P20.06.B CHOROID PLEXUS TUMORS IN ADULT: RETROSPECTIVE MONO-INSTITUTIONAL STUDY

Abstract BACKGROUND Choroid plexus tumors (CPT) are rare entities, mainly affecting childhood, including three grade subtypes. MATERIAL AND METHODS A mono-institutional retrospective series of adult CPT patients was collected. The database contains demographic and clinical details, diagnostic (radiological and histological/molecular), therapeutic, recurrence information, and survival data. RESULTS We described twenty-four adult CPT, with a median age of 43.29 years [Interquartile range (IR) 37.31-53.30]. Clinical onset (n=20/24) included cerebellar signs (n=11), intracranial hypertension signs (n=8), cranial nerves impairment (n=5), seizures (n=1), spinal signs (n=1) (multiple symptoms in some patients). Remarkably, in 17% the radiological detection was occasional.The tumors were mostly located in the ventricular system at first diagnosis: 79.2% were infratentorial, but any other locations can occur, including the spine (one case); meningeal involvement was present in one case. Only one case presented a pre-surgical hydrocephalus. CPT histological grade ranged from grade 1 (n=17), grade 2 (n=6), and grade 3 (n=1). TERTp mutations were detected in 17.6% (n=3/17). TP53 mutation in 5.9% (n=1/17). Complete resection was achieved in n=16/24 (66.7%), gross-total resection in n=3/24 (12.5%), partial resection in n=3/24 (12.5%), biopsy in one case, and no information on surgery extension in one case. 76% of the cases (n=16/21) experienced clinical worsening suddenly after surgery for different reasons, and mostly gradually recovered. Adjuvant therapy was performed only for grade 2 and 3 tumors, and included conformational radiotherapy (RT) in one disseminated grade 2 and in one grade 3 case. At recurrence, surgery, RT, and chemotherapy had been considered. The median Overall Survival from surgery was 108.1 months [IR 62.5-143.4]. CONCLUSION We could confirm that CPT can occur in adults, and are mostly grade 1 tumors and located in the ventricular system. The surgical approach is the gold standard, although a substantial number of clinical worsening occurred, but often transient. Adjuvant treatment is limited to higher grade CPT; however, no consensus has already been achieved about adjuvant therapy. FUNDING RRC Italian Ministry of Health