Microscopic Colitis: A Single Centre Experience Over An Eight Year Period, With Clinical Follow-Up.

Authors

Moore M1, Allen PB2, Loughrey MB1

Departments / Institutions

1Department of Histopathology, Royal Victoria Hospital, Belfast Health and Social Care Trust, Belfast, United Kingdom. 2Division of Gastroenterology, South Eastern Health and Social Care Trust, Belfast, United Kingdom.

Publication Date

Autumn 2017

Introduction

Microscopic colitis is an increasingly common chronic inflammatory disorder of the colon.

Aims

To assess cases diagnosed as lymphocytic colitis (LC) and collagenous colitis (CC) for patient demographics, endoscopic and histological features, associated autoimmune disorders, medication history, treatment and outcome.

Methods

The histopathology laboratory system within Belfast Trust was interrogated for cases of LC or CC between 2008-16. The study only included cases diagnosed by specialist gastrointestinal pathologists. Information was collected from electronic records on the parameters outlined above.

Results

141 patients with CC and 50 with LC were identified. Both diseases predominantly involved females in the seventh decade. 15% demonstrated mild endoscopic abnormalities and sampling protocols varied widely. 67(47%) of CC and 16(32%) of LC cases were diagnosed on a single set of random colonic biopsies. 43(30%) of CC and 16(32%) of LC cases had separate specimens taken from right and left colon. Histology was concordant in 40(93%) and 14(87%) of these cases respectively. In the remainder, the sampled left colon was normal. 18% of CC and 40% of LC cases had recognised associated autoimmune diseases. 80(57%) CC and 32(64%) LC patients were taking a recognised potentially causative drug at diagnosis. Of 191 cases, only one (of LC) was refractory to treatment. The rest exhibited clinical response to therapeutic drugs, causative drug withdrawal or no treatment.

Conclusion

Overall, CC and LC are benign conditions with similar demographics, associations, management and outcomes, with only subtle differences. Sampling of right colon at colonoscopy will avoid potentially missing 10% of cases.