ECP 2022 Abstract Book

Virchows Archiv (2022) 481 (Suppl 1):S1–S364 13 E-PS-11-014 Odontogenic keratocysts in the setting of Nevoid Basal Cell Carcinoma Syndrome: a case report and literature review with an emphasis on CD56 immunohistochemistry analysis M. Alzamora*, J. Azevedo, J. Vaz Silva, R. Guimarães, P. Lopes, M. Jácome *IPO Porto, Portugal Background & objectives: 10-20% of odontogenic cysts are odontogenic keratocysts (OKC). Unicystic ameloblastomas are differential diagnoses of these lesions. Up to 5% of OKC are associated with Nevoid Basal Cell Carcinoma Syndrome (NBCCS), caused by a mutation in the PTCH1 gene. Methods: We present a case report of a 13-year-old patient with five multicentric and metachronous OKC. Immunohistochemical analysis for CD56 in the primary specimen was performed. Additionally, we did a review of current literature indexed on PubMed, and WHO Classification of Tumours (2017). Results: The patient was referred to our hospital four years ago for removal of a palpable mass on her lower jaw. On histology, in addition to typical OKC findings, we highlight areas of budding growth from the basal cells, daughter cysts, and remains of odontogenic epithelium. Since then, the patient has had the need to remove another 4 masses with the same characteristics. The presented case is consistent with NBCCS but the patient is yet to show any cutaneous manifestations of NBCCS, such as basal cell carcinoma. CD56 was positive, namely in the aforementioned budding growth areas. Recent studies have shown a positive correlation between expression of CD56 and syndromic OKC. Conclusion: Recurrence rates in OKC related to NBCCS are higher than in isolated cases. It is advised that when OKC are found at a young age or multiple are seen in the same patient, NBCCS should be considered. CD56 is commonly associated with unicystic ameloblastoma, which helps in the differential diagnosis with OKC. However, as found in literature, in the context of morphological and clinical findings, it may be helpful in detecting syndrome-related occurrences of OKC, such as in NBCCS. E-PS-11-015 A rare tumour of the parotid gland: lymphoepithelial carcinoma M.M. Savas*, M.H. Karabulut *Umraniye EducationTraining Hospital, Turkey Background & objectives: Lymphoepithelial carcinoma (LEC), an uncommon malignancy, occurs usually in nasopharynx and rarely in salivary glands. It is strongly associated with Epstein-Barr virus (EBV) and emerges at limited patients of the local areas as Asia or Arctic Circle. Methods: We reported a case of a Caucasian female with a LEC of the parotid gland (PG).A 48-year-old female presented with a right-sided, painful facial mass. PET/CT revealed a mass about 4.5 cm in diameter with intense FDG uptake on the right-PG and involvement of the level II unilateral cervical lymph nodes. The potential non-parotid focus was excluded. Results: She underwent total parotidectomy and ipsilateral selective neck dissection.On macroscopic examination, the mass was irregular in border and cream coloured. Microscopically, the tumours were widely infiltrative, characterized by large polygonal to spindled cells arranged in a syncytial, lattice-like network in a background of lymphoplas- macytic cells. The neoplastic cells showed an open-vesicular nuclear chromatin to a more basaloid-morphology, the latter showing hyper- chromatic nuclei and less cytoplasm. Immunohistochemistry staining revealed that the epithelial cells were reactive for panCK and p63, patchy reactive for CK 5/6, 75% strong positive for Ki67 and negative for p16. Overexpression of p53 in the epithelial cells was monitored. The case was EBV positive by ISH. Conclusion: In conclusion, LEC commonly occurs at the nasophar- ynx and rarely occurs at other sites in the head and neck region. It has a strong tendency to metastasize to the regional lymph nodes with predominant involvement of the PG and the majority of those are radiosensitive. Combination therapy with surgery and radiation is desirable. Our patient has been disease-free for 3 years after combination therapy. E-PS-11-016 Filamin-A expression in laryngeal squamous cell carcinoma and its clinical significance A. Ouban* *Alfaisal University College of Med, Saudi Arabia Background & objectives: Recent strategies to improve the overall prognosis of laryngeal squamous cell carcinomas (LSCCs) have focused on biomarkers’ discovery. Recent genomic studies reported that filamin-A is associated with metastatic LSCCs. This study was undertaken to analyse this protein’s expression in LSCCs. Methods: This study analysed the expression of filamin-A, using immunohistochemistry, in a tissue microarray of 80 cases of laryngeal cancers. Clinicopathological parameters were analysed according to filamin-A expression in the tissue microarray. Furthermore, microarray tumours expressing this protein were further categorized according to the intensity of staining. Results: A significant majority of this array’s laryngeal squamous cell carcinomas exhibited positive expression of filamin-A protein. All the filamin-A positive tumours expressed the protein in their cytoplasm. Significant correlation were found between filamin-A expression and the tumours’ grade, stage, lymph node status and metastases. A significant majority of the tumours exhibited the highest intensity of filamin-A immunohistochemical expression (IRS=12). Conclusion: A significant majority of the LSCCs of this study’s array expressed filamin-A in their cytoplasm. This expression correlated with poor prognostic parameters of LSCCs. These findings are in line with evidence seen in other head and neck cancers, suggesting an important role for filamin-A in LSCCs. E-PS-11-017 An unusual case report of carcinoma ex pleomorphic adenoma with double morphology: salivary duct carcinoma and squamous cell carcinoma M. Durzyńska*, J. Zwolinski, K. Seliga, I. Michałek, E. Bakuła-Zalewska *Department of Pathology, Maria Sklodowska-Curie National Research Institute of Oncology; MSCNRIO, Poland Background & objectives: Carcinoma ex pleomorphic adenoma (CXPA) represents carcinoma of any type arising from a primary pleomorphic adenoma (PA). CXPA is considered aggressive, affects mainly the parotid glands, and constitutes nearly 12% of all malignant tumours of the salivary glands. Methods: We report the clinical, histological, immunohisto- chemical, and genetic features of one novel submandibular- located CXPA case of 68-year-old men. The patient presented S283