ECP 2023 Abstracts

S264 Virchows Archiv (2023) 483 (Suppl 1):S1–S391 13 for eventual immunohistochemical and/or molecular analyses. The technique can be useful for clinical and research purposes. However, a period of adaptation to the method is required to allow technicians and pathologists to become familiar with the method to reach an adequate diagnostic accuracy. After this training period, the agreement between FuCM and conventional microscopy diagnoses may be as high as 83%. E-PS-10-045 Uterine cervix blue nevus: a 10 years study from a spanish hospital S.J. Marín Asensio*, O. García-Galvis, M.G. Rodríguez Guevara, J. Alzoghby-Abi-Chaker, C.J. Martinez Martinez, S. Sáez-Álvarez *Complejo Asistencial Universitario de León, Spain Background & objectives: The gynaecological mucosal blue nevus is a rare lesion, usually referred as analogous of the cutaneous blue nevus. Usually is an incidental diagnosis and has been described as a benign macular or papular lesion with a characteristic dark-blue pigmentation. Methods: We reviewed our institution diagnosis on cervical specimens since 2013, including conization and hysterectomies, showing 5 cases of CBN. The average age of the patients was 54, the most frequent surgical intervention was hysterectomy (4/5) and in every one of our cases the diagnosis was an incidental finding. Results: Microscopically we could see dendritic or spindle cells with elongated nuclei and cytoplasms with intense melanin pigmentation, immersed in a stroma with variable desmoplasia. The lesions were mainly in the superficial endocervical channel, subendothelial. No mitosis or atypia were observed. Conclusion: CBN is a rare entity that offers no special diagnosis dif- ficulty, but we should be aware of it in case of a pigmented lesion that appears on cervical channel or exocervix. The diagnosis is usually done on HE stains alone but ancillary techniques such as Perls or S100 or others melanocytic markers would be helpful in some cases. E-PS-10-046 A case of unilateral ovarian splenosis seen after domestic abuse L.D. Micoogullari*, A. Orgen Calli *Izmir Katip Celebi University, Ataturk Training and Research Hospi- tal, Department of Pathology, Turkey Background & objectives: Ectopic splenic tissue seen throughout the body may represent a case of accessory spleen, splenosis or sple- nogonadal fusion. In this case, a solitary ovarian mass in a 42-year-old female diagnosed as ovarian splenosis is presented. Methods: Intraoperative consultation was requested for a bilateral salpingo-oopherectomy specimen. Gross examination revealed a left adnexial specimen consisted of a hydropic tuba and an ovary of 8x4x3 cm in size. Cut-surface of the ovary showed a well-demarcated, solid mass with hemorrhagia. Paraffin-embedded tissue sections of this specimen were evaluated for the histopathological characteristics. Demographic, clinical, and imaging data were collected. Results: A 42-year-old female admitted to emergency service with pain at the bilateral iliac regions. She underwent left hemicolectomy and splenectomy due to domestic abuse -stabbing incidence- 4 years ago. To rule-out any abdominal emergencies computed tomography (CT) was obtained. CT revealed a solitary mass with both cystic and solid components at the left ovary. Intraoperative consultation was requested for the left ovarian mass since it’s nature could not be cleared out. Histopathological examination showed typical red and white pulp with lymphatic follicles and penicillary arterioles consistent with splenic tissue. Due to the history of splenectomy and the location of lesion diagnosis of “unilateral ovarian splenosis” was rendered. Conclusion: Ovarian splenosis usually presents as a component of extensive pelvic splenosis. Thus, a solitary ovarian splenosis may mimic an abdominal or ovarian tumour. In our case, the localization and the previous history of being stabbed and undergoing splenectomy could explain auto-transplantation of splenic cells. To conclude, soli- tary ovarian splenosis is a rare lesion which can cause diagnostic prob- lems. In the literature, apart from our case, there are only 8 cases of ovarian splenosis reported. E-PS-10-047 Immunohistochemical evaluation of microsatellite instability in random selected endometrial biopsies K. Mikus Kuracinova*, V. Mihál, V. Poorova, P. Janega, M. Sekerešová *Institute of Pathological Anatomy, Medical faculty, Comenius Uni- versity, Slovakia Background & objectives: In our retrospective study, we immunohis- tochemically analysed the expression of MMR proteins in randomly selected endometrial biopsies. Immunohistochemistry is a useful and simple form of testing for Lynch syndrome, a widely available method, unlike genetic testing for germline mutations. Methods: We evaluated biopsy material taken from curettage or uterine resections with the histological results of endometrioid intraepithelial neoplasia or endometrial cancer followed by immunohistochemical stain- ing for MMR gene protein expression. Immunohistochemically positive staining is defined as the clear nuclear expression and loss of protein expression is the complete absence of nuclear staining in tumour cells. Results: In our series, we evaluate biopsy material from 46 patients consisting of curettage (16 samples) or uterine resections (30 samples). Based on the diagnostic criteria and immunohistochemical evaluation, our analysis showed a loss of one or more MMR proteins was present in 24% of cases, so in 10 patients. Loss of MLH1 expression was pre- dominant (in 17 % of cases), and MSH2 and PMS2 expression was absent in 13 % of all cases. According to our findings, the prevalence of Lynch syndrome is relatively high, although we acknowledge that it would need a larger statistical sample. Conclusion: Immunohistochemistry can be performed to detect MMR proteins with the same accuracy on curettage or hysterectomy biopsy samples in use to screen Lynch syndrome and is increasingly used to screen patients with suspected Lynch syndrome. We assume, that routine immunohistochemical testing of each uterine biopsy for MMR proteins may be the gold standard, as in colorectal cancer, and it can lead to earlier detection of patients with Lynch syndrome and identifi- cation of genetic mutations. Funding: (BIOMEDIRES – II. phase, ITMS: 313011W428) E-PS-10-048 Non-syndromic sex cord tumour with annular tubules: two cases of a rare entity C. Mora*, F. Cunha *Serviço de Anatomia Patológica, Instituto Português de Oncologia de Lisboa Francisco Gentil, Lisbon, Portugal Background & objectives: Sex Cord Tumour with Annular Tubules (SCTAT) is a rare type of ovarian tumour. Although associated with Peutz-Jegher Syndrome in a third of cases, non-syndromic cases should be suspected when unilateral, and usually has an excellent prognosis after surgical resection. Methods: Herein, we report the clinicopathological features of two cases of sex cord tumours with annular tubules, non-related to Peutz- Jeghers syndrome, along with a brief review of the literature. Case 1 refers to a 31-year old woman with a right adnexal mass, and case 2 to a 34-year old with a left ovary mass, both presenting with abdominal pain. Results: An anexectomy was performed after scans demonstrated unilat- eral ovary-confined disease, along with lymphadenectomy in the second case. Grossly, tumours were 15cm and 28cm, with yellow solid and cystic areas, intact capsule, and fallopian tube was unaltered. Microscopically, they were composed of rounded nests with complex tubules, encircling a hyaline material, without calcifications. The cells had round nuclei with