ECP 2022 Abstract Book

Virchows Archiv (2022) 481 (Suppl 1):S1–S364 13 3/5, we observed acquisition of new chromosomal abnormali- ties. 1 to 19 chromosomes were affected, in varying numbers of chromosomes with an average of 5 to 11 chromosomes per tumour altered. Conclusion: Until now, evidence of rabdoid morphology qualify for a correct diagnosis alone of MR, nevertheless misdiagnosis can be present specially when rabdoid cells are scatter and no other atypical histological characteristic is present. We have established 2 profiles of chromosomal alterations (one with chromosomal losses and one with losses combined with gains of several genetic regions).The most frequent alteration it was the loss of one chro- mosome 22 (monosomy). Genomic sequencing could help to the graduation of these tumours. PS-23-004 Grade 2 meningiomas: a retrospective study of 30 cases at a single institution M. Mellouli*, S. Graja, F. Kolsi, M. Triki, N. Gouiaa, T. Bouda- wara, R. Kallel *Department of Pathology, Habib Bourguiba University Hospital, Sfax, Tunisia Background & objectives: Meningiomas present a broad morphologi- cal spectrum. Grade 2 meningiomas (G2M) are aggressive tumours associated with a high recurrence rate. In this study, we aimed to evalu- ate the epidemiological and histopathological features of G2M in our department. Methods: This retrospective study included 30 cases of G2M diagnosed during 5 years (January 2012-December 2017) at our department. A review of the slides was performed and the menin- giomas were reclassified according to the fifth edition of the WHO Classification of Tumours of the Central Nervous System (WHO CNS5) published in 2021 Results: Our study included 12 men and 18 women (Sex ratio=0.66). The mean age was 56.2 years. The most common symptom was an intra-cranial hypertension. The main localization was the supra-tentorial region (93%). Neurosurgical resection was performed in all cases. Gross-total resection was achieved in 16 cases (53.3%). Histopathologic examination concluded to an atypi- cal meningioma (AM) in 28 cases (93.4%), a clear cell meningioma (CCM) in one case (3.3%) and a rhabdoid meningioma (RM) in one case (3.3%). Ki67 proliferation index was determined in 12 cases. The value varies between 2 and 20%. Recurrence was noted in 6 cases (20%). The progression-free survival and overall survival were 73.3% and 86.7% respectively. Conclusion: It is now emphasized that the criteria defining atypi- cal or anaplastic (ie, grade 2 and 3) meningioma should be applied regardless of the underlying subtype. As in prior classifications, chordoid and CCM are noted to have a higher likelihood of recur- rence than the average WHO grade 1 meningioma and have hence been assigned to WHO grade 2. G2M exhibit a high tendency to relapse with up to 29-52% recurring. The recurrence rate in our study was 20%. PS-23-005 Epidemiologic profil of primary cerebellar tumour in the south of Tunisia M. Mellouli*, S. Graja, F. Kolsi, M. Triki, S. Charfi, C. Kammoun, T. Boudawara, M. Manai *Department of Pathology, Habib Bourguiba University Hospital, Sfax, Tunisia Background & objectives: There are several reports regarding the epidemiology of brain tumours. However, little is known about the profile of primary cerebellar tumours (PCT). We report the results of a retrospective study of PCT in an institution of the south of Tunisia. Methods: We included in our study all cases of PCT diagnosed at our department during 11 years (January 201-December 2020). The tumours were classified according to the fourth edition of the WHO Classification of Tumours of the Central Nervous System (WHO CNS) published in 2016. Results: Forty-six cases of PCT were included. The average age was 19 years (1-74 years). 45.6% of patients were under 18 years old and 54.4% were over 18 years old. Tumours were located in cerebellar hemisphere in 21 cases (70%), in the vermis in 6 cases (20%) and vermi-lobular in 3 cases (10%). In paediatric popula- tion (PP), the sex ratio was 1.1 while in adult population (AP) it was 0.92. Medulloblastoma was the most common histological type for both PP and AP (61.9% and 40% respectively). Pilocytic astrocytoma (PA) represented the second most frequent tumour in PP (38.1%). In AP, haemangioblastoma and PA were diagnosed in 8 and 3 cases respectively. Conclusion: PCT represent with brainstem tumours 10% of all tumours of the CNS and are frequently encountered in paediatric population. Medulloblastoma and PA are the two most common tumours in childhood as reported in our study. According to the lit- erature, the most common tumour in adults is haemangioblastoma. Contrary to what is reported, our study showed a high proportion of medulloblastoma in adults. PS-23-006 Analysis of the procedure for extracting, sending and receiving the muscle biopsy. Knowledge, attitudes and practices of the professionals involved F. Leiva-Cepas*, J. Osuna Soto, M.J. Gálvez Medina, I. Sánchez Ramírez, J. Cámara Pérez *University Hospital "Reina Sofía", Spain Background & objectives: The knowledge of professionals related to muscle biopsy has not been estimated at present. The objective of this work is to evaluate the knowledge, attitudes and practices of medical specialists and those in training regarding the muscle biopsy procedure. Methods: Observational, descriptive, cross-sectional and multi- centre study (Provincial hospitals of the Andalusian Health Ser- vice. Participants: Specialist physicians and in training randomly selected by sending an anonymous survey, previously validated, by email that included items on the sending of the sample, the excision of the sample, its orientation, volume, etc. . A descriptive, bivari- ate and multivariate statistical analysis was performed (p <0.05). Results: Participants: 22 professionals completed the survey (72.7% -16- neurosurgeon; 18.2% -4- plastic surgeons, 4.5% -1- pathologist and 4.5% -1- neurologist. 50% were resident intern specialists. 81.8% -18- were women. 66% of those surveyed did not know the volume of tissue to send to the Pathological Anatomy (AP) service. Only 18.2% informed AP about the shipment. 66.7% considered that they were not well educated about the procedure. 73% did not reference the distal or proximal portion of the sample. 10.1% personally sent the sample to the PC service for its correct reception. Conclusion: Knowledge and practices about the muscle biopsy procedure in the subjects analysed are scarce, so specific training strategies to increase their knowledge and improve their attitude and skills regarding this procedure should be considered for actual incorporation into the plans training, to avoid diagnostic delays, inadequate handling of the sample and unnecessary reinterventions. S162