Extrarenal rhabdoid tumour of axillary soft tissue: a diagnostic challenge resolved by immunohistochemistry

Extrarenal rhabdoid tumour of soft tissue in children is a rare tumour associated with poor prognosis. It is a heterogeneous group of aggressive tumours with distinct histopathological and immunohistochemistry findings. The tumour is characterised by diffuse proliferation of rhabdoid cells with hyaline like inclusion bodies. Defining feature is aberration of INI1/SMARCB1 gene located at chromosome 22q11.2. We report one such rare case in a female infant presenting as left axillary mass.