Extra Gastrointestinal Stromal Tumour (EGIST) of Chest Wall Detected on 18F-FDG PET/CT: A Case Report and Brief Review of Literature

Gastrointestinal stromal tumors (GIST) are rare tumors accounting for less than 1% of primary neoplasia of the digestive tract. They can also occur outside the GIT, where they are called extra gastrointestinal stromal tumors (EGIST), which are extremely rare tumors. GISTS and EGISTS have similar histo-pathological and molecular profiles. Though these are known to be FDG avid, some of the atypical GISTS can be FDG negative or only minimally FDG avid. Here, an unusual case of a 57-year-old female with FDG avid solitary chest wall mass is presented, which after biopsy and immune-histochemistry was proven as EGIST. She underwent en block resection of the tumor and is presently on adjuvant treatment with Imatinib mesylate. This case report highlights the importance of considering EGIST as a differential diagnosis of a solitary chest wall mass and the utility of 18FFDG PET/CT in its management.