Introduction

Longacre and Fenoglia-Preiser added the term ‘serrated adenoma’ to the medical lexicon just over two decades ago.1 When they re-evaluated so-called mixed hyperplastic adenomatous polyps, they noticed important histopathological differences with the common hyperplastic polyp, and coined the term ‘serrated adenoma’.1 Torlakovic and Snover further refined this observation in 1996 under the appellation, ‘serrated adenomatous polyposis’, in describing a hereditary or familial hyperplastic polyposis condition that predisposes to adenocarcinoma.2 As a result of this observation, a constellation of clinicopathological features emerged that define a new category of polyp, and in the last 6 or 7 years, the term ‘sessile serrated polyp or adenoma’ has appeared more frequently in the pathology and clinical literature. Despite this, there is still a degree of uncertainty surrounding the terminology, diagnostic criteria and importantly, the management implications. There is now no doubt that ‘sessile serrated polyp or adenoma’ is a premalignant lesion and, as such, it is incumbent on pathologists to be aware of and diagnose this lesion.

For the purposes of this brief overview, we intend to highlight the role of the pathologist in making the diagnosis and some of the confusing issues related to diagnosis, the state of play with regard to the molecular pathogenesis of these lesions and the clinical ramifications once a diagnosis of sessile serrated polyp/adenoma is made.