ECP 2022 Abstract Book

Virchows Archiv (2022) 481 (Suppl 1):S1–S364 13 and weight loss. During the exploration, entero-CT scan has revealed extensive thickening of the entire right colon, as well as luminal collapse and presence of lymphadenopathy at the ileocecal junction. Histological examination revealed a disorganized architecture of the colonic and ileocecal mucosa with elongated, sinuous and distorted crypts. In addition, we noted the presence of multinucleated cells presenting a muriform aspect, with faded nuclei, voluminous and nucleolated in places. The chorion was inhabited by a rich inflammatory lymphocyte infiltrate mixed with neutrophils. neutrophils were in exocytosis producing crypt abscesses. Conclusion: Herpes simplex virus (HSV) is a known cause of gastrointestinal infections, especially in immunocompromised patients. A few rare cases of colonic herpetic lesions in patients with IBD have been reported. With immunocompromised individu- als, HSV regains higher pathogenicity and higher ease of dissemi- nation. Therefore, it would be wise to search for HSV in immuno- compromised patients with IBD. The gold standard of diagnostic tests is the search for HSV by PCR and immunohistochemistry on biopsies. E-PS-07 | E-Posters Digestive Diseases Pathology – Liver / Pancreas E-PS-07-001 EBV associated Lymphoepitelioma-like cholangiocarcinoma: case report and literature review M. Garcia Martos*, I. Peligros *Hospital General Universitario Gregorio Marañón, Spain Background & objectives: Lymphoepitelioma-like cholangiocarci- noma (LELCC) is an unusual type of cholangiocarcinoma first report in 1996 by Hsu et al. LELCC EBV+ is a neoplasm with better prognosis than conventional cholangiocarcinoma (CC), and female and young predominance. Methods: We present a 49 years old male with history of primary sclerosing cholangitis, obesity, IBD and ischemic cardiopathy. An abdominal CT scan revealed two nodules in right hepatic lobe (18 & 24 mm) and pathologic regional lymph nodes. Liver needle biopsy was performed. Liver biopsy was diagnosis of poorly dif- ferentiated carcinoma, so surgery was indicated. Results: Patient underwent surgery with right liver excision, cholecystectomy and regional lymph nodes dissection. Histo- logically tumour was composed by poorly differentiated cells arranged in nest, cords or lobules with focal glandular differen- tiation. Between neoplastic cells, there was a dense lymphoid infiltrate with lymphoid follicles. That reactive lymphoid infil- trate obscured the malignant epithelial cells. Lymph nodes were positive. Malignant cells were IHC positive for CK7 & CK19, and negative for Hepar1. EBV was demonstrated by ISH. No loss of MMR was demonstrated, EGFR and KRAS were WT, and PDL1 expression (SP142) was high. 3 months after surgery the patient is alive although he is on QT because of remain loco regional disease. Conclusion: LELCC is a rare variant of CC with strong asso- ciation with EBV and distinctive clinical behaviour and patho- logical features (no more 65 cases published). There is marked female predominance, although our case is a male and young age. The clinical outcome for EBV associated LELCC is better than CC, may be due to the dense lymphoid infiltration, which is a host defence against the tumour. LELCC has higher expres- sion of PDL1 and this could have implications for potential treatment strategies. E-PS-07-002 Unusual association of primary high grade neuroendocrine tumour and large cell neuroendocrine carcinoma of the liver – a case report B. Akiki*, N. D’Haene, C. Maris, M. Remmelink, P. Demetter *Erasme University Hospital, Belgium Background & objectives: Neuroendocrine neoplasms in the liver are usually metastatic and primary hepatic neuroendocrine neoplasms are rare, representing about 0.3% of all neuroendocrine neoplasms, with, to our knowledge, 153 cases reported in the English literature. Methods: This case concerns a 44-year-old man, previously healthy, who presented to the emergency department for abdominal pain, vomiting, and watery diarrhea. An abdominal CT-scan was performed and revealed a 12 cm large, heterogeneous hepatic mass, located in segment IVb. Pre- operative fine needle biopsy of the mass suggested a well-differentiated (grade 2) neuroendocrine tumour. Results: Grossly, the left enlarged hepatectomy specimen was almost totally replaced by a heterogeneous solid mass. Histo- logically, the tumour presented two components: a well differ- entiated one with organoid architecture and cells presenting a “salt and pepper” appearance, associated with a poorly differ- entiated component made up of large cells. Necrosis was evalu- ated to 50%. Both components demonstrated immunoreactivity for synaptophysin, chromogranin and INSM-1. Mitotic count was higher than 20 mitosis/2mm2, with a proliferative index, evaluated by Ki67, of 23%. Cells in the poorly differentiated area over-expressed p53, which was confirmed by molecular study. Primary hepatic tumour, associating a grade 3 neuroen- docrine tumour and a large cell neuroendocrine carcinoma diag- nosis was made. Conclusion: The concurrent occurrence in the liver of a high grade neuroendocrine tumour and a neuroendocrine carcinoma has, to our knowledge, never been reported in the English litera- ture. Primary hepatic neuroendocrine neoplasms are slow grow- ing tumours that usually present at advance stage; their diagnosis remains challenging and should be made after elimination of other possible primitives. The results from our molecular analy- sis suggest that the neuroendocrine carcinoma component devel- oped from the neuroendocrine tumour component after TP53 mutation. E-PS-07-003 Medullary carcinoma of the pancreas: a case report and review of the literature M. Hanks*, G. Irving, A.M. Zaitoun *Nottingham University Hospitals NHS Trust, United Kingdom Background & objectives: Medullary carcinoma of the pancreas is a rare tumour with a five-year survival rate of approximately 13%. Previously, this entity was regarded as a subset of poorly differentiated ductal adenocarcinomas, however, they have a distinctive morphologi- cal and molecular characteristic. Methods: The aetiology and pathogenesis are not clearly under- stood however several studies have shown strong associations with a first degree relative with previous cancer and hereditary nonpoly- posis colorectal cancer. Medullary carcinoma does not respond well to chemotherapy making surgery the first line treatment. It is important to differentiate from poorly differentiated adenocarci- noma with Epstein-Barr Virus infection as this mimics medullary carcinoma. S239