ECP 2022 Abstract Book

Virchows Archiv (2022) 481 (Suppl 1):S1–S364 13 Conclusion: In summary, the use of ancillary testing, including immunohistochemistry, is helpful in the identification, differential diagnosis, and classification of high grade endometrial cancers. E-PS-09-052 Microenvironment of endometrial cancer: are there new prog- nostic and theranostic biomarkers? G. Sahraoui*, M. Manai, A. Maaoui, H. Douik, I. Nasri, N. Ben Hamida, L. Charfi, K. Mrad, R. Doghri *Pathology Department, Salah Azaiez Institute, Research Labora- tory LR21SP01, Tunis, Tunisia Background & objectives: Endometrial carcinoma is an ever-growing gynaecologic malignancy worldwide. PD1/PDL1 immune checkpoints are among the important players of immunosuppression in the tumour microenvironment. We determined the level of PD1 and PDL1 expression in the tumour environment and their impact on prognosis. Methods: This was a retrospective, descriptive study of a series of 46 cases of endometrioid carcinoma at the Salah Azaiez Institute collected between 2007 and 2017. Results: Our series included 70% of postmenopausal patients. Stage I (45.6%) and grade 1 (41.3%) were the most dominant. Immunohistochemical analysis showed a higher expression of PDL1in tumour-infiltrating lymphocytes (26%) than in tumour cells (17%). As for PD1, this protein was expressed in 63% of cases. Statistical correlation revealed a correlation between PDL1 expression and menopausal status (P=0.001 and P=0.014). Indeed, PDL1 expression in epithelial cells was positively associated with less than 50% myometrial invasion (P=0.037). However, no asso- ciation was found between PD1 expression and histoponostic fea- tures. We found that endometrial carcinoma has a heterogeneous immunogenic profile, which emphasizes the controversial role of PD1/PDL1 immune checkpoints in tumour progression. Conclusion: PD1/PDL1 expression in endometrioid adenocarci- noma is remarkable, without relevant association with prognostic elements. Future research on large cohorts may be useful to detect clearly the role of biomarkers in tumour progression. E-PS-09-053 Pregnancy luteoma: a rare lesion as an incidental finding. Case report G.G. Yange Zambrano*, G. Moreno-De-Juan, M.d.M. Del- Barrio-Molina, Y. Carreres-Ortega, J.C. Yange-Zambrano, H.G. Sarmiento-Moncayo, I. Gallego-Gutierrez *Hospital Mateu Orfila, Spain Background & objectives: Pregnancy luteomas (PL) are rare, non- neoplastic proliferation of luteinized cells during pregnancy, forming single or multiple nodules in ovaries. Are thought to be caused by the hormonal effects of pregnancy. Most are asymptomatic and incidentally discovered during imaging or surgery. Methods: 33-year-old woman in her second full term pregnancy, with gestational-diabetes, was admitted in obstetrics ward for occlusive placenta previa. The patient underwent caesarean sec- tion. A female baby was born without complications. Intraopera- tively, surgeons found right sided ovarian mass measuring 3,7cm, semi-soft, brownish. Suspecting that it was an ovarian neoplasm, unilateral oophorectomy was performed. The specimen was sub- jected to histopathological examination. Results: Macroscopic-examination showed an enlarged ovary measuring 3.7x2.5x2cm. Cut surface of the ovary was circum- scribed, soft, fleshy, and gray-brown. Microscopically, the lesion showed well defined margin, with solid growth pattern of polygo- nal luteinized cells with abundant amount of finely granular eosin- ophilic cytoplasm, and frequently showed follicle-like spaces filled with eosinophilic-fluid. Nuclei were small, round, vesicular with prominent nucleoli, that did not contain stainable lipid. Occasional mitotic figures, without areas of necrosis. Reinke crystals were not found. Immunohistochemical-stains showed strong-positivity Calretinin, Inhibin-A, Melan-A; were negative for CKAE1/AE3, CKCam5.2, S100; and Reticulin enveloped clusters of cells. The final diagnosis of PL was made. Two years later the patient is asymptomatic and without recurrence. Conclusion: PL is a rare tumour-like lesion mostly appearing in late-pregnancy, probably secondary to high-levels of human- chorionic-gonadotropin, that will usually regress spontaneously. We present a case of PL detected incidentally during a caesarean- section. It is important to bear this condition in mind, as it is rare and thus misdiagnosis and inappropriate treatment may occur. The main-differential-diagnoses include Steroid-cell- tumour, Luteinized adult granulosa cell tumour or thecoma, Juvenile granulosa cell tumour, Metastatic-carcinoma. The gross, immunohistochemical-staining, and reticular-fiber-staining results may help diagnose this disease. E-PS-09-054 Chemotherapy and breast cancer gene (BRCA) mutation associate with quantified tumour infiltrating lymphocytes in high-grades serous ovarian carcinoma J. Machuca-Aguado, E. Rodríguez-Zarco, A.F. Conde, A. Gutier- rez-Domingo, J.J. Rios-Martin, M. Idoate* *University Hospital Virgen Macarena, Spain Background & objectives: There is a controversy about the role of tumour infiltrating lymphocytes (TILs) and BRCA gene mutation as prognostic biomarkers in high-grade serous ovarian carcinoma (HGSOC). By this reason, we have evaluated the clinical significance of quantified TILs in HGSOC. Methods: A series of 48 HGSOC III or IV staged (FIGO) cases were studied. H&E representative sections were evaluated in a blinded manner semiquantitatively and digitally using learning image analysis algorithms. Intraepithelial and stromal TILS in representative areas were selected. BRCA gene mutation was determined by next generation sequencing using Illumina platform. Statistical evaluation using SPSS software was applied. Results: Morphologically, in tumours with neoadjuvant treatment a striking intraepithelial TILs infiltration was observed. BRCA gene mutated and neoadjuvant treated carcinomas cases were 35% and 50%, respectively. Stromal TILs in both neoadjuvant treated and BRCA gene mutated tumours were higher than non- neoadjuvant and BRCA gene mutated ones (p=0.038). Neoadjuvant chemotherapy treated carcinomas showed a higher number of stromal TILs than in non-neoadjuvant ones, although differences were not statistically significant. No difference of TILs density in mutated in respect with wild-type BRCA gene carcinomas was observed. The median of patient survival was 70 months, with no difference between mutated and wild-type BRCA gene mutated neoplasms. Conclusion: Neodjuvant chemotherapy plus BRCA gene mutation produce a significant increase in stromal TILs density in HGSOC, but it has not relationship with survival. BRCA gene mutation has not been associated with a higher survival. We postulate a possible TILs recruiting effect of neoadjuvant chemotherapy on BRCA gene mutated tumours. S270