ECP 2023 Abstracts

S331 Virchows Archiv (2023) 483 (Suppl 1):S1–S391 13 manifestations, usually with a benign course. The aim of this paper is to report a case of HHV-6 encephalitis with fulminant cerebral oedema. Methods: This is an autopsy case of a 5-month-old child who had pneumonia, requiring hospitalization. After the resolution of the condi- tion, he was discharged in good general condition without alterations in the physical examination. 2 days later, he got cough, runny nose and irritability in the 24 hours before his death. Results: At the autopsy examination, the brain had a soft consistency, with significant oedema, mainly in the grey matter and small foci of subarachnoid haemorrhage. CSF was collected and sent for laboratory analysis, in which HHV-6 was detected by means of PCR in the cer- ebrospinal fluid (CSF). Histopathological analysis of the brain tissue showed diffuse and intense cerebral oedema, in addition to lymphocytic inflammatory infiltrate in the meninges. Conclusion: HHV-6 is an uncommon cause of central nervous system infection, primarily affecting immunocompromised patients. In other reports, the febrile syndrome is frequent, associated with irritability or seizures, in addition to imaging findings compatible with diffuse cerebral oedema and CRP detected in the CSF. Although HHV-6 is a rare cause of encephalitis in children, it is important to consider it as a differential diagnosis in the presence of cerebral oedema, as HHV-6 can be lethal, even in immunocompetent children. E-PS-19-008 Waardenburg anophthalmia syndrome: case report and a review of the literature A.B. Çetinkaya*, M.B. Bereketoğlu, B.N. Ateş, S. Büyükkurt, S. Tuğ Bozdoğan, K. Erdogan *Department of Pathology, Faculty of Medicine, Cukurova University, Adana, Turkey Background & objectives: Waardenburg anophthalmia syndrome (WAS) is a rare autosomal recessive genetic disorder that is caused by SMOC1 gene mutation. Present case is an autopsy case of genetically proven WAS. Methods: Approximately 300,000 SNP markers were examined by SNP arrays with Human Cyto SNP-12 DNA Analysis Bead Chip v2.1 kit (Illumina, San Diego, California, USA). Blue Fuse Multi Software and Genome Studio Data Analysis Software v.2011.1 assisted to ana- lyse that were based on the reference human genome (hg19/GRCh37) and interpreted according to ISCA and ACMG guidelines. Results: The presenting case was a male foetus. The gestational age was 24 weeks, proven by second trimester ultrasound measurement. Physical examination showed microcephaly, agenesis of the 5th toe of both feet, tibial bowing, rocker bottom feet, left eye anophthalmia and right eye severe microphtalmia, antevert nose, microretrognathia, low set ears. The thoracal, and abdominal cavity examination revealed agenesis of right hemidiaphragm and horseshoe kidney. On radio- graphic examination, limb abnormalities such as hypoplastic and bow- ing tibia and fibula, hip dislocation and cleft vertebra were detected. SNP arrays showed, 203 kb homozygous deletion containing the entire SMOC1 gene as well as heterozygous 203 kb deletion in parents. Conclusion: This is the first case that the homozygous SMOC1 whole gene deletion was observed in the literature. Hemidiaphragm agenesis is the other unique finding that was not reported yet. In conclusion, Waardenburg Anophtalmia syndrome is a rare disorder that should be kept in mind in patients with anophthalmia and limb abnormalities. E-PS-19-009 Recurrent respiratory papillomatosis: a case of lung transplanta- tion as a therapeutic option A. Chaachou Charradi*, I. Sansano Valero, J. Camacho Soriano, M. Garrido Pontnou, C.E. Haro Haro, A. Navarro Jiménez *Vall d’Hebron University Hospital, Spain Background & objectives: Recurrent respiratory papillomato- sis (RRP) is a benign entity of the aerodigestive tract caused by human papillomavirus (HPV), mainly affecting children and young adults. Papillomas appear as exophytic nodules, mostly laryngeal, but occasionally in the nasopharynx, tracheobronchial tree and lung parenchyma. Methods: We reviewed the case of a 13-year-old patient transplanted bipulmonary due to chronic respiratory failure secondary to laryngeal papillomatosis with pulmonary dissemination. Results: Our patients was diagnosed at 3 months age, as the majority of infections occur at birth, during passage through the birth canal of infected mothers. Upon histopathological study of the lung explants, we identified a mul- tifocal proliferation of lesions composed of nested squamous cells with fibrovascular axis. These cells showed minimal atypia with prominent nucleoli, poorly demarcated eosinophilic cytoplasm and few mitotic figures. Its growth pattern was expansive, and no areas of invasion were identified. A polymerase chain reaction (PCR) test was performed on this tissue, yielding a positive result for HPV serotype 11, which, together with HPV-6, is responsible for most cases of RRP. Conclusion: Despite being a generally benign entity, RRP can pre- sent serious complications, especially with the pulmonary parenchyma involvement, even reaching malignant transformation. Its clinical manifestations are mainly respiratory and can end in respira- tory failure as in our case. Currently, no curative treatment has been developed and surgery remains the mainstay of treatment. Although bipulmonary transplan- tation is not described in the literature as a therapeutic option in RRP with lower airway involvement, we present the first case with good evolution so far. E-PS-19-010 Sex cord-stromal ovarian: a 10-year experience with paediatric ovarian tumours in a surgical pathology department from a ter- tiary Portuguese hospital C. Courelas*, A. Alves, J. Gama, J. Pimentel, V. Almeida, A. Lai, R. Almeida *Pathology Department, Coimbra Hospital and University Centre (CHUC), Portugal Background & objectives: Paediatric ovarian tumours are rare. Sex cord-stromal tumours (SCST) are even rarer, and diagnosis is challeng- ing due to their heterogeneous histologic features. This study aims to describe 10 years of experience diagnosing these tumours in a Portu- guese Surgical Pathology Department. Methods: We collected histopathological data from all paediatric ovar- ian tumours diagnosed in girls younger than 18-year-old, from 2012 to 2022, by the Surgical Pathology Department from Coimbra Hospital and University Centre. SCST were further analysed according to malig- nant potential, treatment, and follow-up information. Results: In the 10 years, 82 ovarian paediatric tumours were diag- nosed: 58,5% Germ cell tumours, 31.7% Epithelial tumours and 9.8% SCST. Over this period, the distribution was uneven - 2019/2020 showed a sharp decrease in cases, with a slow recovery since 2021. Age distribution ranged between 2-18 years old, mean 14±3.89 - 50% 15 years or older. Relating to SCST the sample included: fibroma (2/8), sclerosing stro- mal tumour (2/8), granulosa cell tumour (3/8) and Sertoli-Leydig cell tumour (1/8). Besides surgery, two patients were eligible for neoad- juvant chemotherapy. Currently, we have follow-up information on 6 patients, all disease-free, with no recurrence or progression history. Conclusion: In our department, about eight cases per year of paedi- atric ovarian tumours were diagnosed, with a marked decrease in the pandemic years. Germ cell tumours were the most frequent (58,5%).