Extramedullary Relapse of Acute Lymphoblastic Leukemia Involving the Parotid Gland: A Case Report and Literature Review.

While extramedullary relapse of leukemia could occur, the parotid gland is a rare site of recurrence. Extramedullary relapse involving the parotid gland could be mistaken for other diseases. Moreover, the diagnosis of this disease is often delayed due to its rarity. Herein, we present a case of extramedullary relapse of acute lymphoblastic leukemia involving the parotid gland.