Abstract
Malignant peripheral nerve sheath tumor is a rare tumor occurring in 5%-10% of all malignant soft tissues sarcomas and triton tumor arising from neurofibromatosis type 1 (NF-1) is even rarer with associated high rate of mortality. No case of triton tumor has been reported in Nigeria to the best of our knowledge. We seek to report a case of lately detected retroperitoneal triton tumor presenting in a 12-year-old Nigerian child who was brought with bilateral lower limb weaknesses, weight loss, and a right lumbar mass. There were multiple café au lait spots on the body. Abdominal computerized tomographic scan revealed a huge right retroperitoneal mass crossing the midline, compressing adjacent structures with multilevel intraspinal extensions. Core needle biopsy performed and both histology and immunohistochemical studies confirmed the diagnosis, but patient demised in the course of care. The aim is to heighten suspicion of this extremely very rare malignant tumor in children with NF-1.