ECP 2022 Abstract Book

Virchows Archiv (2022) 481 (Suppl 1):S1–S364 13 Mixed acinar neuroendocrine tumour: a rare case of pancreatic tumour E. Souka*, G. Stanc, G. Galanopoulos, L. Karelis, O. Tzaida, E. Kontis *Pathology Department Metaxa Cancer Hospital, Greece Background & objectives: Acinar cell carcinomas are rare tumours, representing 1-2% of all pancreatic adult tumours. We present a case of acinar pancreatic carcinoma and short review of the literature Methods: A 81-year -old male patient presented with abdominal pain and weight loss. CT-imaging revealed a well demarcated tumour measuring 4.5 cm in greatest diameter at the pancreatic body. On sectioning the tumour was totally encapsulated, solid, tan with fleshy consistency. Results: On low power microscopic examination, the tumour was cellular and macronodular with fibrous strands. On higher magnification it had an acinar, trabecular, and solid growth pattern. The neoplasm consisted of a mixture of small-sized cells with hyperchromatic nuclei and medium-sized cells with distinct nucleolus and eosinophilic granular cytoplasm PAS(+), PASD(+), AB(-) on histochemical examination. There was increased mitotic activity (15-20mitosis/10HPF) and spotty necrosis. The immunohistochemical analysis revealed a CKAE1/ AE3(+), CK7(+), CK19(+), CK8/18(+), Trypsin diffusely (+), Chromogranin-A diffusely (+), Synaptophysin(+) , NSE(+), CD56(+), Vimentin (-), MUC5AC(-), TTF1(-), PAX8(-), CDX2(- ), Ki-67 25% phenotype. The diagnosis was consistent with acinar carcinoma with extensive neuroendocrine markers expression, corresponding to mixed acinar- neuroendocrine carcinoma subtype. Conclusion: Mixed pancreatic carcinomas include all combina- tions of ductal, acinar, or neuroendocrine differentiation, com- monly a mixture of predominant acinar and neuroendocrine com- ponent. In case of a discrete neuroendocrine component accounting >30% of the tumour, the neoplasm is designated MiNEN. Alter- natively, they can show extensive mixture of acinar and neuroen- docrine cells, whereupon they are designated as acinar carcinoma, mixed subtype. They share the same prognosis as pure pancreatic acinar carcinoma. E-PS-07-011 A singular case of primary hepatic extra gastrointestinal stro- mal tumour (EGIST) A. Abrari*, U. Mukherjee *The Rotherham NHS Foundation Trust, United Kingdom Background & objectives: A primary hepatic GIST is an exception- ally rare, barely reported entity, of which we report a singular case. Methods: A 65-year-old female patient with symptomatology and clinical features of a solitary hepatic mass lesion was worked up, with investigations culminating in an ultrasonography-guided biopsy which was examined histologically and subjected to ancil- lary testing. A structured differential diagnosis was established and each entity/group of lesions was excluded systematically, until a conclusion was attained. Results: This biopsy showed a morphologically non-committal lesion, which on concerted diagnostic effort, utilising a broad- based immunohistochemistry panel, which also included GIST determining markers, CD34, c-Kit and DOG-1: was diagnosed as a hepatic extra gastrointestinal stromal tumour (hepatic EGIST). The possibility of secondary hepatic involvement was incontrovert- ibly discounted clinically. Conclusion: GISTs predilect the stomach and small intestine, but these tumours can occur anywhere in the gastrointestinal tract. Extra gastrointestinal stromal tumours [EGISTs] have been reported in the omentum and a slew of cases elsewhere. Our case underpins the importance of a non-dogmatic, broad-based analytic approach in dealing with a morphologically obscure hepatic neo- plasm, which may well turn out to be the rare primary hepatic GIST / EGIST. The management implications of a precise diagnosis, in this situation, cannot be overemphasised. E-PS-07-012 Low-phospholipid associated cholelithiasis syndrome - a case report and literature review J. dos Santos*, G. Miranda, T. Amaro *Unidade Local de Saúde de Matosinhos, Portugal Background & objectives: Low-Phospholipid Associated Cholelithiasis (LPAC) syndrome is a genetic disease associated with a mutation of the ABCB4 gene which codes for protein MDR3, a biliary carrier. It is characterized by the development of biliary lithiasis with no excess of cholesterol secretion. Methods: We report a case of a 54-year-old female with clinical criteria for LPAC syndrome and ABCB4 gene mutation. She had a complex history of cholangitis/pancreatitis recurrence despite cholecystectomy and treatment with ursodeoxycholic acid. Hepatectomy was performed based on imagiologic findings consistent with cholangiocarcinoma. Results: The gross examination revealed three specimens of hepatic tissue, weighing 97,5 gr, the largest measuring 87x40x60 mm. On the cut surface, there were some ill-defined, withish and firm areas; the remainder of the parenchyma was homogeneous and tanned. Histologically, there was no malignant lesion but some signs pointing to biliary duct obstruction were found: mild por- tal fibrosis, sometimes with “onion bulb” pericanalary pattern, ductular proliferation and mononuclear moderate chronic portitis. Few epitheloid granulomas and multinucleated giant cells with cholesterol crystals were also identified. After surgery, the patient developed an abdominal abscess that was successfully managed with antibiotics and drainage. The patient is alive and well, three months post surgery. Conclusion: LPAC syndrome is defined by two of the following criteria: age < 40 years at onset of biliary symptoms, recurrence of biliary symptoms after cholecystectomy, and intrahepatic hyperechogenic foci detected by ultrasound. This case reports LPAC syndrome in a female with two diagnostic criteria and mutation of the ABCB4 gene. Histologically there are no pathognomonic lesions, but variable findings related to intrahepatic lithiasis may be seen. This report emphasizes the importance of pathological examination and multidisciplinarity in LPAC syndrome. E-PS-07-013 Hepatic epithelioid hemangioendothelioma: a case report G. Miranda*, J. dos Santos, L. Cirnes, J. Correia-Pinto, T. Amaro *Unidade Local de Saúde de Matosinhos - HPH, Portugal Background & objectives: Report of the clinicopathological fea- tures of a hepatic epithelioid hemangioendothelioma This entity is an extremely rare, often multifocal, malignant vascular tumour with dif- ficult diagnosis due to the clinical and pathological similarities with other hepatic neoplasms, especially the angiosarcoma. Methods: An 82-year-old man presented with icteric skin and gen- eralized oedema. The abdominal Ultrasound and the Computed Tomography showed a multinodular and heterogeneous liver that was biopsied. S242