Metastatic spindle cell tumor in sacrum

Spindle cell tumours metastatic to bone are rare. A gastrointestinal stromal tumor (GIST) with spindle cell histology is one such tumour that may rarely metastasize to bone and pose great diagnostic or therapeutic challenge for the clinicians. Their symptoms are minimal in the early stage and may go unnoticed before being detected. At the time of presentation, the tumor often metastasizes to other parts of the body, rarely to bone. GISTs are defined as spindle cell, epitheloid, or occasionally pleomorphic mesenchymal tumors of the gastrointestinal tract, which express the KIT protein (CD117), and/or DOG1.Cytological and histological features of metastatic GIST are variable. We present here a rare case of metastatic spindle cell tumour (without clinical evidence of primary) involving sacrum with histopathological & immunohistochemical features of GIST.