Next-generation sequencing in the genomic profiling of synchronous colonic carcinomas: comment on Li et al (2015)

Colorectal cancer (CRC) occurs as multiple, either synchronous or metachronous, neoplasms in 2–5% of the patients.1 Their onset may reflect either independent primaries or a metastatic spread from an original single neoplastic site. A careful pathological workup in order to clarify the origin of multiple colonic tumours is crucial to guide treatment. However, in some instances this distinction is challenging, requiring an accurate characterisation of the individual tumours, as exemplified by the case reported by Li et al.