Clinical and cytohistomorphological evaluation of peripheral nerve sheath tumours with special reference to immunohistochemical diversity in a tertiary care hospital

Abstract

Peripheral Nerve Sheath Tumours (PNST), though have a frequent prevalence, are diagnostically challenging. There is a wide spectrum of lesions ranging from benign entities like neurofibroma, Schwannoma, perineurioma to malignant entities like malignant peripheral nerve sheath tumours (MPNST), malignant granular cell tumour and malignant perineurioma. Since there is an overlap with other spindle and round cell tumours, IHC and molecular studies are needed to provide a clear distinction between different tumour types. It was a 5 years observational study (3 years retrospective and 2 years prospective) conducted in the Department of Pathology, JNMCH, AMU from 2015-2020. . History and relevant clinical findings were retrieved from the archives of both the Histopathology and Cytopathology Lab. Imprints as well as FNA smears were included from Cytopathology Lab and biopsies and resection specimen from Histopathology Lab. Immunohistochemistry was applied wherever necessary. A total of 82 cases were diagnosed over a 5 year period out of which 70 were benign and 12 malignant. Male preponderance was seen. Benign tumours comprised mostly of Neurofibroma and Schwannoma and there were 12 cases of MPNST. Correlation was established between Cytopathological and Histopathological findings and IHC, mostly S100 proved useful in differentiating it from other malignant spindle cell tumours. The differential diagnoses of these tumours has always posed a problem given their monotonous appearance and clinical overlap. This study, therefore, aims to analyse the diverse morphological features of Peripheral Nerve Sheath Tumours in the light of cytopathological and histopathological findings and immunohistochemistry.