Simple SummaryIntracranial germinoma is a rare tumour of the nervous system, primarily affecting children and young adults, causing neurological and endocrinological symptoms. In this study, we found that a delayed diagnosis (>6 months after initial symptoms) leads to worse overall survival rate despite smaller sizes of the primary tumours. The time to diagnosis was shorter in patients who exhibited neurological symptoms, and bifocal lesions were associated with a significantly worse prognosis. This study emphasizes the need for timely diagnosis of intracranial germinoma, and suggests the necessity of thorough differential diagnosis in patients presenting atypical neurological and endocrinological symptoms.AbstractBackground: Intracranial germinoma is a rare malignant neoplasm of the central nervous system (CNS) that occurs in children and young adults. The aim of our study was to assess the initial manifestation of the disease, and to find differences in outcomes dependent on time of diagnosis. Methods: The study group consisted of 35 consecutive patients (adults and children) who were treated for intracranial germinoma with radiotherapy at a tertiary centre, and their data were retrospectively collected. We evaluated time from the first symptoms to diagnosis and divided patients into early and delayed diagnosis groups. Delayed diagnosis has been defined as the time from initial presentation to final diagnosis longer than six months. Results: A total of 17 (48.6%) of the patients had delayed diagnoses. Patient survival data spanned a median of six (interquartile range 3–12) years. At the time of the diagnosis, patients presented exclusively neurological symptoms in 16 (45.7%) cases, exclusively endocrinological symptoms in five (14.3%) cases, and mixed symptoms in the remaining cases (n= 14; 40.0%). Patients with neurological symptoms had shorter time (p< 0.001) from first symptoms to the final diagnosis (5.91 months) than in patients without them (19.44 months). The delayed diagnosis group presented significantly smaller tumour size (mean maximal dimension 2.35 cm) compared to early diagnosis group (3.1 cm). The 5-year and 10-year survival rates of our patients were 94.3% and 83.4%, respectively. Patients with a delayed diagnosis (n= 17) had a significantly worse (p= 0.02) 10-year OS (63%) compared to the early diagnosis group (n= 18; OS = 100%). Importantly, in five patients (14.29%), initial manifestation occurred before radiological signs of the disease. Conclusion: Our study stresses the need for timely diagnosis in intracranial germinoma, as a delay has a significant impact on the prognosis. In particular, if the tumour is small or causes exclusively endocrinological symptoms, the diagnosis may be difficult and delayed.