ECP 2022 Abstract Book

Virchows Archiv (2022) 481 (Suppl 1):S1–S364 13 E-PS-09-055 Langerhans cell histiocytosis: a case report and review of the literature D. Nunes*, A.R. Jucá Parente, B. Sobreira Camilo Soares, J. Carneiro Melo, J. Lima Galvão, A.C. Cardoso Fernandes, I.M. Araújo e Silva, J. Nascimento *University of Fortaleza, Brazil Background & objectives: Langerhans cell histiocytosis is a rare group of diseases that comprises a wide spectrum of diseases initially known as histiocytosis and there are few cases described in the litera- ture on topography of the vulva. Methods: Report case of 65 years old woman in the climacteric period, with a clinical history of long lasting vulvar burning and itching, combined with the presence of erytema and cracks, with a diagnostic suspicion of sclerosus lichen was submitted to a vulvar biopsy. Results: The histopathologic showed an atypical cell proliferation at the submucosa, abnormal immature Langerhans cell prolifera- tion rounded by eosinophils, macrophages and Birbeck granules. Immunohistochemical reveals positivity to CD1, CD68, Ki-67 and S-100 protein markers and negativity to AE1/AE3, CD138, CD20, CD3, CD30, Ki-1, CD45, HMB45, Melan-A, MPO, MUM 1 and SOX-10 markers. Conclusion: LCH should be considered in the diagnosis of vulvar lesions and when it occurs in only at this site it has the potential for aggressive clinical behaviour, either as a local recurrence or as a disseminated disease. E-PS-09-056 Small cell carcinoma of ovary, hypercalcemic type: the syner- gism of immunostains and molecular studies S. Aviel-Ronen*, I. Schwartz, S. Caspi *Sheba Medical Center / Ariel University, Israel Background & objectives: Small cell carcinoma of ovary, hypercal- cemic type (SCCOHT) is a rare tumour with typical immunoprofile and mutations in SMARCA4. Here we describe a SCCOHT case with unusual immunostain results. The combination of molecular studies and immunostains enabled the diagnosis. Methods: The medical records, imaging tests, pathological find- ings and molecular studies of the patient have been studied and are presented. Results: A 12 years old female premenarche adolescent presented with abdominal pain. Pelvic US revealed enlarged ovary of 9 cm in diameter and oophorectomy was performed. Histological evaluation showed undifferentiated small round cell malignant tumour with positive staining for SALL4 (focally), MNF116 (focally), synapto- physin, CD99 (diffusely), Fli-1 (diffusely), BRG1 (focally), SATB2, TLE1 and BCL1 with Ki67 of 80%. The stains for CD30, LCA, inhibin, SOX10, PLAP, OCT4, D2-40, CD117, AFP, myogenin, CD3, CD20, AE1/AE3, EMA, CK7, CK20, FOXL2, calretinin, myogenin, desmin, chromogranin, CD56, WT1 and NKX2.2 were all negative. Various FISH studies were negative for rearrangements but FoundationOne Heme test identified a mutation in SMARCA4 (splice site 2438+1G>A). Conclusion: A diagnosis of SCCOHT was made in spite of neg- ative staining for WT1 and retained but attenuated staining for BRG1. It is the combination of elaborated immunostaining, FISH studies and extensive genetic analysis that brought to this rare diag- nosis. As genetic studies become more prevalent, it is expected to note growing variability in gene expression for any described gene alteration, that should not exclude the related diagnosis. The synergism of the various available techniques is crucial for accurate diagnosis. E-PS-09-057 Transitional cell neoplasm in both ovaries with serous tubal intraepithelial carcinoma-like lesion, ovarian origin or metastases? C. Ariño-Palao*, R. Meléndez Gispert, I. Carretero-Barrio, P. García Abellás, I. González García, E. Moreno Moreno, B. Pérez- Mies, J. Palacios *Ramón y Cajal University Hospital, Spain Background & objectives: The ovary is the most common location of metastases in the gynaecological tract. Serous tubal intraepithelial carcinoma (STIC) is considered a high grade serous carcinoma precursor but metastases to the epithelium of the fallopian tube can mimic STIC. Methods: We present a 64-year-old woman with history of neph- roureterectomy and recurrent high-grade urothelial carcinoma of the bladder. A CT scan revealed a left ovarian mass suspicious of malignant primary ovarian neoplasm, so she underwent surgical staging including hysterectomy with bilateral salpingooophorec- tomy and omentectomy. Results: The left ovary (17cm) and right ovary (4cm) showed a neo- plasm with a solid-transitional cell pattern. The left fallopian tube showed in situ epithelial proliferation with nuclear stratification, marked nuclear pleomorphism, mitotic figures and positive p53 stain- ing resembling a STIC. Although the morphological appearance in the ovaries and fallopian tube was concordant with a high grade serous carcinoma, the differential diagnosis included metastatic urothelial carcinoma due to its previous history. Immunohistochemistry showed strong and diffuse nuclear staining for p53 but negativity for WT1. In addition, the tumour showed diffuse cytoplasmic positivity for CK7 and CK20, p63 and GATA3, concordant with a metastatic urothelial carcinoma. Conclusion: Urothelial carcinoma metastases to the ovary and fal- lopian tube are extremely rare, with only few cases described in the literature. Diagnosis is not easy due to its resemblance to primary ovarian carcinomas with a transitional cell pattern. In present case, the presence of STIC-like lesions added difficulty to the recogni- tion of the metastatic nature of the lesions. Therefore, the final diagnosis should be made based on the clinical history and the immunohistochemical profile. E-PS-10 | E-Posters Haematopathology E-PS-10-001 Follicular lymphoma masquerading as Crohn’s disease. A case report with literature review F.F. Cheo* *Singapore General Hospital, Singapore Background & objectives: While Follicular lymphoma (FL) is largely a nodal disease, it can be primarily extranodal, and mimic other neo- plastic or non-neoplastic conditions clinically and radiologically. We report a patient with FL presented with a terminal ileal ulcer clinically mimicking a Crohn’s disease. Methods: A 56 year-old man with no past medical history had positive faecal occult blood test upon screening in year 2017. A circumscribed terminal ileal ulcer was identified on colonos- copy. Biopsy revealed an ulcer base and inflamed granulation tissue with no granuloma, infective organism or dysplasia. S271