Perianal embryonal rhabdomyosarcoma: A case report.

Perianal embryonal rhabdomyosarcoma (ERMS) is a rare disease with a poor prognosis. There are few reported cases of this disease, and specific clinical manifestations are lacking; therefore, making an early diagnosis before surgery is challenging. In November 2014, a 30-year-old man was admitted to Xiaoshan Affiliated Hospital of Wenzhou Medical University due to severe left perianal pain. Ultrasonography revealed a multilocular perianal abscess, and an emergency perianal abscess incision and drainage were performed. However, pathology combined with immunohistochemistry confirmed an ERMS. The patient did not receive postoperative radiotherapy or chemotherapy and died of multiple metastases and multiple organ failure 6 months later. Perianal ERMS is highly malignant and rare, and can easily be misdiagnosed as a perianal abscess. Clinicians must enhance their knowledge and improve preoperative diagnostic tests to prevent misdiagnoses.