When infection meets malignancy: A case report of a rare collision lesion of leiomyosarcoma and amebic cyst in the gluteal region.

We report on a 61-year-old male patient who presented with a chronic left buttock mass and pain. Initial MRI revealed a multiloculated mass in the gluteal region. The mass was percutaneously drained after initial microbiology analysis identified it as an isolated amebic cyst. However, the patient showed only partial improvement after 1 month of drainage and conservative management. Subsequently, surgical resection of the mass was performed. Histological examination of the resected tissue revealed an exceptionally rare diagnosis: a collision lesion of a leiomyosarcoma and an amebic cyst.