Long-lasting stable disease with mTOR inhibitor treatment in a patient with a perivascular epithelioid cell tumor: A case report and literature review.

Perivascular epithelioid cell tumor (PEComa) of the small intestine is extremely rare, and there is no established treatment at the present time. In 10% of patients with PEComas, genetic alterations of tuberous sclerosis complex have been reported. These genetic alterations activate mechanistic target of rapamycin (mTOR) in AMP-activated protein kinase and Ras/mitogen-activated protein kinase pathways, resulting in high mTOR activity. Since 2007, several cases of treatment with mTOR inhibitors in advanced PEComa have been reported. The current study presents the case of a patient with small bowel PEComa that metastasized to the brain and lungs. Following resection of the brain metastasis, the patient was treated with everolimus, a mTOR inhibitor, resulting in improvement if the patient's quality of life and a long period of stable disease. In conclusion, the use of mTOR inhibitors as a first-line treatment option in advanced PEComa patients appears to be reasonable, according to the increasing evidence from data observed from reported cases with this rare malignancy.