Premalatha Pidakala1, Renuka Venkata Inuganti2, Chaitra Boregowda3, Atchyuta Mathi4, Shalini Lakhineni5
Tumours of central nervous system (CNS) are of varied histogenesis and show divergent lines of differentiation and morphological features. These tumours show specific predilection for age and sex groups, more commonly than of tumours of other systems. Though tumours of glial tissue are more common, other tumours of neural, ependymal and meningeal origin are not uncommon. Metastatic disease is the common encounter in elderly. Tumour diagnosis is not always straight forward as many non-neoplastic lesions and reactive proliferations mimic tumours. Immunohistochemistry may help in problematic cases and thus can be used as an adjuvant tool in the diagnosis of such cases in addition to the routine histopathological staining methods. An accurate histological diagnosis is of extreme importance in these sites as exact diagnosis helps in proper management and favourable clinical outcome.
MATERIAL & METHODS
This study is on a retrospective and prospective basis in our institution from January 2011 to January, 2016. Our institute is a tertiary care center attached to a medical college catering to the needs of a rural based population. During this period, a total of 717 central nervous system tumour specimens were received and diagnosed based on examination of Haematoxylin and Eosin stained sections of formalin fixed and paraffin embedded specimens. Immunohistochemical markers (IHC) were applied in selective cases for an accurate diagnosis and a number of rare cases were diagnosed based on morphology and IHC marker studies.
Age and sex incidence and anatomic distribution of various tumours were studied. In adults, meningiomas occurred most frequently in the present study followed by nerve sheath tumours, astrocytomas, metastatic deposits, glioblastomas and pituitary adenomas. Embryonal tumours occurred frequently in children. Other rare tumours identified are amyloidogenic pituitary adenoma, central neurocytoma, glioneuronal tumour with neuropil-like islands, ganglioglioma, large cell medulloblastoma, rhabdoid and secretory meningioma, immature teratoma and gliosarcoma. Grading of the tumours was done according to the revised World Health Organization criteria.
In this study, we discuss the process of establishing accurately the diagnosis of central nervous system tumours including spinal tumours, with emphasis on rare tumours encountered and how IHC helped in the diagnosis.