ECP 2023 Abstracts

S336 Virchows Archiv (2023) 483 (Suppl 1):S1–S391 13 (Group 2), stained with hematoxylin/eosin and CD 34 immunostain were reviewed, the latter for clustered distal villi with endothelial fragmentation of recent foetal vascular malperfusion (FVM). Results: Caesarean delivery and ex utero intrapartum treatment were more common in Group 1, but Group 2 showed more statistically sig- nificantly increased other clinical phenotypes. Frequencies of large vessel (foetal vascular thrombi, stem vessel obliteration, intramu- ral fibrin deposition) and distal villous FVM (clustered endothelial fragmentation by CD34 immunostaining, stromal vascular karyor- rhexis, avascular, or mineralized villi) were not different between the groups, but low grade distal villous FVM was statistically sig- nificantly more common in Group 1 than in Group 2 (39% vs. 24%), while high grade distal villous FVM in Group 2 than Group 1 (18% vs. 6%), respectively. Recent distal segmental FVM by endothelial fragmentation was similarly frequent in both groups. Conclusion: Large vessel and distal villous FVM in both CDH and UC compression were overall qualitatively and quantitatively simi- lar, but several times more common than in general population. How- ever, CDH placentas showed more frequent low grade distal villous FVM and less frequent high grade distal villous FVM than those seen in UC compromise. FVM of CDH may be therefore caused by similar pathomechanism as that of UC compromise, with resulting impaired placental foetal blood outflow, but less severe. E-PS-19-028 Chronic histiocytic intervillositis with maternal cushing disease: a case report H.S. Toru*, D. Durna, C.Y. Sanhal, N. Yılmaz *Akdeniz University, Turkey Background & objectives: The pathological examination of the pla- centa is generally not of interest compared to other surgical pathology branches. However, a good understanding of placental pathologies can provide good obstetric care and evaluation in terms of recurrence risk in subsequent pregnancies. Methods: Chronic histiocytic intervillositis (CHI) is a pregnancy dis- order characterized by infiltration of maternal macrophages into the intervillous space of the human placenta, often with accompanying perivillous fibrin deposition. We want to highlight this interesting case to encourage further research on CHI. Results: C/S surgery was planned at 38 weeks for a 40-year-old female patient who was followed up for Cushing’s disease, who underwent IVF treatment. As a result of the endocrinology consultations, an oper- ation order was obtained with the “steroid umbrella” protocol. No signs of IUGR were found in the antenatal follow-ups. No abnormal find- ings were detected in Doppler artery indices and biophysical profiles. According to these data, it was reported with the diagnosis of Chronic histiocytic intervillositis Conclusion: Chronic intervillositis do not have a current standardized determination and there are few studies on this entity. Most important point is high rates of recurrence. Differential diagnosis and misdi- agnose is an important pathologic challenge. CHI diagnosis is made microscopically by histology of the placental tissues. The diagnosis can also be made by examing histology of chorionic villous sampling in the first trimester. E-PS-19-029 Gaucher Disease involment of mediastinal lymph node case report M.L. Yamac*, E. Kilic Bagir, T. Toyran, A. Das Cerci, M. Ergin, D. Gümürdülü *Cukurova University, Turkey Background & objectives: Gaucher disease is a lysosomal storage disease characterized by a genetic autosomal recessive transmission because of the gene encoding glucocerebrosidase enzyme defect. And affects multi-organs such as RES, pulmonary. Lymph node infiltration is common manifestation but has limited reports. Methods: here in we report a 11-year-old female presented at the age of 13 months with anaemia, thrombocytopenia and hepatosplenomeg- aly clinical symptoms, bone marrow biopsy, enzyme assay and gene mutations confirmed Gaucher disease type 3. Patient had been receiv- ing enzyme replacement therapy for 9 years. Cervical and mediastinal multiple lymphadenopathies detected from abdominal/ thoracal CT and MRI. Results: Biopsy had done from mediastinal lymph node with suspi- cion of lymphoma or tuberculosis. Mediastinal lymph node biopsy showed that lymph node structure completely effaced by a diffuse Gaucher cells infiltration of lymphoid tissue at the big area. Gaucher histiocytes had with finely fibrillar, wrinkled paper-like cytoplasm and eccentric nuclei. They were positively stained with PAS and iron by histochemical method. No microorganisms or malignant changes were detected. Conclusion: In Gaucher Disease there are limited case reports about mediastinal and mesenteric lymph nodes. In this case enzyme replace- ment therapy had shown limited efficacy for the presentation and treatment of lymph node involvement. The relation between enzyme replacement therapy and lymphadenopathy development is unclear. We presented a rare finding in Gaucher Disease and we think that more studies should be done for treatment and clinical manifestations in such cases with systemic lymph and organ involvement. Funding: Cukurova University E-PS-20 | E-Posters Pathology in Favour of Developing Countries E-PS-20-002 Is the histological type of tumour or molecular profiling of a tumour more relevant for the choice of therapy; a case report of AFP-producing carcinoma with an unknown primary location N. Bilalovic*, F. Erkan Akay, G. Berić Jozić *Department of Clinical Pathology & Cytology, Clinical Center, Uni- versity of Sarajevo, Bosnia and Herzegovina Background & objectives: Background & Objective: We present clinicopathological features and survival outcomes of primary alpha- fetoprotein (AFP)-producing carcinoma with an unknown primary location that responded significantly to immune checkpoint inhibitor (ICHI) atezolizumab. Methods: Case: A 42-year-old female patient was admitted to the hos- pital with symptoms of headache, transient dysphagia, constipation, and bloating. Her FDG-PET scan revealed hypermetabolic masses in the left temporal lobe (29x24mm), in the left upper lobe of the lung, and two nodules in the left adrenal gland. Results: The patient underwent surgery after being diagnosed with adenocarcinoma, due to morphological findings, at a minor pathol- ogy department. As the specimens arrived at our centre, the diagno- sis was revised to AFP-producing tumours with an unclear primary tumour site. Her immunohistochemical markers displayed positivity for Arginase 1, HepPar 1, Glypican 3 and AFP, which is characteris- tic of hepatocellular carcinoma. Hence, she received chemotherapy as first-line treatment, but the tumour was resistant. Her AFP levels, which was 220 ng/mL at the beginning of therapy, surged to 13917 ng/mL (the normal range is 0–40 ng/mL), and she developed new metastases. Conclusion: Given the limited number of AFP-producing tumours, it is challenging to identify precise therapy choices through extensive clini- cal trials. Moreover, recent research has revealed that PD-L1 negative tumours with high TMB (defined as 16–20 Muts/Mb) respond favour- ably to ICHI. On that account, this paper’s objective is to portray how PD-L1, PD-1, and TMB might be possible biomarkers for malignancies with high AFP levels, perhaps elucidating viable treatment strategies.