Sustained response to imatinib in patient with extraskeletal myxoid chondrosarcoma and novelKITmutation

Abstract

A 55-year-old woman presented with a 3-month history of right groin swelling, discomfort and impaired mobility. On examination, a palpable mass was noted both to the right of midline in the lower abdomen and in the right groin. MRI of the pelvis showed two masses involving the anterior abdominal wall and right groin, as well as lymph node involvement. CT imaging revealed multiple bilateral pulmonary metastases. Pathology demonstrated a myxohayline stroma morphology. Tumour was also notable for NR4A3 gene region rearrangement and mutation in KIT exon 11 at position c.1669 T>G. Based on these findings, she was diagnosed with extraskeletal myxoid chondrosarcoma (EMC). The patient has been on imatinib, a tyrosine kinase inhibitor with activity against KIT, for 3 years with stable disease. Metastatic EMC is generally treated with surgical resection and perioperative radiation therapy with adjuvant chemotherapy and is associated with poor prognosis.

Primary extraskeletal myxoid chondrosarcoma of ovary with novel KIT mutation: A case report and literature review

“…However, beside the diagnosis hall-marker of NR4A3 gene translocation, few gene variation of EMC has been noticed. As previously reported, there are only three cases EMC have KIT gene mutation [10][11][12] . Here we report the rst primary EMC of ovary and the fourth case with KIT mutation.…”

“…The 1669 T > G mutation is predicted as a gain-of-function mutation in KIT. And the patient received imatinib treatment resulted as sustained response [11] . The third case is a 69-year-old man with a st-sized mass on his left shoulder.…”