ECP 2022 Abstract Book

Virchows Archiv (2022) 481 (Suppl 1):S1–S364 13 E-PS-11-024 Mandibular osteosarcoma: a retrospective study with review of the literature S. Makni*, Y. Loukil, M. Triki, I. Saguem, C. Chaari, W. Ghribi, T. Boudawara, M. Mellouli *Habib Bourguiba University Hospital, Tunisia Background & objectives: Osteosarcomas are the most common bone sarcomas. They are preferentially located in the long bones of the limbs. Mandibular localization is rare, only a few cases have been reported in the literature. Methods: we present a study of 6 cases diagnosed in the depart- ment of pathology at the CHU Habib Bourguiba in Sfax over a period of 10 years (2012-2021) Results: The mean age was 40 years (extreme: 24-54). Four of the patients were men (sex-ratio:2). A history of irradiation was noted in two cases. All tumours were located in the body of the mandible. The average tumour size was 6.5cm (extreme: 3.5-10 cm), the histological type was chondroblastic osteosarcoma in 5 cases and osteoblastic in one case. Four out of six patients had received neoadjuvant chemotherapy. The histological evaluation of the therapeutic effect showed a stable calcified appearance of the tumour in one case and tumour necrosis rates of 20%, 30% and 40% for the others. Surgical margins were positive in 5 cases. Conclusion: Mandibular osteosarcoma is a rare tumour; the most common histological type is chondroblastic, then osteoblastic and fibroblastic osteosarcoma with frequencies of 48%, 29% and 23% respectively. Its prognosis depends mainly on the quality of surgical excision. A surgical margin of at least 1 cm was recommended to avoid recurrence. Neoadjuvant chemotherapy prevents rapid disease progression and reduces tumour size. E-PS-11-025 Benign smooth muscle proliferations of the tongue. Retrospec- tive cohort study of a case series in a 31-year single institution M. Bronte Anaut*, J. Arredondo Montero, A. Larrea, G. Aísa Rivera, A. Echegoyen Silanes, J.M. Elizalde Eguinoa, P. Fernan- dez Seara *Complejo Hospitalario de Navarra, Spain Background & objectives: Leiomyomas are benign spindle cell tumours. Less than 1% are seen in the head and neck area. The defini- tive diagnosis is established upon histology. The differential diagnosis includes benign and malignant soft tissue tumours that may arise in the tongue. Methods: We performed a retrospective search for cases signed- out as leiomyoma or hamartoma in the pathology database between the time interval of January 1990 and December 2021. A total of 5 cases were identified for which slides and blocks were avail- able. The medical records were reviewed. All lesions located on the tongue but with different diagnosis were excluded from this analysis. Results: 4 patients were women. Median age was 65 years (2 months–89 years). Three patients had complaints of a slow-growing and painless mass. One patient referred occasional bleeding. At birth, the infant had no anatomical alterations of craniofacial structures or midline defects. On physical examination, the lesion was located: dorsal lingual surface (N=2), tip of tongue (N=2) and right lateral border (N=1). Surgical resection of all lesions was performed. Histologically we had three different variants of benign smooth muscle proliferations: angioleiomyoma (N=3), non- vascular leiomyoma (N=1) and leiomyomatous hamartoma (N=1). During follow-up, there was no evidence of local recurrence or the appearance of leiomyomas in other body locations. Conclusion: Leiomyomas are benign lesions in which surgical resection is curative in most cases. Therefore, despite being infre- quent lesions in the oral cavity, compared to other anatomical loca- tions, it is necessary to think about them when the pathologist is faced with a soft tissue lesion in this location, relying whenever necessary on complementary immunohistochemical studies. E-PS-11-026 Diagnostic challenge: rare secretory carcinoma subtype identi- fied in a parotid carcinoma ex pleomorphic adenoma I. Mergeanu*, O.M. Patrascu, A. Voinovici, M. Sajin, M. Costache *University Emergency Hospital Bucharest, Romania Background & objectives: Salivary gland secretory carcinomas rep- resent a relatively new entity, whereas carcinomas ex pleomorphic adenoma account for a modest percentage of salivary glands tumours. Therefore, the adjoining of the two appears to be a rather shy occur- rence in practice. Methods: Our Department of Pathology received a total parotidectomy specimen, samples from which were fixed with 10% buffered formalin and processed by conventional histopathological methods, using paraffin embedding, sectioning and Haematoxylin–Eosin (HE) staining, as well as PAS and mucicarmine staining. Afterwards, the sections were deparaffinized and prepared for immunohistochemical staining, using the following markers: CK7, p63, S100, GATA3 and Ki67. Results: We report the case of a 51-year-old male with a 15-year history of an asymptomatic mass in the parotid region. Gross examination revealed a spheric, white, firm tumour. Microscopic examination identified a heterogenous, encapsulated mass present- ing ductoglandular and solid structures, embedded in fibro-hyalin stroma. Tumoural cells exhibited cito-nuclear atypia, eosinophilic cytoplasm, mucous cells and intraluminal secretions that stained positive for PAS and mucicarmine. Tumoural cells stained positive for CK7, S100, GATA3, negative for p63, with Ki67 positive in 10% of them. Pleomorphic adenoma looking nodules were identi- fied adjacent to the malignant proliferation. Thus, the diagnosis of carcinoma ex-pleomorphic adenoma, secretory carcinoma subtype with focal high-grade areas has been established. Conclusion: Secretory carcinoma of the salivary glands or mammary analogue secretory carcinoma is a relatively new and rare entity that needs additional special and immunohistochemical stains to differentiate it from the multitude of histological subtypes. The occurrence of this subtype in a rather infrequent carcinoma ex-pleomorphic adenoma further advocates for the need to carefully assess all histological and immunohistochemical characteristics, given the poor prognosis of the high-grade variant and treatment options. E-PS-11-027 Unique initial manifestation of salivary gland adenoid cystic carcinoma as a solitary liver metastasis D. Myoteri, E. Stoupi, J. Koskinas, D. Tiniakos* *Department of Pathology, Aretaieio Hospital, Medical School, National and Kapodistrian University of Athens, Greece Background & objectives: Liver metastases from salivary gland tumours are rare and presenting as the initial manifestation of disease is extremely rare with only four cases reported to date. Methods: A 68-year-old man discovered elevated GGT and alka- line phosphatase during routine laboratory tests. He was further S286