Temporary Spontaneous Remission of Adult Acute Lymphoblastic Leukemia Associated with Scrub Typhus Infection

Acute lymphoblastic leukemia (ALL) in adult patients usually poses a treatment challenge with intensive chemotherapeutic agents. Prognosis is worse in comparison to pediatric patients owing to disease biology and associated comorbidities. Spontaneous remission of ALL is rare and warrants close follow-up for progression.

Herein, we report the case of a male in his 40s initially admitted for febrile illness with pancytopenia; later, his serology was positive for scrub typhus infection, and he was managed for the same with antimicrobials. Due to the persistence of pancytopenia, a bone marrow examination revealed 14% blasts, which were confirmed as B lymphoblasts on flow cytometry. Molecular workup, including cytogenetic and next-generation sequencing, was done. There was no indication for treatment, and the hemogram subsequently improved spontaneously, with normalization of blood count parameters.

The patient was kept under close follow-up as an outpatient with clinical examination and hematological parameters. Five months later, the patient was diagnosed with ALL and, unfortunately, died during therapy.