Maxillary sinus metastasis from gastrointestinal stromal tumor(GIST): A rare presentation and literature review

Gastrointestinal stromal tumor (GIST) arises from the mesenchymal tissue of the gastrointestinal tract. It develops in the abdominal cavity and mostly the metastasis is limited to the liver and abdominal viscera. Metastasis beyond extra-abdominal site is rare in patients with GIST. Metastatic GIST to maxillary sinus is an extremely rare presentation and diagnostic challenge to clinicians. The treatment of metastatic GIST differs from squamous cell carcinoma of head and neck and tyrosine kinase inhibitor is the mainstay of therapy. We herein reported a case of 87-year-old lady diagnosed with recurrent GIST with metastasis to maxillary sinus and successfully treated with target therapy.