ECP 2022 Abstract Book

Virchows Archiv (2022) 481 (Suppl 1):S1–S364 13 investigated with computed tomography (CT) scan of the abdomen, which revealed a large liver mass measuring 16 cm in maximum diameter, occupying most of the right hepatic lobe. The mass had imaging characteristics of cholangiocarcinoma and a CT-guided needle biopsy was performed. Results: Histopathological examination showed fragments of an epithelial neoplasm with adenoid cystic and focally cribriform growth pattern embedded in hyalinized stroma, and necrotic tis- sue. Neoplastic cells were small, with scant cytoplasm and oval to angulated, minimally pleomorphic and hyperchromatic nuclei, with palisading and basaloid areas peripherally, consistent with myoepi- thelial origin. Mitoses were not identified. Almost all neoplastic cells were positive for keratin 7(K7), K19, EMA and CD117 and the myoepithelial component was positive for p63. Morphologi- cal and immunohistochemical findings were consistent with meta- static adenoid cystic carcinoma (ACC). Clinical examination had revealed a 3 cm palpable neck mass, which after fine-needle biopsy was proved to be an ACC of the submandibular gland. Conclusion: ACCs run a slow but progressive course and have a high likeli- hood of distant metastasis. The most common sites of metastases are lung and bone, followed by brain and liver. Liver metastases are often synchro- nous or metachronous with multiorgan metastatic disease and only a handful of studies of isolated liver metastasis have been reported in the literature. Due to the absence of consensus concerning the appropriate treatment, a multidis- ciplinary approach is necessary tomanage this rare and aggressive neoplasm. E-PS-11-028 Spindle cell lipoma in an unusual location, a case report M.M. Buda*, È. Iglesias Martinez, N. Santiago Quispe, A.P. Mar- tinez Aracil, A. Sifre Ruiz, A.I. Ruiz de Angulo Otxaran, M.J. de Diego Rivas *Araba University Hospital, Spain Background & objectives: Lipomas are the most common mesen- chymal tumours, although only 0.6% of them occur in the larynx. We report the case of a 62-year-old man who presented with dysphonia and dyspnea because of a supraglottic mass. Methods: A CT was performed which revealed a fatty density lesion dependent on the left ventricle. The patient underwent lar yngeal microsurger y. Afterwards, light microscopy, immunohistochemistry (IHQ) and molecular pathology studies were made. A literature revision also was performed. Results: A 2.2 x 1.5 cm exophytic lesion was received. Gross pathology of the specimen showed yellow to orange cut sur- face. Microscopic examination revealed a well-circumscribed and non-encapsulated mass underlying normal appearing squamous mucosa. The tumour consisted of mature adipo- cytes, bland spindle cells and occasional pleomorphic multi- nucleated giant cells arranged in a “floret-like” pattern. The stroma alternated myxoid and collagen rich areas. With IHQ studies, stromal cells showed CD34 expression. The adipocyte component was negative for CDK4 and MDM-2. Ki-67 and PHH3 were <1%. Molecular pathology revealed deletion of one copy of the RB1 gene and absence of amplification of the MDM-2 gene. Thus, spindle cell/pleomorphic lipoma (SC/PL) diagnostic was made. Conclusion: Laryngeal spindle cell lipomas are rare, with only six cases reported to date. Due to their benign nature, and in order to avoid overtreatment, it is important to distinguish them from a more aggres- sive entity such as well-differentiated liposarcoma/atypical spindle cell lipomatous tumour (WDLS). SC/PLs and WDLS have multiple histopathological similarities, that’s why the key to distinguish them is based on cytogenetic analysis. WDLS does not show changes in the RB1 gene, while it exhibits MDM-2 gene amplification. E-PS-11-029 Nasal chondromesencymal hamartoma; a rare case report E. Ziadinov, S. Yagci*, E. Yılmaz Akçay, S. Mustafayeva, M. Tepeoğlu, B.H. Özdemir *Başkent University Faculty of Medicine, Department of Pathol- ogy, Ankara, Turkey Background & objectives: The nasal chondromesenchymal hamar- toma (NCMH) is a rare benign tumour of sinonasal tract with predi- lection to paediatric age groups. We present a case of NCMH with characteristic histomorphological features, differential diagnosis and review the literature. Methods: An 8- year-old-girl presented with occasional left sided epistaxis for a year and absence of breathing through the left nos- tril. She had a history of adrenal neuroblastoma with partial adrenal insufficiency and oral corticosteroid therapy. Differential diagno- sis was antrochoanal polyp, angiofibroma inverted papilloma with endoscopic examination. Results: Computed tomography scan revealed a 48x40 mm sized mass; in nasal passage, attached to the septum without bone destruction. Endoscopic excision of the mass showed polypoid white mass with vaguely nodular appearance. Microscopically mass was covered with respiratory epithelium. Stroma was mainly consisted of disorganized benign spindle cells distributed among fine collagen fibres with focal cartilaginous tissue. There were sparse areas with myxoid changes and occasional small vessels, nerve fibres and dilated cystic spaces. No signs of cellular atypia, necrosis and mitoses have been identified. The spindle cells was negative for muscle cell markers (Desmin, SMA and Myogenin). The Ki-67 proliferation index was less than 1%. Final diagnosis was NCMH. Conclusion: NCMH is a rare tumour of upper respiratory tract and may mimic other benign and malignant lesions clinically. The correct diagnosis is essential for proper management. Histopatho- logical features of NCMH are of great assistance for establishing the diagnosis. E-PS-11-030 Bilateral subgemmal neurogenous plaque of the tongue: a case report L. Hasanaliyeva, E. Yılmaz Akçay, S. Yagci*, A. Ok Atılgan, A. Zeynalova *Başkent University Faculty of Medicine, Department of Pathol- ogy, Ankara, Turkey Background & objectives: Subgemmal neurogenous plaque(SNP) is a biphasic neural structure associated with the taste buds and presents as an asymptomatic, normally coloured, papule located in the posterior lateral border of the tongue. We present a rare case of bilateral SNP on tongue. Methods: A 38-year-female patient presented with asymptomatic wounds on bilateral posterior lateral sides of tongue. Hashimoto’s thyroiditis is present in medical profile and she doesn’t smoke. Bilateral biopsy was performed to rule out neoplasia. Results: The surface of both biopsy materials were ulcerated, cut surface were beige coloured, and had soft consistency. Histopathologic examination revealed same features for both biopsies¸ neural plexus composed of irregular, small bundles and scattered separate neural cells underlying the oral squamous epithelium, which showed normal taste buds. Neural cells were spindle-shaped, with oval normochromic nucleus and wavy eosinophilic cytoplasm with no nuclear atypia or mitosis. Deeper parts composed of small nerve fascicles showing scant ganglion cells. There was accompanying reactive lymphoid tissue with S287