Oral–visceral iatrogenic Kaposi sarcoma following treatment for acute lymphoblastic leukemia: a case report and review of the literature

BACKGROUND: There have hardly been any reported cases of children presenting with Kaposi sarcoma as a second malignancy following treatment for acute lymphoblastic leukemia outside a transplant setting. CASE PRESENTATION: We report a case of a 5-year-old boy of Bantu origin, which, to our knowledge, could be only the second reported case of oral–visceral Kaposi sarcoma after acute lymphoblastic leukemia treatment. The patient presented with a 1-month history of progressive, non-painful, soft tissue oral mass, 1 month after completing treatment for high-risk acute lymphoblastic leukemia. He was successfully treated for Kaposi sarcoma on a two-drug regimen (bleomycin and vincristine) with good clinical response. CONCLUSION: Visceral Kaposi sarcoma as a second malignancy may occur after pediatric acute lymphoblastic leukemia treatment, but its rarity makes it unlikely to raise suspicion among clinicians, thus precluding early diagnosis and treatment. We recommend routine evaluation for Kaposi sarcoma lesions in children undergoing long-term surveillance following treatment for childhood acute leukemia. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13256-022-03620-3.