Objective: The objective of our study was to evaluate the frequency and surgical outcome of patients with posterior fossa lesions.Material and Methods: This observational, descriptive study was conducted in the department of neurosurgery at lady reading hospital Peshawar and PUMH Nawabshah from Jan 2014 - June 2018. A total of 163 patients were observed during the study period. All those patients who undergone surgery for intra-axial posterior fossa tumors were included in the study. We included patients of both the genders and all age groups. We took approval of the study from the hospital ethical committee and informed consent was taken from the patients or their relatives. The data was entered in a specially designed Performa. Patients’ data was analyzed using SPSS version 21.Results: We had total 163 patients during the study period who fulfilled the inclusion criteria. Most (80.4%) of the patients were in the pediatric age groups and male (57%). Age of the patients ranged from 1-65 years with the mean age 17.4 years. The most common tumors in our study were Medulloblastoma (33.1%), Ependymoma (22.7%) and Astrocytoma (19%) in descending orders. Hemangioblastoma and metastasis were seen in 6.1% cases each. The most common clinical features were headache (87.1 %) and vomiting (64.4%) cases. Most (74.8%) of the patients undergone sub-occipital tumor excision. The most common post-operative complications in descending orders were tumor bed hematoma (6.7%), wound infection (4.9%) and cerebrospinal fluid (CSF) leak (4.9%). Total mortality was observed in 12.3% cases.Conclusion: We conclude from our study that posterior fossa tumors are more common in male children. The most frequent tumors in posterior fossa are Medulloblastoma, Ependymoma and Astrocytoma. Tumors is excision (66%) is the main treatment option. The rest need CSF diversion procedures. The main post-operative complications are tumor bed hematoma, wound infection and cerebrospinal fluid leak. Mortality is high in such patients. Most patients had good and satisfactory outcome after surgery

ALI, MUMTAZ

AZAM, FAROOQ

KHAN, ZAHID

RAZA BROHI, SHAMAS

SHARAFAT, SEEMA

Pakistan Journal Of Neurological Surgery

Pak. J. of Neurol. Surg. – Vol. 23, No. 1, Jan. – Mar., 2019         -2-    ORIGINAL ARTICLE   Spectrum of Posterior Fossa Lesions: Experience at Tertiary Care Unit  SEEMA SHARAFAT, ZAHID KHAN, SHAMAS RAZA BROHI MUMTAZ ALI, FAROOQ AZAM Department of Neurosurgery, MTI, Lady Reading Hospital, Peshawar Department of Neurosurgery, PUMH, Nawabshah  ABSTRACT Objective:  The objective of our study was to evaluate the frequency and surgical outcome of patients with posterior fossa lesions. Material and Methods:  This observational, descriptive study was conducted in the department of neurosurgery at lady reading hospital Peshawar and PUMH Nawabshah from Jan 2014 - June 2018. A total of 163 patients were observed during the study period. All those patients who undergone surgery for intra-axial posterior fossa tumors were included in the study. We included patients of both the genders and all age groups. We took approval of the study from the hospital ethical committee and informed consent was taken from the patients or their relatives. The data was entered in a specially designed Performa. Patients’ data was analyzed using SPSS version 21. Results:  We had total 163 patients during the study period who fulfilled the inclusion criteria. Most (80.4%) of the patients were in the pediatric age groups and male (57%). Age of the patients ranged from 1-65 years with the mean age 17.4 years. The most common tumors in our study were Medulloblastoma (33.1%), Ependymoma (22.7%) and Astrocytoma (19%) in descending orders. Hemangioblastoma and metastasis were seen in 6.1% cases each. The most common clinical features were headache (87.1 %) and vomiting (64.4%) cases. Most (74.8%) of the patients undergone sub-occipital tumor excision.  The most common post-operative complications in descending orders were tumor bed hematoma (6.7%), wound infection (4.9%) and cerebrospinal fluid (CSF) leak (4.9%). Total mortality was observed in 12.3% cases. Conclusion:  We conclude from our study that posterior fossa tumors are more common in male children. The most frequent tumors in posterior fossa are Medulloblastoma, Ependymoma and Astrocytoma. Tumors is excision (66%) is the main treatment option. The rest need CSF diversion procedures. The main post-operative complications are tumor bed hematoma, wound infection and cerebrospinal fluid leak. Mortality is high in such patients. Most patients had good and satisfactory outcome after surgery. Keywords: Brian tumors, Craniectomy, Ependymoma, Medulloblastoma, Pilocytic Astrocytoma, Posterior fossa, Ventriculo-peritoneal shunt.  INTRODUCTION Patients with Posterior fossa tumors are critical because of decreased space available and compression of brain stem nuclei by the tumors.1 Posterior fossa tumors may be intra-axial or extra–axial. These tumors may be primary or secondary. The most common primary intra-axial posterior fossa tumors are Ependymoma, Astrocytoma and Medulloblastoma while meningioma and acoustic neuroma are the most common extra axial tumors. Primary intra-axial tumors are more common in children.2,3  The 1st large series of posterior fossa tumors was Date of Submission: 15-1-2019 Date of Printing: 15-3-2019 Seema Sharafat, et al -3-         Pak. J. of Neurol. Surg. – Vol. 23, No. 1, Jan. – Mar., 2019         http//www.pakjns.org published by cushion.4 Tumors in the posterior fossa comprise 54-70% of childhood tumors and 15 – 20% in the adult brain tumors.5 The most common intra-axial posterior fossa tumors in children are Astrocytoma while those in adults are metastasis.6  Patients with posterior fossa tumors may present with signs and symptoms of raised intracranial pressure or compression of cerebellum, brain stem and cranial nerves.  Such patients mostly, presents with headache, vomiting, ataxia and long tract signs as motor weakness.5,7 Diagnosis is made by clinical features and neuroimaging (CT scan and MRI brain). Magnetic resonant imaging (MRI) is the investigation of choice in patients with posterior fossa lesions [8-10]. The diagnosis is confirmed with histopathology report.11-13  Treatment options for posterior fossa tumors are surgical excision, shunting for hydrocephalus, and or chemo/radiotherapy. Posterior fossa surgery involves greater morbidity, mortality and the variety of complications.7,14  This study will help us to evaluate the common type of posterior fossa tumors in our population, their clinical features and management.  MATERIAL AND METHODS This observational, descriptive study was conducted in the department of neurosurgery at lady reading hospital Peshawar and PUMA Nawabshah from Jan 2014 to June 2018. A total of 163 patients who undergone surgery for intraaxial posterior fossa tumors were included in the study irrespective of their gender and age. We excluded those patients with recurrent intra-axial tumors and with extra-axial tumors (meningioma and acoustic neuroma) from our study. We took approval of the study from the hospital ethical committee and informed consent was taken from the patients or their relatives. Our patients with posterior fossa tumors were subjected either to surgical excision of tumors, ventriculoperitoneal (VP) shunt or endoscopic third ventriculostomy (ETV). Hospital record of the patients was evaluated for patients’ data regarding gender, age, clinical symptoms, radiology and operative notes. Post operatively the patients were followed up for one month for complications and mortality. All the data was entered in a specially designed Performa. Patients’ data was analyzed using SPSS version 21.  RESULTS We had total 163 patients with posterior fossa tumors who undergone surgery during the study period.  Gender Distribution Most of the patients were male. There were 93 (57%) male and 70 (43%) female patients in our study with the male to female ratio of 1.3:1.  Age Distribution Age range was 1-65 years with mean age 17.4 years. Most of the patients were in the pediatric age group as given in table 1.  Table 1:  Age distribution of patients.  Age Number of Patients % age < 15 years 131 80.4% >15 years   32 19.6% Total 163 100  Type of Posterior Fossa Tumors Are given in table 2.  Table 2:  Types of tumors.  Type of tumors Number of Patients % age Medulloblastoma    54 33.1% Ependymoma    37 22.7% Astrocytoma    31 19% Tuberculoma    11 6.7% Abscess      5 3.1% Brain stem Glioma      5 3.1% Hemangioblastoma    10 6.1% Metastasis    10 6.1% Total  163 100  Clinical Features Headache 87.1% (142), vomiting 64.4% (105) cases, decrease vision in 44.8% (73) and neurodeficit in 36.8% (60) cases.  Spectrum of Posterior Fossa Lesions: Experience at Tertiary Care Unit http//www.pakjns.org         Pak. J. of Neurol. Surg. – Vol. 23, No. 1, Jan. – Mar., 2019         -4- Surgical Treatment Almost 74.8% (122/163) of the patients undergone sub occipital resection. Gross total resection (GTR) was possible in 90 (73.8%) cases. Sub-total (partial) resection was done in 32 (26.2%) patients. Thirty six (22.1%) patients were subjected to endoscopic third ventriculostomy (ETV) and the rest 20 (12.3%) undergone ventriculoperitoneal shunt (VP shunt).  Post-operative Mortality and Complications We observed total mortality in 12.3% (20) cases within 1 month of surgery. The post-operative complications are given below in table 3.  Table 3:  Post-operative complications.  Post-operative Complication No of Cases % age Cerebral edema   6 3.7% Hydrocephalus   5 3.1% Hematoma 11 6.7%  CSF leak   8 4.9% Meningitis   5 3.1% Wound infection   8 4.9% Total 43 26.4%  DISCUSSION Posterior fossa tumors are the most devastating forms of human illnesses. These tumors are significant because of the associated morbidity and mortality. In addition the surgical excision of these tumors has always been a challenge.1,7  It has been reported that posterior fossa tumors are more common in men.1,15,16 In a study there were 59.5% male and 40.5% were female.1 We also observed in our study that most of our patients were men. However, some studies had reported that posterior fossa tumors are common in female than male population.17 The reason that posterior fossa tumors are common in men is not clear, but may be because of hormonal difference.  Posterior fossa tumors are more common in children in the 1st decade of life.15,18,19 The most common posterior fossa tumors in children are Pilocytic Astrocytoma, Ependymoma and Medulloblastoma. While in adults the most common intraaxial posterior fossa tumors are metastasis.2,7,20,21 In a study of posterior fossa tumors in children it was reported that Medulloblastoma were in 36% cases, Astrocytoma in 28% cases, brain stem Glioma in 9% patients and Ependymoma in 4% patients.15 In another study in 81% cases, posterior fossa tumors were observed in 81% in the 1st decade of life 1. Yamauchi et al17 Studied 27 patients with posterior fossa tumors, of which 22.2% (6/27) were Pilocytic Astrocytoma, 18.5% (5/27) were high grade Gliomas, Medulloblastoma were 11.1% (3/27), Hemangioblastoma (22.2% (6/27), metastatic tumors 11.1% (3/27) and malignant lymphoma in  14.8% (4/27). In our study, we have almost the same results. In our study, these tumors were more common in pediatric age group in 80.4% cases. The most common tumors in our study were Medulloblastoma (33.1%) followed by Ependymoma (22.7%) and Astrocytoma (19%). We had metastasis and Hemangioblastoma each in 6.1% cases and brain stem Gliomas in 3.1% cases.  Patients with Posterior fossa tumors have raised intracranial pressure and compression of surrounding brain structures as the brain stem and cerebellum. Therefore the most common symptoms are headache (80-92%) and vomiting (60%) followed by gait disturbance.11 In another study, patients with headache (54%), vomiting (45.9%), seizures (27%) and cranial nerve palsy (45.9%).22. Here again our results are comparable to other studies. We had headache (87.1%) and vomiting (64.4%) the most common clinical presenting features.  The main aim of surgical excision of posterior fossa tumors is safe total removal. Prognosis is good in patients with total excision. However, total excision is not always possible because of invasion of vital structures as brain stem by the tumors.1 In our study gross total removal was possible in almost 74% cases. Different studies have various reports. In a study of 50 cases gross total removal was done in 91.4% cases. Here we had lesser complete removal of tumor. This may be because of late presentation of our patients. By the time patients present to us have wide extension of lesions.  Posterior fossa tumors are known for their surgery related mortality and morbidity. These postoperative complications may be dangerous and sometimes fatal. Dubey et al23 studied 500 patients for posterior fossa complications and observed post-operative mortality and morbidity in almost 45.6% cases. In their study the Seema Sharafat, et al -5-         Pak. J. of Neurol. Surg. – Vol. 23, No. 1, Jan. – Mar., 2019         http//www.pakjns.org most common complications were meningitis (9.2% cases) and wound infection (7% cases). In their study total mortality was in the 2.6% (13/500) cases.  In our study, we observed total postoperative complications in 26.4% cases and the most common complications were tumor bed hematoma in 6.7% cases, followed by wound infection and cerebrospinal fluid leak each in 4.9% cases. Meningitis was noted in 3.1% of our cases. Here our total complications were less than what Duby et al observed in their study, however, our mortality rate (12.3%) was higher than their study. The higher mortality in our study is not clear, but may be because of late presentation of the patients.  After surgery the patients were treated according to the histopathology report and age of the patients. Those with age less than 3 years and malignant lesions were sent for chemotherapy only. The rest with malignant lesions were subjected to chemoradiation.  CONCLUSION We conclude from our study that posterior fossa tumors are more common in male children. The most frequent tumors in the posterior fossa are Medulloblastoma, Ependymoma and Astrocytoma.  Tumors excision (66%) was the main treatment option. The rest needed CSF diversion procedures. The main post-operative complications are tumor bed hematoma, wound infection and cerebrospinal fluid leak. Mortality is high in such patients. Most patients had a good and satisfactory outcome after surgery.  Additional Information Disclosures:  Authors report no conflict of interest.  Human Subjects:  Consent was obtained by all participants in this study.  Conflicts of Interest:  In compliance with the ICMJE uniform disclosure form, all authors declare the following:  Payment/Services Info:  All authors have declared that no financial support was received from any organization for the submitted work.  Financial Relationships:  All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work.  Other Relationships:  All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work.  Address for Correspondence: Dr. Zahid khan Consultant Neurosurgeon Department of Neurosurgery, MTI, Lady Reading Hospital, Peshawar Cell no: 03359345434 Email: neurosurgeonzahid@yahoo.com  ROLE OF AUTHORS Dr. Seema Sharafat. Paper Writing. Dr. Zahid Khan. Data Collection. Dr. Shamas Raza Brohi, Literature Search. Dr. Mumtaz Ali. Overall Supervision Dr. Farooq Azam. Tables and Graphs.  REFERENCES 1. Prasad KSV, Ravi D, Pallikonda V, Raman BVS. Clinico-pathological study of pediatric posterior fossa tumors. J pediatric Neurosciences, 2017; 12 (3): 245-250. 2. Grossman R, Ram Z. Posterior Fossa Intra-Axial Tumors in Adults. World Neurosurg. 2016; 88: 140-5. 3. Barkovich AJ. Pediatric neuroimaging. Philadelphia. Lippincott Williams Wilkins, C 2005: ISBN. 0781757665. 4. Cushing H. Experience with cerebellar medulloblastoma: Critical review. Acta pathol microbial immunol scand. 1930; 7: 1-86. 5. O'Brien DF1, Caird J, Kennedy M, Roberts GA, Marks JC, Allcutt DA. Posterior fossa tumours in childhood: evaluation of presenting clinical features. Ir Med J. 2001 Feb; 94 (2): 52-3. 6. Shih RY, Smirniotopoulos JG. Posterior Fossa Tumors in Adult Patients. Neuroimaging Clin N Am. 2016; 26 (4): 493-510. 7. Muzumdar D, Ventureyra EC. Treatment of posterior fossa tumors in children. Expert Rev Neurother. 2010 Apr; 10 (4): 525-46. 8. Brandão LA, Young Poussaint T. Posterior Fossa Tumors. Neuroimaging Clin N Am. 2017; 27 (1): 1-37. 9. Poretti A., Meoded A., Huisman T.A. Neuroimaging of pediatric posterior fossa tumors including review of the literature. J Magn Reson Imaging, 2012; 35 (1): 32–47. 10. Borja M.J., Plaza M.J., Altman N., Saigal G. Spectrum of Posterior Fossa Lesions: Experience at Tertiary Care Unit http//www.pakjns.org         Pak. J. of Neurol. Surg. – Vol. 23, No. 1, Jan. – Mar., 2019         -6- Conventional and advanced MRI features of pediatric intracranial tumors: supratentorial tumors. AJR Am J Roentgenol. 2013; 200 (5): W483–W503. 11. Raybaud C, Ramaswamy V, Taylor, Laughlin. Posterior fossa tumors in children: developmental anatomy and diagnostic imaging. Childs Nerv Syst. 2015; 31( 10): 1661-76. 12. Wolpert S.M. Mosby Year Book; St. Louis, MO. MRI in pediatric neuroradiology, 1992. 13 Kleihues P., Burger P.C., Scheithauer B.W. Springer-Verlag; Berlin. Histological typing of tumors of the central nervous system, 1993. 14. Allen J.C. Siffert J. Contemporary Chemotherapy Issues for Children with Brainstem Gliomas. Pediatr Neurosurg. 1996; 24: 98–102. 15. May PL, blaser SI, Hoffman HJ, Humphreys RP, Harwood-Nash DC. Benign intrinsic tectal tumors in children. J Neurosurg. 1991; 74: 867-71. 16. Smoll N.R., Drummond K.J. The incidence of medulloblastomas and primitive neurectodermal tumours in adults and children. J Clin Neurosci. 2012; 19 (11): 1541–1544. 17. Yamauchi M, Okada T, Yamamoto A, Fushimi Y, Arakawa Y, Miyamoto S et al. Differential diagnosis of posterior fossa brain tumors. Medicine (Baltimore), 2017 Aug; 96 (33): e7767. 18. Albright AL, Guthkelch AN, Packer RJ, Price RA, Rourke LB. Prognostic factors in pediatric brain-stem gliomas. J Neurosurg. 1986; 65: 751-5. Back to cited text no. 12. 19. Sutton L, Schut L. Cerebellar astrocytomas. In: McLaurin R, Schut L, Venes, et al., editors. Pediatric Neurosurgery: Surgery of the Developing Nervous System. Philadelphia, PA: WB Saunders Co.; 1989. p. 338-46.  Back to cited text no. 14. 20. Spennato P, Nicosia G, Quaglietta L, Donofrio V, Mirone G, Di Martino G et al. Posterior fossa tumors in infants and neonates. Childs Nerv Syst. 2015; 31 (10): 1751-72. 21. Rx: Badri M, Chabaane M, Gader G, Bahri K, and Zammel I. Cerebellar metastasis of gastrointestinal stromal tumor: A case report and review of the literature. Int J Surg Case Rep. 2018; 42: 165–168. 22. Cheldiev BZ et al. Radicalness and complications of repeat surgery for malignant neuroepithelial tumors of the posterior cranial fossa in children. Zh vopr neirokhir Im NN burdenko/ 2018; 82 (5): 104-110. 23. Dubey A, Sung WS, Shaya M, Patwardhan R, Willis B, Smith D, Nanda A. Complications of posterior cranial fossa surgery—an institutional experience of 500 patients. Surgical Neurology, 2009; 72 (4): 369-375.    Date of Submission: 15-1-2019 Date of Printing: 15-3-2019    

Spectrum of Posterior Fossa Lesions: Experience at Tertiary Care Unit

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Spectrum of Posterior Fossa Lesions: Experience at Tertiary Care Unit

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Pakistan Journal Of Neurological Surgery