Clinicopathological Study on Posterior Fossa Tumours

Aim: To find out the occurrence of posterior fossa tumours as per the age group and sex ratio, the different clinical presentations of posterior fossa tumours in different areas, the different aetio - pathological types as per the imaging and post operative histopathological findings and find out the surgical outcomes in the post - operative period. . Material and Method: The present prospective study was conducted at Department of Neurosurgery, Nilratan Sircar Medical College & Hospital, Kolkata among 30 consecutive patients admitted with tumours of posterior cranial fossa were operated upon at the Department of Neurosurgery, NRS Medical College and Hospital, Kolkata in the period of April, 2020 to October, 2021. Patients on admission deatilesd history taking and examination was done in preset format followed by radiological investigations like CT Scan, MRI Brain. Patients operated and in the post operative period detailed history taking and examination was done in preset format followed by radiological investigations like CT Scan, MRI with follow up for any post operative complication and the histopathological result of the excised specimen. The collected data was analysed to infer results and conclusions. Results: Maximum number of patients were in the age group of 0 - 10 yr (30%) followed by 41 - 50yr (20%), 31 - 40 yr and 51 - 60 yrs 16.66% each, 21 - 30 yrs 10%, 11 - 20 yrs andgreater than60 yrs 3.33% each. Males were predominantly affected (16 cases, 60%) compared to females (12 cases, 40%). Imbalance (90%) was the predominant symptom followed by headache (83.33%), vomiting (76.66%), cranial nerve symptoms (80%), limb weakness (33.33%), bladder disturbances (6.16%), slurring of speech (13.33%). Other less common symptoms included seizures. Signs of cranial nerve involvement were found in 89.28% of cases followed by involvement of cerebellum in 82.14%, corticospinal (pyramidal) tract 60.71%, posterior column (50%) and spinothalamic tract (10.71%). Most common cranial nerve involved was CN II (63.33%) followed by CN VI (41.66%), CN VII (29.16%),, CN VIII (29.16), CN IX & X (8.33%), CN XI, CN XII. As per the imaging studies, most of the tumours were located in the cerebellum (10 cases, 33.33%) followed by fourth ventricle (8 cases, 26.66%), cerebellopontine angle (6 cases, 20%), Tentorial (4 cases, 13.33%) and brainstem (2 cases, 7.14%). As per the post - operative histopathological report, the most common tumour was by haemagioblastoma (7 cases, 23.3%) followed by, schwannoma (6 cases, 20%), low grade glioma (5 cases, 16.66%), medulloblastoma (4 cases, 13.33%), meningioma (4 cases, 13.33%), ependymoma (3 cases, 10% and metastasis (1 case, 3.33%). Low grade glioma, haemangioblastoma, schwannoma, were predominantly found in males whereas,, medulloblastoma, ependymoma, meningioma were predominantly found in females.26 patients (86.66%) having hydrocephalus underwent shunt with definitive surgery and 4 patients without hydrocephalus (13.33%) underwent definitive surgery only. Post operative complication was found in 50% (15) of cases, VII Cranial nerve palsy 33.33% (5), cerebellar hematoma 26.66% (4), CSF leak 26.66% (4), lower ccranial nerve palsy in 20% (3), meningitis 13.33% (2), pseudomeningocele in 6.66% (1). Conclusion: Chidren (0 - 10 years) are the most common group involved in posterior cranial fossa tumours. There is a male prevalence for these tumours. Cerebellum is the most common site of occurrence of these tumours. Different types of tumours have their particular age group predispositions. Symptoms of headache, vomiting, imbalance, slurring of speech, weakness are the common presentations. VII cranial nerve palsy appears here as the predominant complication and hence requires special concern intraoperatively. Complications like meningitis, pneumonia, rebleeding should be checked for at the earliest suspicion to reduce post operative mortality.