ECP 2022 Abstract Book

Virchows Archiv (2022) 481 (Suppl 1):S1–S364 13 h-caldesmon. EBER-ISH was positive in both components and EBV-SMT was diagnosed. Immunosuppressants were withdrawn and the masses were surgically debulked. Conclusion: EBV-SMT is rare in children with solid organ transplant. The differential diagnoses were spindle cell rhabdomyosarcoma, synovial sarcoma and solitary fibrous tumour. The myoid nature of the spindle cells, the second population of primitive round cells and the clinical history were helpful to prompt investigations for EBV. It can be diagnostically challenging if only the primitive round cell component is sampled, and it should be considered in the work up for small round blue cell tumours in immunosuppressed children. E-PS-20-003 Tuberous sclerosis complex: case report and literature review M. Garcia Martos*, C.M. Vieru, Y. Gómez Navarro *Hospital General Universitario Gregorio Marañón, Spain Background & objectives: Tuberous Sclerosis Complex (TSC) is a rare autosomal dominant, multisystem disorder that is characterized by cellular and tissue dysplasia in several organs. The clinical manifesta- tions are result of a mutation of one of two suppressor genes TSC1 and TSC2. Methods: We present a 34 weeks foetus with multiples cardiac rhabdomyomas found in the 33rd week ultrasound routine. Consequently, a foetal nuclear magnetic resonance was conducted, showing brain surface, subependymal nodules in thalamus-striated sulcus, cortical tubers and linear lesions in deep white matter. The case met three major criteria for sclerosis tuberous and concluded with the pregnancy’s termination. Results: The autopsy results revealed subependymal lesions com- posed of vacuolated cells with abundant eosinophilic cytoplasm, and few binucleated and dyscrete atypia. Moreover, pseudonodular agrupations of dysmorphic neuronal cells were found in the sub- cortical cortex. The heart presented small tumour nodules in both ventricles, formed histologically of large polygonal cells with gly- cogen vacuoles, central nucleus and cross striations of cytoplasm radiating from the nucleus to the cell membrane. These findings led to diagnosing subependymal giant cell neoplasia, cortical tubers, cardiac rhabdomyoma and multiple renal cysts, compatible with the clinical diagnosis of tuberous sclerosis. In consequence, a genetic study was performed and detected a TSC2 mutation, c22251 C>T, p- Arg751*. Conclusion: TSC is an uncommon syndrome characterized by formation of hamartomas in multiple organs, which incidence has been estimated in 1/6000-1/10000 newborns annually. It presents a wide range of clinical and phenotypic manifestations with varying severity. The brain, heart and kidney are commonly involved in this syndrome. Most of cases, are caused by a de novo mutation or are the effect of parental gonadal mosaicism. A thorough clinical evaluation should be followed by genetic testing for confirmation of TSC and prognostication. E-PS-20-004 Clinical and morphological correlations during pregnancy in conditions of circulatory hypoxia O. Reshetnikova*, L. Rudiuk *Immanuel Kant Baltic Federal University, Russia Background & objectives: Congenital heart disease (CHD) during pregnancy in women leads to severe hemodynamic disorders. We aimed to study the clinical and morphological correlations between maternal hemodynamics during 30-34 weeks and structural remodel- ling of chorionic villi in placentas in women with CHD Methods: Thirty-five medical records of pregnancies were ana- lysed with emphasis on the mother’s heart rate (HR),blood pressure (BP); systolic and minute blood volumes (respectively: SBV and MBV). Respective placentas studied included 20 cases of CHD and 15 controls (non-complicated pregnancies). H&E slides, were studied microscopically and by point count computer morphom- etry.The differences between groups’ data were elucidated by non- parametric Mann-Whitney test. Results: The results of the study showed a decrease in maternal hemodynamic parameters: HR, BP, SBV and MBV in the period of 30-34 weeks of gestation during pregnancy with CHD compared with the control (p<0.05). Microscopic examination, in the contrast to physiological pregnancy, revealed an increase in syncytiocapil- lary membranes (SCM) and their thickening compared to the con- trol. The analysis of correlations between the thickness of the SCM and the SBV and the MBV of maternal hemodynamics established the presence of negative linear connections during 30-34 weeks of gestation in the central parts of the placenta (respectively: r= -0.6635 and r= -0.6400). Conclusion: Deficiency of maternal hemodynamics during 30-34 weeks of gestation is accompanied by increased sclerotic processes in the placenta in women with CHD. As a result, the permeability of the SCM decreases, the metabolic processes between mother and foetus worsen. Remodeling of the SCM structure is considered in the aspect of adaptation of the placenta to circulatory hypoxia due to hemodynamic disorders in women with CHD. E-PS-20-005 Neonatal kidney as a rare site of extramedullary haematopoiesis M. Jovanovic*, G. Nikolić, T. Terzic, S. Glumac *University of Belgrade, Medical Faculty, Institute for Pathology, Serbia Background & objectives: Extramedullary haematopoiesis (EMH) presents development of hematopoietic tissue outside the red bone mar- row. During foetal and early neonatal life, the major sites of EMH are liver and spleen. If needed, EMH appears in other organs like adrenals, and perirenal fatt. Methods: Histological and immunohistochemical analysis of EMH focuses in postmortem samples of neonatal kidneys. Results: We present an autopsy case of a twin, preterm, hypotrophic male neonate who was born in 32. gestational week and died 2 days after the labor due to neonatal respiratory distress syndrome. During pregnancy, a twin-to-twin transfusion syndrome was diagnosed, while after the labor marked congenital anaemia was detected. The major gross findings were: pailor, anaemia of internal organs, bilateral calcified cysts of periventricular white matter, hydropericardium, neonatal ARDS. An interesting histopathological findings in kidney samples were patchy interstitial infiltrates of uniform cells, with increased N/C ratio, which immunohistochemically correspond to erythroblasts (CD71+), while immunoexpresion of other markers was absent (CD34, CD117, TdT, Pax5, CD19, Lysosim, CD38, CD10, CD20, CD61). Conclusion: Foetal and neonatal hypoxia, caused by numerous aetiologies, induce EMH in other various internal organs. Unlike in adults, kidney in foetuses and neonates is an extremely rare site of EMH, especially in isolated one-lineage hyperplasia. This finding could help further research in the field of potential sites of EMH. E-PS-20-006 Foetal arthrogryposis in twin gestation: case report and lit- erature review S323