ECP 2022 Abstract Book

Virchows Archiv (2022) 481 (Suppl 1):S1–S364 13 Results: The specimen was 1737g and the ovary was replaced by a 21x17x10cm partly solid tumour, with capsular rupture. The specimen was extensively sampled with 2 fragments / cm. On histological examination the tumour was composed by tissue of all germinal layers, with areas of skin and cutaneous appendages, adipose tissue, cartilage, respiratory and gastrointestinal epithelium. No immature neuroepithelium or neurorosettes were identified. The fallopian tube and peritoneal nodules showed multiple foci of mature glial tissue, establishing the diagnosis of solid mature ovarian teratoma with GP. Peritoneal fluid was negative for neoplastic cells. Conclusion: This case highlights the importance of a complete dif- ferential diagnosis in a patient presenting with disseminated perito- neal disease and increased serum levels of neoplastic biomarkers. Benign entities should be considered, such as GP in the context of an ovarian teratoma. Two main explanations are proposed for the origin of GP, being glial metaplasia and cellular spread from the teratoma itself. This case supports capsular rupture as the main event for GP, however further investigation is needed to clarify both mechanisms. E-PS-09-027 The role of mast cells in the morphogenesis of cervical cancer A. Filin*, I. Sertakov, M. Popov, E. Verbitskaya, V. Shishkina *Voronezh State Medical University, Russia Background & objectives: Cervical cancer has been and remains one of the main trends in oncology, especially among people of non- reproductive age. The role of mast cells in tumour oncogenesis is still unclear, including in cervical cancer. Methods: The biopsy material obtained from 21 women between the ages of 25 to 74 years, exclusively with cervical cancer, without other pathologies of the reproductive organs. The mast cells stained with tryptase and chymase antibodies. Mast cells were analysed in the tumour and along the periphery of the tumour process. The degree of mast cell degranulation has been established. Results: During the research we were trying to work out the corre- lation between mast cells and some important morphological indi- cators. We have studied the distribution of mast cells and the depth of tumour invasion, the mitotic activity of the tumour, severity of peritumoral inflammation. No correlations were found. It turned out that with an increase in the degree of differentiation (from high to low-differentiated), there was a tendency to decrease the number of mast cells. But this result was not statistically reliable either. However, the largest number of degranulated cells is located in the tumour itself, and not on its edge. Conclusion: The relationship between the distribution of mast cells and the depth of invasion, mitotic activity and severity of inflammation was not revealed. Degranulation of MC occurs actively in the tumour, and not in the invasive edge. It is possible to continue the study of the role of mast cells in the morphogenesis of cervical cancer, but only taking into account the functional activity of mast cells. E-PS-09-028 Vaginal sarcoma with COL1A1- PDGFB fusion: a rare and newly described fibrosarcoma like neoplasm C.M. Vieru*, F. Alijo Serrano, B. López Martínez-Bernal, M. Cebollero Presmanes, A.J. Van Der Biezen, M.N. Villca Huayta, M.L. Abascal, P. Nuñez Ramos, C. Agra Pujol *Hospital General Universitario Gregorio Marañón, Spain Background & objectives: Recent advances in molecular biol- ogy have allowed to define a new uterine sarcoma, with COL1A1- PDGFB fusion and only 4 cases described in the literature. We describe the fifth case in order to provide more knowledge about this entity. Methods: We are reporting the only case of uterine fibrosarcoma like neoplasm with COL1A1-PDGFB fusion diagnosed in our hos- pital and describe clinical, radiological, histopathological, immu- nophenotypic and molecular features. This is a 44-year-old female with no medical history of interest except for a dermoid cyst of left ovary operated 15 years ago. Results: The exophytic tumour of the cervix observed in imag- ing tests was biopsied and showed a malignant neoplastic prolif- eration, treated with anterior pelvic exenteration and intraopera- tive radiotherapy. Macroscopically, it was a big (6,5x5,5x3 cm) lobulated whitish lesion with fibrous consistency. Histologic examination revealed a spindle cell neoplasm with mild nuclear atypia, low proliferative activity and no necrosis. Immunohis- tochemical stains were positive for CD34, CD10 and p16 and negative for epithelial, muscular and melanic markers, ER, PR, cyclinD1, DOG1, EMA, BCOR, SS18-SSX, STAT-6 and pan- TRK. Gene fusion study (Archer FusionPlex Sarcoma Panel) identified COL1A1-PDGFB fusion, the final diagnosis being sarcoma with COL1A1-PDGFB rearrangement, AJCC Stage pT2pNxpMx. Conclusion: There is a wide variety of uterine mesenchymal tumours whose understanding improved thanks to recent advances in molecular biology, that allowed to define a new group of uter- ine fibrosarcoma like neoplasms. It includes a new entity with COL1A1- PDGFB fusion, with only 4 cases reported in the lit- erature and not yet described in the WHO classification of female genital tumours. At the time of this work, our patient is doing well, waiting for a radiological examination and neovaginal dehiscence surgery. E-PS-09-029 Indoleamine 2,3-dioxygenase expression in ovarian carcinoma W. Babay, N. Boujelbene, S. Baroudi, S. Dhouioui*, H. Ouzari, K. Mrad, I. Zemni, I. Zidi *Laboratory Microorganismes and Active Biomolecules, Sciences Faculty of Tunis, Tunisia Background & objectives: Indoleamine 2,3-dioxygenase (IDO) is an enzyme acting as immune modulator through suppression of T-cell immunity. IDO is overexpressed in various cancers. This study aims to investigate the distribution of IDO expression in ovarian carcinoma and its correlation with clinic-pathological characteristics. Methods: Twenty-one cases of ovarian tumours were enrolled for IDO immunohistochemistry. We studied both tumour tissues and adjacent normal tissues. Correlations between IDO expression and clinico-pathological parameters were also examined. Results: The mean age of patients was 54 years. IDO was expressed in all tumour tissues and not in normal tissues (Mann- Whitney test: p<0.0001). High IDO expression (Mean of positive cells=71%) concerned tumour size >50mm (Mean=116mm). Low IDO expression (Mean of positive cells=25%) concerned tumour size not exceeding 50mm (Mean=70mm). No difference in IDO expression was linked to disease characteristics, nor to metastasis (p>0.05). Conclusion: Altogether, our preliminary results showed that IDO could be proposed as a candidate biomarker useful for the advance- ment of ovarian carcinoma profiling. S263