Gastrointestinal stromal tumor and isolated anterior tibial muscle metastasis as first recurrence

In the presented case, we report gastrointestinal stromal tumor (GIST) in a patient using adjuvant imatinib in whom isolated metastasis to anterior tibial muscle as first recurrence was diagnosed. A 66-year-old woman was diagnosed with GIST on October 2012 and was followed up with adjuvant imatinib until June 2014. In this time, there was a nodular and fixed lesion with 1.5-2 cm of diameter in right lateral pre-tibial area. The lesion was resected, and it was reported as GIST metastasis by pathologist. GIST metastasis to muscle under knee is a generally unexpected area for any tumor metastasis. In modern treatment era, due to the increasing survival of the patients with GIST using targeted therapy, the metastatic pattern and behavior of GIST may be changing