Even in well-described genetic syndromes, such as neurofibromatosis type 1, expansion of the phenotype should be considered as a possible explanation for atypical presentations. However, it is critical to complete the evaluation for a potential dual diagnosis, as there could be significant prognostic and management implications.
Keywords: PTEN hamartoma syndrome; colonic polyposis; dual diagnosis; hamartomatous polyps; hereditary polyposis syndrome; juvenile polyposis syndrome; neurofibromatosis type 1.