ECP 2023 Abstracts

S332 Virchows Archiv (2023) 483 (Suppl 1):S1–S391 13 In our sample, 9,8% were SCST, 2/8 were eligible for neoadjuvant treatment. Currently, all are alive, disease-free, and without recurrence or progression reported. Our data do not show significant differences from those reported in literature. A large sample is needed because of the rarity of these neoplasms. E-PS-19-011 Investigating the presence of microplastics and additives on compli- cated pregnancy: a study of human amniotic fluids and placentas P. Delongová*, P. Hurník, J. Škarda, J. Halfar, K. Čabanova, K. Vávra, R. Špaček, O. Šimetka *Institute of Pathology and Molecular Genetics, University Hospital of Ostrava, Czech Republic Background & objectives: Recently it was demonstrated by numerous studies that microplastics are almost ubiquitous in various environ- ments. Thus, exposure of pregnant women to microplastics poses a possible risk to the unborn child. Methods: All women involved in this study had physiological, single- ton pregnancies complicated with preterm prelabour rupture of mem- branes (PPROM). 20 samples of amniotic fluid and placenta from 10 patients were analysed for the presence of microplastics and plastic additives by Fourier transform infrared spectroscopy - attenuated total reflectance (FTIR–ATR) after alkaline digestion with KOH. Results: 9 of 10 patients were found to have microplastics or additives in amniotic fluid, placenta, or both. The most represented materials were Chlorinated Polyethylene (CPE) and Calcium zinc PVC Stabilizer. Conclusion: This study presents the first evidence of the simultaneous presence of microplastics and additives in amniotic fluid and placentas. Funding: 16/RVO-FNOs/2021 E-PS-19-014 Two true knots in umbilical cord: a report of two cases with differ- ent pathological findings and clinical implications C. Gouta*, S. Angelidou, D. Dalakoura, E. Demertzidou, E. Hanioti, M. Paida, E. Ralli, E. Sakellariou, A. Kougioumtzidou, A. Sotiriadis *Department of Histopathology, Hippokration General Hospital of Thessaloniki, Greece Background & objectives: The incidence of a single true knot in umbilical cord ranges from 0,3 to 2% of all pregnancies. We report two cases of two true umbilical knots with completely different histo- pathological findings and clinical presentation. Methods: Case 1: A 30-year-old woman presented at the emergency department due to reduced foetal movements at 33w+3d of gestation. Intrauterine foetal demise was verified and a caesarean section was per- formed. Case 2: A 27-year-old woman was referred to our hospital with polyhydramnios at 35w+6d of gestation. After amniocentesis, a nonre- active NST was observed and led to an emergency caesarean section. Results: Case1: Macroscopic examination revealed the existence of two simple, tight true umbilical knots. The umbilical cord appeared hyper-coiled and exceeded in length the 90th percentile for the ges- tational age. Microscopically, the diagnosis of acute, sub-acute and chronic foetal vascular malperfusion was established and attributed to the umbilical cord obstruction. Case 2: Macroscopic examination showed the existence of two simple, loose true knots in umbilical cord. Additionally, a single umbilical artery was observed. Microscopic examination of the placental disc displayed no specific lesions but rather findings compatible with early adaptation to acute hypoxia. The two true umbilical knots were therefore considered to be an incidental finding. Conclusion: While the existence of a single true knot is encountered in the everyday practice, the occurrence of more than one umbilical knot is quite rare. To our knowledge, the exact prevalence of two true knots in general population has not been documented and only a short number of cases have been reported. Our case report contributes to the literature presenting two rare cases of two true umbilical knots with diverse predisposing factors, varying macroscopic and microscopic findings and clinical outcomes. E-PS-19-015 Vulvar botryoid variant of embryonal rhabdomyosarcoma in a 5 months old girl B. Malkoc*, B. Dogan Gun, E. Kaymaz, F. Kutlu, N. Yuksek, D. Bil- gili, B.H. Guvenc *Ardahan State Hospital Pathology Division, Turkey Background & objectives: Rhabdomyosarcoma (RMS) originates from primary mesenchymal cells that show skeletal muscle differentia- tion, being the third most common extracranial malignant solid tumour in children and adolescents. Genitourinary location compromise 20% of the primary site, but vulvar location is exceptional. Methods: We report a 5 months old girl presenting with vulvar mass in gross appearance of "grape bunches", initially recognized as small polypoid lesion during newborn period. Abdominal MR showed 4.5x2.6x2 cm sized, lobulated and well-demarcated vulvar lesion neighbouring left of urethral meatus. The resident mass was finally removed totally, successfully saving the urethral meatus, following initial incisional biopsy and chemotherapy. Results: Histopathologic evaluation of incisional biopsy material revealed focally ulcerated squamous epithelium, neighbouring hyper- cellular rhabdomyoblastic groups, as described cambium layer which is specific for Botryoid variant of Embryonal RMS. These atypi- cal cells had narrow cytoplasm, contained oval or spindle shaped hyperchromatic nuclei, no necrosis, significant mitotic activity and pleomorphism. Occasionally some of them had broad cytoplasm and rhabdoid morphology, the nucleus was located peripherally. Following successful chemotherapy and fertility-preserving surgery, pathologic evaluation showed cytodifferentiation due to chemotherapy and contained numerous maturating rhabdomyoblasts. Ki-67 prolifera- tion index was 2-3% and proximal surgical border was free of tumour. Currently the patient is in 2 years clinical follow-up without any com- plaints and progression. Conclusion: The Paediatric Oncology Group (POG) has declared the assessment of malignancy based on the histological type, presence and amount of the necrosis and mitotic activity. The recurrence rate of vaginal and cervical embryonal RMS is high (70%) in some case series. Thus, all types of RMS must be considered as high-grade sar- comas. New multidrug chemotherapy regimens with or without radia- tion therapy used in combination with less radical fertility-preserving surgery is promising in treatment with good results. E-PS-19-016 Management of an infected vesico-urachal diverticulum in a 12-year-old male B. Malkoc*, F. Kutlu, B.H. Guvenc, F. Sezer *Ardahan State Hospital Pathology Division, Turkey Background & objectives: The urachus is an embryonic remnant of the apical portion of the primitive bladder dome and changes into fibrous band during descendance into the pelvis. Vesico-urachal diver- ticulum is the rarest form of an incomplete obliteration and early diag- nosis is important. Methods: We report a 12-year-old male, complaining of generalized abdominal pain, with no umbilical discharge, diagnosed as infected urachal cyst under ultrasound. A vesico-urachal diverticulum as a focal outpouching at the vesical dome with a narrow opening was confirmed under VCUG and cystoscopic evaluation. The connection between the umbilicus was divided and the mass was totally resected through a Pfannenstiel incision.