than the sensitivity of either the SV assay (40%) or the cell culture (50%). In addition, the HCS assay was able to detect CMV 50 +/- 67 days prior to clinical evidence of CMV disease and an average of 36 days prior to the other detection techniques. CONCLUSION: The HCS assay is a sensitive diagnostic technique able to reliably detect CMV disease earlier than other diagnostic methods in the lung transplant population. Future studies may be able to evaluate whether pre-emptive anti-viral therapy targeted to specific viral loads using the HCS assay will be beneficial in preventing morbidity associated with CMV disease.

Revision of the 1990 working formulation for the classification of pulmonary allograft rejection: Lung Rejection Study Group.

In 1990, an international grading scheme for the grading of pulmonary allograft rejection was instituted. The use of this classification has resulted in a uniformity of grading which has allowed inter-institutional collaborations and communication unique in allograft monitoring. In 1995 an expanded group of international pathologists convened and revised the original proposal. This article summarizes the updated classification for pulmonary allograft rejection. In brief, acute rejection is based on perivascular and interstitial mononuclear infiltrates. Each grade of acute rejection should mention the presence of coexistent airway inflammation, the intensity of which may also be graded. Chronic rejection is divided into bronchiolitis obliterans--active or inactive--and vascular atherosclerosis--accelerated arterial or venous sclerosis.

Mycobacterial DNA in recurrent sarcoidosis in the transplanted lung--a PCR-based study on four cases.

Sarcoidosis is a systemic granulomatous inflammation, which may be caused by mycobacteria other than M. tuberculosis complex (MOTT) in one-third of cases. A few cases of recurrent sarcoidosis in the transplanted lung have been reported. However, mycobacteria have been excluded by acid-fast stains only. We investigated four cases of recurrent sarcoidosis in lung transplant patients. Using PCR for the insertion sequence 6110 of Mycobacterium tuberculosis complex and a second PCR for the mycobacterial chaperonin (65-kDa antigen coding sequence), we looked for mycobacterial DNA. In three cases sequence analysis was also performed. One patient was negative for mycobacterial DNA in explanted, but positive for M. tuberculosis DNA in transplanted lung, qualifying this case as M. tuberculosis infection in the transplant. Three patients were negative for M. tuberculosis DNA, but were positive for MOTT-DNA in both explanted and transplanted lungs. In these three patients sequence identity of the amplified sequences before and after transplantation was proven, which rules out mycobacteriosis. Recurrent sarcoidosis does occur, but can only be proven by the exclusion of mycobacterial DNA. In cases of recurrent MOTT-DNA-positive sarcoidosis the diagnosis cannot be confirmed except by proof of sequence identity. Probably MOTT-DNA-positive sarcoidosis is more likely to recur in a transplanted lung.

Cerebral astroblastoma: immunohistochemical and ultrastructural features. Case report.

Astroblastoma is a rare glial tumor occurring predominantly in the cerebral hemispheres of young adults. Foci of astroblastoma-like patterns are commonly found in glioblastomas and other malignant glial tumors and cause confusion over the classification of the tumor as an individual entity. However, the existence of astroblastoma in histologically pure form and its typically long history, as compared with the more aggressive gliomas in which it may occur as a pattern, distinguish it as a separate and distinct tumor. A case of pure astroblastoma of the cerebral hemisphere is reported in a 3-year-old child with a 5-year course. The tumor has been resected five times, and its pattern has remained the same in all recurrences. The child is presently alive with some neurological deficit. The immunohistochemical and electron microscopical findings of this tumor are presented, and the historical development of the entity is discussed.

Disseminated herpes simplex virus infection presenting as fever in the newborn--a lethal outcome.

The clinical course of a neonate who presented with fever and tachypnea on day 6 of life is described. He developed disseminated intravascular coagulopathy, hepatic failure, coma and expired at 14 days of age. The post mortem viral cultures from liver, adrenal and lungs were positive for HSV type 2. The fatal outcome of this case of fever, due to HSV infection, emphasizes the need for early treatment of suspicious cases of HSV infection. HSV should be considered in the differential diagnosis of the newborn with persistent fever unresponsive to antibiotics.

Synchronous adenocarcinomas of jejunum and cecum following transverse colon carcinoma. A case study.

A case of synchronous primary adenocarcinomas of the small and large bowel in a patient previously treated by transverse colectomy for cancerous polyps is presented. These new primaries were incidental findings during surgery for suspected recurrence of colonic carcinoma. Primary tumors of the small bowel are rare, and the diagnosis of primary adenocarcinoma of small bowel in the presence of primary adenocarcinoma of large bowel requires a high degree of suspicion and may well modify the prognostic outcome if detected early.

The laparoscopic cooling sheath: novel device for hypothermic preservation of kidney during temporary renal artery occlusion.

Hypothermia is commonly used to prevent ischemic renal damage during complex nephron-sparing surgical procedures requiring temporary renal artery occlusion. We developed a novel Cooling Sheath device, which is compatible with laparoscopy, to protect the kidney hypothermically during 60 minutes of temporary arterial occlusion in a laparoscopic swine model. Comparison of temperature curves and histology to control groups undergoing open slush surface cooling and laparoscopic warm ischemia for similar time periods was performed. Optimal hypothermic temperatures were reached rapidly and maintained with the use of the Cooling Sheath. Ischemic damage, present in all kidneys subjected to warm ischemia, was not found on histopathologic examination of the cooled kidneys. This new device provides hypothermic protection of the kidney during ischemia. The use of the Cooling Sheath combined with temporary arterial occlusion will allow more complex nephron-sparing renal surgery to be performed using laparoscopy.

Primary malignant melanoma of the larynx.

Primary malignant melanoma of the larynx is a rare clinical entity. Only 53 cases have been reported in the medical literature to date. This report describes a case of primary malignant melanoma arising in the larynx and diagnosed by histologic examination of an excisional biopsy specimen. The patient was a 53-year-old man with a history of smoking and hoarseness. There was no clinical evidence of other primary malignant melanocytic lesions. Microscopically, the tumor consisted of polygonal-epithelioid cells admixed with more elongated, spindle-shaped cells. The majority of the cells demonstrated dark brown cytoplasmic and nuclear melanin. Marked pleomorphism and abnormal mitoses were also identified. Despite significant ulceration and disruption of the epithelium, in situ malignant melanocytes were recognized within the remaining portion of the epithelium. Immunohistochemical studies were positive for S100, HMB-45, and vimentin, while cytokeratin and iron stains were negative. Based on the clinical and histologic findings, a diagnosis of primary malignant melanoma of the larynx was established.

Early diagnosis of cytomegalovirus pneumonitis in lung transplant patients.

Cytomegalovirus (CMV) pneumonitis is an important cause of morbidity and mortality in lung transplant patients and requires timely and accurate diagnosis. This study compares the diagnostic utility of the evaluation of transbronchial biopsy by histology, immunohistochemistry, and simultaneous culture of bronchoalveolar lavage in a population of 13 lung transplant patients who underwent 78 biopsies during a period of 27 months. Our study concludes that, in patients clinically symptomatic for CMV pneumonitis, histology alone is diagnostic for the presence of the virus, whereas culture of bronchoalveolar lavage fluid is not as helpful. In asymptomatic patients, however, immunohistochemistry utilizing monoclonal antibodies to immediate-early and early CMV nuclear antigens may indicate development of CMV pneumonitis before cytopathic changes are evident.

Mesenteric defects as a cause of intestinal volvulus without malrotation and as the possible primary etiology of intestinal atresia.

Mesenteric defects can lead to intestinal volvulus even when the midgut is normally rotated. There are two types of mesenteric defects: basilar, in which the entire base of the mesentery is involved, and segmental, in which only an isolated portion of the mesentery is affected. These defects can present at any age, and the clinical symptoms depend on the extent of the disease and the amount of intestine involved in the volvulus. In the newborn, the basilar defects have clinical signs and symptoms similar to those of midgut volvulus secondary to malrotation. Similar to midgut volvulus secondary to malrotation, this is a surgical emergency. In older patients, basilar defects can be misdiagnosed because of the normal placement of the ligament of Treitz and because of failure to consider mesenteric defects as a possible cause. The treatment for basilar mesenteric defects is intestinal fixation. Intestinal volvulus secondary to segmental defects always presents as intestinal obstruction. In the newborn, these lesions may be indistinguishable from intestinal atresia. Older children present with intestinal obstruction of an unknown cause. Resection of the affected intestine is the treatment for segmental mesenteric defects. Intestinal mesenteric abnormalities as a cause of intestinal atresia unifies under one etiology all the lesions observed in intestinal atresia. Although this theory does not rule out other causes of intestinal atresia, intestinal mesenteric defects may be the primary condition under which intestinal atresia occurs.

Bronchioloalveolar lavage in the diagnosis of CMV pneumonitis in lung transplant recipients: an immunocytochemical study.

Cytomegalovirus (CMV) pneumonitis is a common opportunistic infection in lung transplant recipients. Its diagnosis usually rests on the identification of viral inclusions in lung parenchyma obtained by transbronchial biopsy, or by examination of the cytologic material obtained by bronchioloalveolar lavage (BAL). To determine whether the use of immunocytochemistry (ICC) increases the sensitivity of cytology in the diagnosis of CMV pneumonitis, we retrospectively selected 17 cases in which transbronchial biopsy and BAL were performed simultaneously, and had positive histology with negative cytology. Five negative controls were selected. The 22 slides were decolorized and restained with ICC for CMV. Of the 17 slides, nine (53%) showed cells with positive nuclear staining. All controls were negative. These results were then correlated with the number of infected cells present in the biopsy tissue, and the location of the cells (interstitial vs. intraalveolar). A good correlation was found between positive cytology and intraalveolar location of infected cells, and no correlation was seen between number of infected cells in the biopsy and the positive cytology. In summary, although histologic evaluation of lung parenchyma obtained by transbronchial biopsy is more sensitive for diagnosis of CMV pneumonitis, the sensitivity of the cytologic evaluation of BAL material can be increased by the use of ICC. The likelihood of positive ICC seems to be related to the presence of infected cells in the alveolar space rather than to the number of infected cells.