Phosphatidylglycerol in amniotic fluid. Comparison of an "ultrasensitive" immunologic assay with TLC and enzymatic assay

Phosphatidylglycerol (PG) in amniotic fluid is recognized as a good indicator of fetal lung maturity and is unaffected by moderate amounts of blood or meconium contamination. A rapid immunologic agglutination assay, Ultrasensitive AmnioStat-FLM (FLM), was compared with two-dimensional thin-layer chromatography (TLC) and an enzymic, colorimetric procedure (E-PG). Eighty amniotic fluid specimens were analyzed. FLM results were reported as high (H), intermediate (I), or low positive (L). TLC was compared with FLM:H (n = 27), mean 0.14 (fraction of total phospholipids); I (n = 7), mean 0.11; L (n = 9), mean 0.03; negative results had no detectable PG by TLC. In 33 cases E-PG was compared with FLM:H (n = 9), mean 7.0 mumol/L; I (n = 5), mean 8.1 mumol/L; L (n = 3), mean 3.0 mumol/L; negative (n = 16), mean 3.2 mumol/L. Records were reviewed in 70 cases. Thirty cases were excluded: sample to delivery time was greater than 72 hours; steroids were given or sepsis was documented. Fetal lung immaturity was clinically present in six cases: respiratory distress syndrome in three cases and transient tachypnea of the newborn (TTN) in three cases. One false positive result was identified (TTN, FLM:H). FLM sensitivity for fetal lung maturity was 85.3%, specificity was 83.3%, and the positive predictive value for fetal lung maturity was 96.7%. FLM is a fast, reliable indicator of fetal lung maturity.     

Is Severity of Respiratory Disease Associated With Differences in Neurodevelopmental Patterns in Preterm Infants?

Neurodevelopmental outcomes were assessed at 6, 12, and 24 months of age for preterm infants (PT; n = 169) and full-term infants (FT; n = 120) to determine if neurodevelopmental patterns were related to severity of respiratory diagnosis, especially for infants with chronic lung disease. PT infants' respiratory diagnoses were either acute (transient respiratory distress: n = 55; respiratory distress syndrome: n = 48) or chronic (chronic pulmonary insufficiency of the preterm [CPIP]: n = 30; bronchopulmonary dysplasia [BPD]: n = 36). BPD and CPIP infant groups showed no differences in neurodevelopmental patterns, and both groups displayed poorer development in cognitive, language, daily living, and motor skills and more persistent neurological abnormalities across 24 months than infants with less severe respiratory diagnoses and FT infants.     

Severe respiratory distress due to ileal duplication cyst in the newborn

Differential diagnosis of neonatal respiratory distress includes pulmonary and systemic disorders and anatomic problems compromising respiratory system. We report on a 2770-g female born to a 29-year-old gravida 3, para 2 woman after 34 weeks of gestation. Antenatal ultrasound performed in week 8 and 21 was normal. The infant was delivered by cesarean section after amniotic membranes had been ruptured for less than 12 hours due to signs of fetal distress. The Apgar score was 3 and 3 at 1 and 5 minutes, respectively. The infant was intubated and resuscitated, and transferred immediately to the neonatal intensive care unit. She had an extremely protuberant and cyanotic abdomen. Dilated cutaneous collateral vessels were apparent in the periumbilical region. Abdominal sonography showed cystic multiloculated tumorous mass filled with dense, flocculent content at the level of hepatic portal. The tumorous mass occupied the majority of the abdomen with caudal extension toward the pelvis and dorsally toward the spine. The liver was displaced high under the diaphragm with the left liver lobe in the left hemiabdomen. On x-ray the lung were collapsed due to a large abdominal mass in the right hemiabdomen that displaced the right diaphragm and intestines contralaterally. She soon developed bilateral pneumothoraces. Drainage and continuous suction were started. The infant failed to improve despite all attempts and died. On autopsy, an extremely large, mobile, multichambered, solitary cyst was found. It was attached to the mesenteric side of the ileum by its own thin peduncular stalk and had no communication with the remainder of the gut. It occupied the majority of the abdomen. Histologic section revealed a well-developed smooth muscle wall and inner mucosa of small bowel type. Respiratory distress is a common problem in premature infants. The majority of cases are due to pulmonary disorders (e. g., hyaline membrane disease, meconium aspiration syndrome, pneumonia), hypothermia, metabolic acidosis, anemia, and congenital heart disease. Anatomic problems including space occupying lesions are less common. Duplications of the alimentary tract in infants and children are rare congenital anomalies. Although symptoms can occur at any age, they usually present during the first year. In our patient, intraabdominal mass caused severe respiratory distress and respiratory failure in the first hours of postnatal life. This had been seen before only as a complication of intrathoracic lesions extending into the abdominal cavity. Pathology revealed spherical intestinal duplication that was completely separated from the alimentary tract. Embryologically, it was a localized duplication. Respiratory distress in our patient was refractory to all means of mechanical ventilation. Poor lung compliance was the consequence of prenatal lung hypoplasia and inadequate postnatal lung expansion due to the duplication cyst space occupying character and its compressive effect. Prenatal diagnosis was the child's only chance for survival but it was not made. Duplications of the alimentary tract can present a diagnostic challenge even in the first hours of life. They should be included in the differential diagnosis of severe respiratory distress, especially in premature infants in which timely prenatal diagnosis cannot be always made. We propose their inclusion among other space occupying lesions that might be the cause of severe respiratory distress even in the earliest neonatal period.     

Admission to neonatal intensive care with respiratory morbidity following 'term' elective caesarean section

Delaying the timing of elective caesarean section (ELCS) from 37/38 weeks to 39/40 weeks reduces the risk of respiratory morbidity in otherwise healthy neonates. The aims of this study were to clarify the number and clinical details of term infants delivered by ELCS who were admitted to neonatal intensive care (NIC) from 1st April 2001 to 31st March 2002 in Northern Ireland, to record the level of care required by these infants and to identify infants who were diagnosed with transient tachypnoea of the newborn (TTN) and/or Respiratory Distress Syndrome (RDS). Two hundred and ten (8%) of babies born by ELCS were admitted to NIC. Term infants delivered by ELCS used 343 days of level 1 & 2 care with 230 (68%) of these days being used by infants with RDS/TTN (n=105) the majority of whom were delivered at 37/38 weeks. Definitions of 'term' and clinical indications for ELCS urgently need to be debated to avoid unnecessary morbidity following ELCS in so called 'term' infants.     

Congenital diaphragmatic hernia in older children

The incidence of congenital diaphragmatic hernia (CDH) is about 4.8/10,000 live births. Its typical clinical presentation is respiratory distress occurring immediately after birth or in the first few hours or days of a child's life. It is characterized by a high mortality rate. Exceptionally, CDH can occur at an older age, its symptoms then frequently reflecting gastrointestinal obstruction or mild respiratory symptoms. In such cases CDH presents a far more complex diagnostic problem. The paper presents the cases of two girls without typical symptomatology, aged 5.5 and 10 years, in whom CDH was detected incidentally upon thorough physical examination and chest x-rays. Further radiographic evaluation, which included barium contrast study and spiral computed tomography, confirmed the suspicion of a left-sided posterolateral diaphragmatic hernia with associated intestinal malrotation. Surgical intervention conclusively confirmed a diaphragmatic defect at the site of Bochdalek's foramen in both cases. The vital capacity of the older girl, which was low before the surgery (VC 1.66 L; 69% of predicted), was significantly increased a month after the surgical treatment (VC 2.25 L; 92% of predicted). The generally expressed view that the clinical onset of CDH is rare after the neonatal period seems to be erroneous. Some papers report on the clinical presentation of CDH after the neonatal period in as many as 13%-14% of infants and young children suffering from CDH. Infants and young children with a delayed clinical occurrence of CDH can present with respiratory or gastrointestinal symptomatology. Children presenting with gastrointestinal symptoms have been shown to be significantly older than those presenting with respiratory symptoms. In older children and adolescents, the symptoms and signs of CDH, which include acute hernial incarceration, nausea, recurrent vomiting, diarrhea, obstipation, acute gastric dilatation, subcostal pain, failure to thrive and recurrent chest infections, habitually present a significant diagnostic problem. Diagnostic errors are mainly due to the fact that the possibility of CDH in that age is totally neglected. The most recurrent diagnostic misinterpretations in such cases are pneumonia or massive pleuropneumonia, empyema, pneumothorax, lung cysts and bullae, and gastric volvulus. Thus, whenever a child presents with uncommon respiratory or gastrointestinal symptoms and an anomalous chest x-ray, a differential diagnosis of CDH should be considered. Otherwise, an accurate diagnosis in both young and older children will most probably be only reached at autopsy. In conclusion, the presented cases corroborate the finding that CDH in older children may present with scarce symptoms, mostly gastrointestinal, or may be altogether asymptomatic and unrecognized until as late as adolescence. However, when a diagnosis of CDH has been established, albeit asymptomatic, it must be promptly treated surgically in order to prevent complications, such as strangulation or bowel perforation, and thus avert a potentially fatal outcome. The size itself of the herniac foramen is unlikely to be a determining factor at the time of clinical presentation of CDH. Surgical occlusion of CDH may in older children result in an improved vital capacity, as such cases are rarely associated with major pulmonary hypoplasia. Complications resulting from surgical treatment of CDH in older children are more likely to occur in the gastrointestinal system, as a consequence of the associated bowel malrotation and inadequate bowel fixation. Finally, these two cases corroborate the diagnostic value of accurate history taking and thorough physical examination.     

The association of rhinoviruses with lower respiratory tract disease in hospitalized patients

An analysis of 32 hospitalized infants and children from whom rhinoviruses were isolated in our diagnostic laboratories in 1982-83 suggests that these agents are associated with lower respiratory tract disease with focal findings in susceptible patients. In 23 cases, an acute lower respiratory disease was the cause for admission, while nine patients were cultured after new respiratory symptoms developed during hospitalization. Presenting signs and symptoms included cough (23), fever (19), rhinorrhea (19), respiratory distress (14), and decreased feeding (15). Seventeen of 25 chest x-rays showed new focal abnormalities. Twenty-five patients had a significant underlying disease including seven with malignancies, six with respiratory tract abnormalities, and four with congenital heart lesions. Six of the remaining seven patients were less than 2 1/2 months of age. In no cases were significant bacterial or fungal pathogens isolated; two did have concomitant viral isolates. Rhinoviruses in the appropriate clinical setting are associated with significant pulmonary disease.     

Atypical Cystic Fibrosis and CFTR-Related Diseases

Cystic fibrosis (CF), which is among the most common life-shortening recessive illnesses, is caused by mutations of the CF transmembrane conductance regulator (CFTR) and typically involves chronic infection and progressive obstruction of the respiratory tract as well as pancreatic exocrine insufficiency. Disease severity, to some extent, correlates with organ sensitivity to CFTR dysfunction and to the amount of functional protein, which is influenced by the type of mutation. Atypical CF represents approximately 2% of affected individuals, and includes cases presenting in adolescence or adulthood with pancreatic exocrine sufficiency, normal or borderline sweat chloride concentrations, or with a single predominant clinical feature. This review briefly describes diagnostic methods and phenotypic characteristics of classic and atypical CF, as well as CFTR-related diseases, conditions in which mutated CFTR may contribute to the pathogenesis but do not strictly fit established diagnostic criteria.     

Methacholine reactivity and asthma

Methacholine tests were used in an epidemiologic study of the prevalence of asthma and chronic bronchitis in northern Sweden. Of 6610 subjects in three age groups from eight representative geographic areas in the northernmost province of Sweden, 5698 (86%) completed a postal questionnaire on respiratory symptoms, and 1506 underwent a structured interview and a lung function test. A total of 292 (5%) were diagnosed as having asthma. A subsample of 284 subjects (of 320 invited) classified at the interview as having asthma ( n = 98) or as having respiratory symptoms that might be due to asthma but not fulfilling the interview criteria for the diagnosis of asthma ( n = 186) underwent a methacholine test. Subjects who, before the interview study, already had a well-defined asthma diagnosis were not invited to the methacholine testing. Of those 98 subjects classified as having asthma, 61 % reacted to methacholine doses ≤ 4 mg/ml and 79% to doses ≤ 8 mg/ml, while the corresponding figures in the symptomatic but nonasthma group were 20% and 34%, respectively. The results show that a carefully performed structured interview accurately diagnoses asthma in epidemiologic studies. The methacholine tests provide important diagnostic information primarily in subjects in whom the medical history is equivocal.     

Foam-stability test on gastric aspirate and the diagnosis of respiratory-distress syndrome.

Gastric aspirate, collected from 79 infants within 30 minutes of birth, was subjected to the foam-stability test. The lecithin/sphingomyelin ratio was determined in 27. The results were compared with the incidence of respiratory-distress syndrome as determined independently by different investigators. Of the 59 infants with a positive foam-stability test on gastric aspirate, three had transient respiratory distress, and one the respiratory-distress syndrome; 17 of 22 had lecithin/sphingomyelin ratios greater than 2.0. Of nine infants who had intermediate test results, three were normal, four had transient respiratory distress, and two had the respiratory-distress syndrome. In all the 11 infants with negative foam-stability tests the respiratory-distress syndrome developed. The three gastric aspirates tested in this group had lecithin/sphingomyelin ratios of less than 1.5. These data indicate that the foam-stability test on gastric aspirate is a reliable index of fetal lung maturity in infants whose amniotic fluid is not available.     

Pertinence of the 2000 WHO criteria in non-immune children with severe malaria in Dakar, Senegal

The relevance of World Health Organization (WHO) criteria for severe malaria has not been assessed in non-immune children. The objectives of this study were (i) to evaluate the significance of 1990 WHO definition reconsidered in 2000 on distribution and lethality of severe cases in children admitted with falciparum malaria, and (ii) to contribute to the study of relevance of the WHO severe criteria in Dakar, an hypoendemic area in Senegal. PATIENTS AND METHODS: The 1990 WHO criteria, respiratory distress and platelet counts were prospectively collected in 1997-99 from children admitted to H?pital Principal de Dakar, Senegal, with falciparum malaria diagnosed on a thick blood film. This method allowed also the definition of severe cases according to 2000 WHO criteria. RESULTS: Among 311 patients (median age: 8 years old), according to the 2000 WHO criteria, the frequency of severe malaria cases was increased by 23% (75% versus 52%) and case-fatality rates thereof were decreased by 5% (17% versus 12%) compared with 1990 WHO definition. One death occurred among cases defined as severe on admission only according to criteria modified by WHO in 2000. A multivariate logistic regression model identified several independent prognostic factors: cerebral malaria, hypoglycaemia, respiratory distress, renal failure, collapse, abnormal bleedings, pupillary abnormalities and thrombocytopaenia defined as a platelet count below 100,000/mm3. A significant association (p < 0.001) was observed between platelet count increase and consciousness level improvement, evaluated on day of first platelet count control (time from admission: 1-7 d). Among survivors, a lesser improvement in coma score was associated with a decrease in platelet counts (p < 0.04). CONCLUSIONS: The 1990 WHO criteria, which predicted death among malaria cases in children living under stable falciparum transmission, are relevant in this series of non-immune children living in a low and seasonal transmission. Nevertheless new WHO criteria showed poor prognostic significance. However, the 2000 WHO definition was highly sensitive to detect severe malaria cases. These findings should be considered for managing severe malaria in migrant children.     

The differential diagnosis of testicular germ cell tumors in theory and practice

Summary To better appreciate the conflicts and controversy surrounding the classification of testicular tumors, and to reappraise their morphologic substrate under the advent of tumor markers, 389 of our own cases are reviewed, classified according to the systems advocated by the World Health Organization (WHO) and the Testicular Tumour Panel and Registry (TTPR) of Great Britain, and evaluated statistically.While many cases fit easily into either classification, the following difficulties were manifest: 1) Discrepancies in definitions and diagnostic criteria are the reason that considerably more germ cell tumors could be classified as mixed choriocarcinomas (WHO) than as trophoblastic teratomas (TTPR). It was found that tumor markers supply histochemical data that often conflict with rather than supplement morphologic ones in diagnosis and differential diagnosis. Similarly, the incidence of yolk sac structures, as yet not recorded separately by the TTPR, varies as either morphologic or histochemical criteria are applied. 2) The division of the morphologic spectrum of teratomatous differentiation by criteria of distinction that are unequal in the two systems yield comparable but non-congruent tumor entities. Consequently, borderline cases may undergo shifts to noncorresponding groups as they are translated from one system to the other. 3) Criteria separating teratoma with malignant transformation and polyembryoma (WHO) from closely allied lesions proved impractical. 4) Diagnostic labels that incorporate not only a morphologic pattern but a definite level in the histogenetic hierarchy generate a climate of incompatibility between systems whose histogenetic perspectives differ. Embryonal carcinoma's claim to totipotence, in particular, leads to a conceptual split with the teratomas and brings the WHO system by itself into theoretic difficulties. Moreover, as the morphologic criteria for embryonal carcinoma are not in keeping with its histogenetic premise, the rigid separation is difficult to enforce in practice.Once the air is cleared, a resolution is easily reached. In the combined use of both classifications their real difference, splitting vs lumping, becomes a true asset.The cooperation of our documentation group PADOK is gratefully acknowledged     

Delusional disorder–jealous type: how inclusive are the DSM–IV diagnostic criteria?

Delusional disorder-jealous type is a new diagnostic category in the Diagnostic and Statistical Manual for Disorders, Fourth Edition, Text Revision (DSM-IV-TR; American Psychiatric Association, 2000) in which delusions concerning a partner's infidelity must be present. Therefore, patients who experience a jealousy disorder, but do not experience delusions will not fit the diagnostic criteria. Using a database of 398 case histories of jealousy disorders reported in the literature from 1940-2002, we examined the percentage of these cases that met the diagnostic criteria for delusional disorder-jealous type. Only 4% of the cases met all diagnostic criteria. This is the first systematic comparison of the prevalence of these disorders. The results provide evidence that the diagnostic criteria are not inclusive, as most individuals suffering with a jealousy disorder were excluded from the diagnosis.     

Reduction in intraventricular hemorrhage by elimination of fluctuating cerebral blood-flow velocity in preterm infants with respiratory distress syndrome

In a previous study of preterm infants requiring mechanical ventilation for the respiratory distress syndrome, we demonstrated a striking association of fluctuating cerebral blood-flow velocity in the first day of life with the subsequent occurrence of intraventricular hemorrhage. Because this fluctuating pattern could be eliminated by muscle paralysis, we conducted a prospective study of preterm infants receiving mechanical ventilation for the respiratory distress syndrome in which we evaluated the effect of paralysis and this flow-velocity pattern on the incidence and severity of intraventricular hemorrhage. Twenty-four infants with the fluctuating pattern in the first hours of life were identified and randomly selected to serve as controls (10) or to be subjected to muscle paralysis (14). Intraventricular hemorrhage developed in all 10 control infants but in only 5 of the 14 infants subjected to muscle paralysis. Moreover, in 4 of the 5 paralyzed infants in whom hemorrhage developed, it did so after cessation of the paralysis. Seven of the 10 control infants had Grade III hemorrhage, the most severe variety of intraventricular hemorrhage, whereas none of the paralyzed infants had Grade III hemorrhage. We conclude that elimination of fluctuating cerebral blood-flow velocity in preterm infants with respiratory distress syndrome markedly reduces the incidence and severity of intraventricular hemorrhage.     

A direct comparison between lamellar body counts and fluorescent polarization methods for predicting respiratory distress syndrome

Our objective was to directly compare the diagnostic usefulness of lamellar body counting (LBC) and the TDx-FLM II assay (Abbott Laboratories, Abbott Park, IL) for predicting respiratory distress syndrome (RDS). This was a 5-year, retrospective, cohort study. A diagnosis of RDS was given to infants who received surfactant treatment and/or required ventilator support and/or continuous positive airway pressure for more than 24 hours. There were 172 infants without RDS and 12 with RDS included in the study. By using a TDx-FLM II cutoff of 55 mg/g or more for maturity, the sensitivity was 83%, specificity was 65%, predictive value of a mature result was 98%, and predictive value of an immature result was 14%. These results were similar to LBC using a cutoff of 50,000/microL or more with sensitivity of 92%, a specificity of 60%, a predictive value of a mature result of 99%, and a predictive value of an immature result of 14%. The LBC and TDx-FLM II methods have similar clinical usefulness.     

A decision support model to predict the presence of an acute infiltrate on chest radiograph

A chest infiltrate is needed to make a diagnosis of community-acquired pneumonia, but chest X-rays might be time consuming, entail radiation exposure, and demand resources that are not always available. We sought to derive a model to predict whether a patient will have an infiltrate on chest X-ray (CXR). This prospective observational study included patients visiting the Emergency Department of Beilinson Hospital in the years 2003–2004 (derivation cohort) and 2010–2011 (validation cohort), who had undergone a CXR, and were suspected of having a respiratory infection. We excluded all patients with possible healthcare associated infections. A logistic regression model was derived and applied to the validation cohort. A total of 1,555 patients met inclusion criteria: 993 in the derivation cohort and 562 in the validation cohort with 287 (29%) and 226 (40%) having an infiltrate, respectively. The derivation model area-under-the curve (AUC) was 0.79 (95% CI 0.76–0.82). We categorized the patients into three groups—presence or absence of infiltrate, or undetermined. In the validation cohort, 70 (12%) patients were classified as ‘no infiltrate’; 3 (4%) of them had an infiltrate, 367 (65%) were classified as ‘infiltrate’; 190 (52%) of them had an infiltrate on CXR, and 125 (46%) were classified as ‘undetermined’; 33 (26%) of them with an infiltrate on CXR. Using this prediction model for the evaluation of patients with suspected respiratory infection in an ED setting may help avoid over 10% of CXRs.     

Subependymal and Intraventricular Hemorrhages in the Newborn

The pathogenesis of intraventricular hemorrhage in the newborn includes that of subependymal hemorrhage (SEH), the single most common pathologic alteration seen in the brains of 417 consecutively autopsied infants. A clearly recognizable relationship of SEH to gestational age and clinical status exists in that all SEH occur in premature infants under 2500 g birthweight (although only 56% of all premature infants have SEH) and 95% of SEH occur in infants with the respiratory distress syndrome (although only 60% of infants with the respiratory distress syndrome have SEH). The pathogenesis appears to involve a combination of hypoxia, metabolic acidosis, venous stasis and rupture of the thin-walled veins so prominent in the germinal matrix.     

Intrathoracic cystic hygroma with sudden respiratory distress mimicking pneumonia

Benign cystic lesions such as cystic hygroma commonly manifest as progressively increasing swelling in the neck with or without compression effects. Rarely, they present with sudden respiratory distress in instances such as infection or haematoma resulting in a sudden increase in the size of the tumour. We present a seven month old child with sudden onset respiratory distress without any obvious neck swelling. The chest X ray findings correlated with the history and were suggestive of right upper lobe pneumonia that leads to a wrong diagnosis of aspiration pneumonia. However, presence of a deviated trachea in the neck raised a suspicion of possible mass. Computed tomogram showed a large cystic mass in the right upper mediastinum with tracheal collapse. We caution intensivists and paediatricians that sudden respiratory distress in infants in the absence of obvious neck swelling does not rule out possibility of intrathoracic tumour.     

Clinicopathological studies on pulmonary hypoplasia in very low birth weight infants

Seven VLBW infants with pulmonary hypoplasia (P.H.) were studied retrospectively and their necropsied lungs were analyzed morphologically and histometrically in an attempt to establish the clinical and pathological criteria of P.H. Clinically they had various features as follows; 1) causes with oligohydramnios due to amniotic fluid leakage, 2) bell-shaped chest and/or small lung radiographically, 3) severe respiratory distress immediately after birth, 4) frequent complications with air leaks, lethal within several hours after birth. Pathologically they showed a series of changes; 1) remarkably decreased LW: BW ratios, less than 0.015, 2) decreased number of alveoli per alveolar duct, less than 3 or 4 alveoli/duct compared with 6.5 of normal controls at 28 weeks' gestation, 3) immature duct system and increased interstitium which suggested delay in growth and structural maturation of the lungs. It is suggested that the tendency to develop pulmonary air leaks is not only due to high pressure ventilation but also to histological immaturity of the lungs.     

CLINICOPATHOLOGICAL STUDIES ON PULMONARY HYPOPLASIA IN VERY LOW BIRTH WEIGHT INFANTS

Seven VLBW infants with pulmonary hypoplasia (P.H.) were studied retrospectively and their necropsied lungs were analyzed morphologically and histometrically in an attempt to entablish the clinical and pathological criteria of P.H. Clinically they had various features as follows; 1) causes with oligohydramnios due to amniotic fluid leakage, 2) bell-shaped chest and/or small lung radiographically, 3) severe respiratory distress Immediately after birth, 4) frequent complications with air leaks, lethal within several hours after birth. Pathologically they showed a series of changes; 1) remarkably decreased LW: BW ratios, less than 0.015, 2) decreased number of alveoli per alveolar duct, less than 3 or 4 alveoli/duct compared with 6.5 of normal controls at 28 weeks' gestation, 3) immature duct system and increased interstitium which suggested delay in growth and structural maturation of the lungs. It is suggested that the tendency to develop pulmonary air leaks is not only due to high pressure ventilation but also to histological immaturity of the lungs.     

Morphological criteria of the malignancy of pheochromocytoma

Morphological features of the chromaffin tissue tumours removed surgically were studied in detail. The complex of the histological and cytological signs characterizing morphological criteria of the pheochromocytoma malignancy is recommended to be used in the everyday diagnostic practice. It is suggested that pheochromocytomas should be divided into the three main variants which seem to be stages of the neoplastic process: so-called benign, borderline malignant, and malignant tumours. The latter may be metastasizing or without visible metastasis but having all the features of morphological malignancy identical to those in the metastasizing neoplasms. The group of the borderline malignant pheochromocytoma is of importance not only theoretically but practically as well, since it complements our concepts of the neoplastic process dynamics and in many cases may be the indication of the possible prognosis of the disease.