Marta C. Cohen

Less Invasive Autopsy: Benefits and Limitations of the Use of Magnetic Resonance Imaging in the Perinatal Postmortem

The decline in the postmortem (PM) autopsy rate in the United Kingdom paralleled the change in public perception of this procedure after the organ retention crisis in 2000. The introduction of magnetic resonance imaging (MRI) in the fetal, perinatal, and pediatric autopsy led some investigators to propose that MRI could replace the conventional PM. We assessed the role of MRI in fetal autopsy as an addition or a potential replacement method to the conventional PM and to evaluate the benefits and limitations of each technique. We retrospectively reviewed the PM and MRI examination of 100 fetuses. The MRI was limited to the brain or brain and spinal cord. Forty-six cases involved termination of pregnancy; 30 were intrauterine fetal deaths/stillbirths; 16 were premature deliveries followed by neonatal death; and 8 were miscarriages. The mean gestational age of all cases was 25.54 weeks (range: 13–41 weeks). In 54 of the 90 full PMs, there was a complete agreement between the MRI and autopsy findings on the morphology of the brain and spine. Despite this agreement, the information gained at the PM was relevant to find the cause or mechanism of death in 20 of 54 cases (37%). In 24 autopsies the MRI added valuable information to the autopsy. However, if MRI had been the only investigation, essential information would have been lost in 17 of 24 cases (71%). In 12 cases the PM was clearly superior to the MRI. The integrated result obtained from the traditional autopsy remains crucial in determining the cause or mechanism of the malformation or of the fetal/perinatal death and accordingly is important for the counseling offered to parents regarding the recurrence risk for future pregnancies.

Diagnostic accuracy of post-mortem magnetic resonance imaging in fetuses, children and adults: A systematic review

To determine, in a systematic review, the diagnostic accuracy, acceptability and cost-effectiveness of less invasive autopsy by post-mortem MR imaging, in fetuses, children and adults. We searched Medline, Embase, the Cochrane library and reference lists to identify all studies comparing post-mortem MR imaging with conventional autopsy, published between January 1990 and March 2009. 539 abstracts were identified; 15 papers met the inclusion criteria; data from 9 studies were extracted (total: 146 fetuses, 11 children and 24 adults). In accurately identifying the final cause of death or most clinically significant abnormality, post-mortem MR imaging had a sensitivity and specificity of 69% (95% CI-56%, 80%) and 95% (95% CI-88%, 98%) in fetuses, and 28% (95% CI-13%, 47%) and 64% (95% CI-23%, 94%) in children and adults, respectively; however the published data is limited to small, heterogenous and poorly designed studies. Insufficient data is available on acceptability and economic evaluation of post-mortem MR imaging. Well designed, large, prospective studies are required to evaluate the accuracy of post-mortem MR imaging, before it can be offered as a clinical tool.

Evidence of Occurrence of Intradural and Subdural Hemorrhage in the Perinatal and Neonatal Period in the Context of Hypoxic Ischemic Encephalopathy: An Observational Study from Two Referral Institutions in the United Kingdom

The occurrence of subdural hemorrhage (SDH) on the convexities of the cerebral hemispheres is not an unusual finding in the setting of intrauterine, perinatal, or neonatal deaths, the hemorrhage usually presenting either as a thin film over the occipital poles or as a small infratentorial bleed. Working in 2 referral centers with over 30 000 deliveries per year, we routinely examine the dura macroscopically and histologically in nonmacerated fetuses over 24 weeks in gestation and in neonates. This paper describes our experience of intradural hemorrhage (IDH) and SDH associated with hypoxia. Our series comprises 25 fetuses and 30 neonates with obvious macroscopic intradural hemorrhage and hypoxia of varying degrees of severity diagnosed by systematic examination of the brain. Fetal gestational age ranged from 26–41/40 weeks (all no more than 24 hours from intrauterine death), while the 30 neonates lived for between 1 hour and 19 days. Simultaneously with IDH, frank SDH was seen in 2 of 3 of all cases (16 fetuses and 20 neonates). Intradural hemorrhage was more prominent in the posterior falx and tentorium, most likely because of the existence of 2 venous plexus at these sites. Our findings demonstrate that SDH and cerebral hypoxia are common associations of IDH and that SDH (often seen as a thin film of hemorrhage) almost always occurs in association with diffuse falcine IDH. Diffuse IDH with SDH are more frequently associated with severe or moderate hypoxic ischemic encephalopathy (HIE), while mild or early HIE is more common with focal IDH without SDH.

Fulminant pertussis: a multi-center study with new insights into the clinico-pathological mechanisms.

Pertussis carries a high risk of mortality in very young infants. The mechanism of refractory cardio‐respiratory failure is complex and not clearly delineated. We aimed to examine the clinico‐pathological features and suggest how they may be related to outcome, by multi‐center review of clinical records and post‐mortem findings of 10 patients with fulminant pertussis (FP). All cases were less than 8 weeks of age, and required ventilation for worsening respiratory symptoms and inotropic support for severe hemodynamic compromise. All died or underwent extra corporeal membrane oxygenation (ECMO) within 1 week. All had increased leukocyte counts (from 54 to 132 × 109/L) with prominent neutrophilia in 9/10. The post‐mortem demonstrated necrotizing bronchitis and bronchiolitis with extensive areas of necrosis of the alveolar epithelium. Hyaline membranes were present in those cases with viral co‐infection. Pulmonary blood vessels were filled with leukocytes without well‐organized thrombi. Immunodepletion of the thymus, spleen, and lymph nodes was a common feature. Other organisms were isolated as follows; 2/10 cases Para influenza type 3, 2/10 Moraxella catarrhalis, 1/10 each with respiratory syncytial virus (RSV), a coliform organism, methicillin‐resistant Staphylococcus aureus (MRSA), Haemophilus influenzae, Stenotrophomonas maltophilia, methicillin‐sensitive Staphylococcus aureus (MSSA), and candida tropicalis. We postulate that severe hypoxemia and intractable cardiac failure may be due to the effects of pertussis toxin, necrotizing bronchiolitis, extensive damage to the alveolar epithelium, tenacious airway secretions, and possibly leukostasis with activation of the immunological cascade, all contributing to increased pulmonary vascular resistance. Cellular apoptosis appeared to underlay much of these changes. The secondary immuno‐compromise may facilitate co‐infection. Pediatr Pulmonol. 2009; 44:970–980. ©2009 Wiley‐Liss, Inc.

Contribution of bacteriology and virology in sudden unexpected death in infancy

Objective To appraise the inter-agency protocol used in sudden unexpected death in infancy (SUDI) cases in South Yorkshire, UK. Design A retrospective audit of 121 postmortems carried out over a 3-year period was completed to assess adherence to local guidelines introduced in 2005 specifying the required microbiological specimen set to be collected at postmortem in cases of SUDI. Data on organisms isolated was also collated and assessed for significance. Setting Sheffield Childrens Hospital Histopathology Department is the South Yorkshire referral centre for SUDI. Post-mortem samples were processed by Sheffield Teaching Hospitals microbiology and virology departments. Patients All postmortems of SUDI in children less than 2 years of age performed between January 2004 and December 2007. Results 116/121 cases had samples sent for microbiological and/or virological investigation: 90% of cases had a blood culture and 68% had a cerebrospinal fluid sample taken. Of the 116 cases, 49% had a potentially pathogenic organism isolated, 73% had post-mortem flora and 10% had no organisms isolated (32% had both post-mortem flora and a potential pathogen). 27% of cases were found to have middle ear exudate requiring sampling, from 48% of which a potentially pathogenic organism was isolated. Conclusions Our finding of a potential pathogen in 57/116 (49%) of our cases, although not necessarily the cause of death, confirms the relevance of performing multisite and virology investigations in all cases of SUDI. Standardised protocols with agreed definitions are necessary for a consistent approach.

Role of confocal endomicroscopy in the diagnosis of celiac disease.

Background and Aims: Confocal laser endomicroscopy (CLE) is a recent development that enables surface and subsurface imaging of living cells in vivo at 1000× magnification. The aims of the present study were to define confocal features of celiac disease (CD) and to evaluate the usefulness of the CLE in the diagnosis of CD in children in comparison to histology. Patients and Methods: Nine patients (8 girls) with a median age of 8.35 years (range 2–12.66 years) and a median weight of 28.3 kg (range 11–71 kg) were suspected with CD and 10 matched controls underwent oesophagogastroduodenoscopy using the confocal laser endomicroscope (EC3870CILK; Pentax, Tokyo, Japan). Histologic sections were compared with the confocal images of the same site by 2 experienced paediatric histopathologists and endoscopists, all of whom were blinded to the diagnosis. Results: The median procedure time was 17 minutes (range 8–25 minutes). Confocal features of CD were defined and a score was developed. A total of 1384 confocal images were collected from 9 patients and 10 controls. Five images from each patient and control were selected and compared with the biopsy specimen of the same site. The sensitivity, specificity, and positive predictive value for the confocal images in comparison to the histology were 100%, 80%, and 81%. The kappa inter-observer agreement between the 2 endoscopists was 0.769 (P = 0.018) and between the 2 histopathologists was 0.571 (P = 0.05). Conclusions: Confocal endomicroscopy offers the prospect of diagnosis of CD during ongoing endoscopy. It also enables targeting biopsies to abnormal mucosa and thereby increasing the diagnostic yield, especially when villous atrophy is patchy in the duodenum.

Utility of Post-Mortem Genetic Testing in Cases of Sudden Arrhythmic Death Syndrome

Background Sudden arrhythmic death syndrome (SADS) describes a sudden death with negative autopsy and toxicological analysis. Cardiac genetic disease is a likely etiology. Objectives This study investigated the clinical utility and combined yield of post-mortem genetic testing (molecular autopsy) in cases of SADS and comprehensive clinical evaluation of surviving relatives. Methods We evaluated 302 expertly validated SADS cases with suitable DNA (median age: 24 years; 65% males) who underwent next-generation sequencing using an extended panel of 77 primary electrical disorder and cardiomyopathy genes. Pathogenic and likely pathogenic variants were classified using American College of Medical Genetics (ACMG) consensus guidelines. The yield of combined molecular autopsy and clinical evaluation in 82 surviving families was evaluated. A gene-level rare variant association analysis was conducted in SADS cases versus controls. Results A clinically actionable pathogenic or likely pathogenic variant was identified in 40 of 302 cases (13%). The main etiologies established were catecholaminergic polymorphic ventricular tachycardia and long QT syndrome (17 [6%] and 11 [4%], respectively). Gene-based rare variants association analysis showed enrichment of rare predicted deleterious variants in RYR2 (p = 5 × 10-5). Combining molecular autopsy with clinical evaluation in surviving families increased diagnostic yield from 26% to 39%. Conclusions Molecular autopsy for electrical disorder and cardiomyopathy genes, using ACMG guidelines for variant classification, identified a modest but realistic yield in SADS. Our data highlighted the predominant role of catecholaminergic polymorphic ventricular tachycardia and long QT syndrome, especially the RYR2 gene, as well as the minimal yield from other genes. Furthermore, we showed the enhanced utility of combined clinical and genetic evaluation.

Solitary, multifocal and generalized myofibromas: clinicopathological and immunohistochemical features of 114 cases.

Oudijk L, den Bakker M A, Hop W C J, Cohen M, Charles A K, Alaggio R, Coffin C M & de Krijger R R

Malignant Ectomesenchymoma in Childhood

Five childhood malignant ectomesenchymomas are reported from three centers in three countries. The children were all younger than 3 years (four less than 12 months), four were boys, and four tumors were sited in the pelvis or external genitalia. All tumors had distinctive light microscopic features of rhabdomyosarcoma and three also demonstrated small numbers of included neuronal cells. Immunohistochemical studies and transmission electron microscopy revealed the additional presence of neurogenic components in the remaining two patients. An additional epithelial component was found by immunohistochemistry in one tumor, which suggests a pluripotential origin that still requires karyotypic investigation. Aggressive chemotherapy and adequate surgical excision have thus far been effective in providing disease-free follow-up for periods of 7 to 50 months. It is implied that because the biological behavior and morphology closely resemble those of rhabdomyosarcoma and because the neurogenic component is often inconspicuous, many malignant ectomesenchymomas may be misdiagnosed as rhabdomyosarcomas.

Vitamin D Deficiency and Sudden Unexpected Death in Infancy and Childhood: A Cohort Study

We sought to (1) determine if there is an increased prevalence of vitamin D deficiency (VDD) in cases of sudden death in infancy and childhood; (2) establish whether there is a link between VDD and infection; and (3) assess if the level of vitamin D can be related to abnormalities in the skeletal survey and rib histology in our cohort. The postmortem reports of cases in which vitamin D levels were measured in 2009 and 2010 were retrieved. When parental consent for audit had been granted, rib histology and skeletal surveys were reviewed. Plasma 25-hydroxyvitamin D levels were measured in 41 postmortem cases. Ten (24.5%) had adequate levels, 5 (12%) had suboptimal levels, 16 (39%) had moderate deficiency, and 10 (24.5%) had severe deficiency. We had only 4 cases with VDD and infection. There were 25 cases of unexplained death in our cohort, and 76% of these had inadequate vitamin D levels. The rib histology was abnormal in 69% of cases that had inadequate vitamin D levels, while the radiology was abnormal in 19% of cases. A significant proportion of infants and children who died suddenly and unexpectedly had inadequate levels of vitamin D. We were unable to confirm or exclude an association between VDD and infection due to the small number of cases with confirmed infection. Further multicenter studies are needed to confirm our findings and explore possible associations between VDD and other known risk factors for sudden unexplaineddeath in infancy and childhood.