Magali Svrcek © ECCO

Immune checkpoints (ICK) are downregulators of T cell immunity. Immune checkpoint inhibitors (ICKi), by blocking the co-inhibitory receptors on T cells to activate their cytotoxic immune function, have become a major therapeutic tool in oncology, notably for the treatment of metastatic melanoma, non-small cell lung carcinoma, renal cell carcinoma, urothelial carcinoma and mismatch repair (MMR) deficient/microsatellite-unstable tumours. In particular, therapeutic monoclonal antibodies have emerged against cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4), which primarily inhibits T cell activation, and programmed cell death 1 (PD-1), which limits the effector function of activated T cells in the periphery. Food and Drug Administration-approved ICKi include ipilimumab (CTLA-4 inhibitor), pembrolizumab and nivolumab (anti-PD-1) and atezolizumab (anti-PD-L1).

Gert de Hertogh © ECCO

Histopathologists have traditionally fulfilled three functions in Inflammatory Bowel Disease (IBD) care. First, they play a role in the initial diagnosis, together with gastroenterologists, endoscopists and radiologists. Second, they establish a differential diagnosis at clinical flares of the disease, resolving the question of whether there is reactivation of the IBD, a superinfection or an unrelated pathology. Third, they are involved in the screening of patients for premalignant lesions and cancer.

Paula Borralho Nunes © ECCO

A significant number of patients with Ulcerative Colitis (UC) will require a colectomy [1], with the most frequent indications including medical refractory disease and the occurrence of dysplasia or cancer in cases of longstanding disease. A total proctocolectomy with ileal pouch–anal anastomosis (IPAA) has become the surgery of choice for the “definitive” management of UC since it avoids a permanent stoma while removing all diseased colonic mucosa [2], but it is also used for familial adenomatous polyposis and sometimes (advertently or inadvertently) for Crohn’s Disease (CD). However, although this surgery has significantly improved the quality of life of patients with UC, complications such as fistulas, abscesses, strictures of the anastomosis and pouchitis can occur after restorative proctocolectomies. Pouchitis refers to a chronic relapsing inflammatory condition with active inflammation of IPAA mucosa and is considered to be a primary “non-specific, idiopathic inflammation of the neorectal ileal mucosa”. 

Magali Svrcek © ECCO

In addition to the “classical” pathway of colorectal carcinogenesis, involving development of cancer from an adenomatous precursor lesion, an alternative pathway, the serrated pathway, is now recognised to exist, and it is estimated that approximately 30% of colorectal cancers (CRC) arise via this alternative pathway [1]. In the last WHO classification, serrated polyps were classified as (i) hyperplastic polyps (HP), (ii) sessile serrated adenoma/polyps (SSA/P), with or without dysplasia, and (iii) traditional serrated adenomas (TSA). The possibility of a serrated pathway has also been suggested in colorectal carcinoma complicating Inflammatory Bowel Disease (IBD) [2–4]. Little is known concerning immunohistochemical and molecular features of serrated lesions in IBD: Data are limited to small series of patients or case reports and findings are controversial due to the rarity of the cases. However, the clinical, pathological and biological characteristics of serrated polyps in patients with IBD do seem to resemble those of their sporadic counterparts.

Roger Feakins © ECCO

The 3^rd Histopathologists of ECCO (H-ECCO) Masterclass took place in Vienna on February 15–16, 2018.

Since its formation in 2016, the Histology Working Group of ECCO (H-ECCO) has organised a successful annual educational Masterclass. The 3rd H-ECCO Masterclass at the 2018 ECCO Congress in Vienna ran on Thursday afternoon and Friday morning. It coincided with an important event: The official conversion of the H-ECCO Working Group to a full committee on the Thursday evening.  Attendance at the Masterclass was good (over 70 registrants) and the audience comprised a mixture of histopathologists and gastroenterologists from Europe and further afield.

Vincenzo Villanacci  ©  ECCO

The Inflammatory Bowel Diseases (IBD) Crohn’s Disease (CD) and Ulcerative Colitis (UC) are characterised by flares and remission, reflecting the pathological status of the inflamed intestinal tract. For decades, the treatment goal for IBD was the achievement of clinical response or remission. More recently, however, the normalisation of laboratory parameters and intestinal mucosa, termed mucosal healing (MH), has been considered a major target to prevent extra-intestinal complications and achieve sustained clinical remission.