Abstract
BACKGROUND: Neurofibromatosis type 1 (NF1) and Peutz-Jeghers syndrome (PJS) are distinct autosomal dominant disorders. Their concomitant occurrence is exceptionally rare. This report describes a unique pediatric case of this dual diagnosis. CASE PRESENTATION: An 8-year-old boy presented with paroxysmal abdominal pain accompanied by crying. He had multiple café-au-lait macules and a family history of NF1. He experienced recurrent intussusception resistant to non-invasive reduction. Exploratory laparotomy revealed jejunal intussusception caused by hamartomatous polyps, leading to resection and anastomosis. Histopathology revealed hamartomatous polyps consistent with PJS. Subsequent genetic testing revealed a paternally inherited pathogenic NF1 variant and a de novo pathogenic STK11 variant, confirming the dual diagnosis. Comprehensive evaluation identified additional NF1-associated features, including intracranial lesions. The patient recovered well postoperatively and remained asymptomatic during one-year of follow-up. CONCLUSIONS: This case highlights one of the rare documented instances of concurrent NF1 and PJS. It underscores the critical importance of considering a second underlying pathology in patients with known genetic disorders who present with atypical or refractory symptoms. The diagnosis was ultimately corroborated by comprehensive genetic testing, underscoring its pivotal role in delineating complex phenotypes. A high index of suspicion is necessary for timely diagnosis. Optimal management for such complex cases requires a multifaceted approach, including appropriate surgical intervention and establishing a long-term, multidisciplinary surveillance strategy to address the cumulative cancer risks and multi-system complications associated with both syndromes. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12887-026-06662-4.