Recurrence of childhood acute lymphoblastic leukemia presenting as a tumor of the middle ear: a case report.

Extramedullary relapse of childhood acute lymphoblastic leukemia most commonly occurs in the central nervous system or in the testes. Otologic involvement is very rare and has only been reported as an autopsy finding.,We describe the case of a 5-year-old girl with CD10 positive acute lymphoblastic leukemia (ALL) who developed an isolated otologic relapse 18 months after the initial diagnosis of ALL.,This otologic relapse presented as an atypical otitis media related to a mass of the middle ear. The leukemic infiltration of the middle ear was demonstrated by histologic examination. A cytogenetic change characterized by the occurrence of t(1;19)(q23;p13) was observed in the leukemic cells from the middle ear, and the t(1;19) molecular fusion transcript E2A-PBX1 was detected in the bone marrow by polymerase chain reaction.,The ear is an exceedingly rare site of relapse in children with acute lymphoblastic leukemia. Molecular analysis demonstrates that such an extramedullary relapse can represent an early manifestation of systemic relapse.