Diagnosis and Discussion

Diagnosis

Lymphocytic colitis with multinucleated giant cells.

Discussion

Microscopic colitis (MC) is an entity clinically characterized by patients with chronic watery diarrhea and normal or near-normal findings on colonoscopy. MC most often refers to its two main histologic variants: lymphocytic colitis (LC) and collagenous colitis (CC). The etiology of MC remains unknown, with selected literature proposing that LC and CC are within the same spectrum of disease. Of note, autoimmune diseases, drugs, and infectious processes have been associated with MC. Patients with MC, regardless of histologic subtype, are treated with steroids and there is usually spontaneous resolution of disease within weeks to months.

The diagnosis of MC is rendered following histopathologic analysis. LC and CC demonstrate similar morphologic findings, such as normal colonic crypt architecture, an expanded lamina propria, and surface epithelial damage. In LC, there is increased chronic inflammation, particularly lymphocytes, throughout the surface and crypt epithelium. In contrast, CC has an expanded collagen band beneath the surface epithelium, which may extend into the lamina propria and surround capillaries.

First described by Libbrecht at al. in 2002, MC with giant cells has been considered another histologic variant of MC. Patients present with the typical clinicopathologic features of MC, including watery diarrhea and LC or CC; however, there are also subepithelial multinucleated giant cells throughout the lamina propria. Much like LC and CC subtypes, the etiology of MC with giant cells is unclear. One hypothesis suggests that these giant cells arise from macrophages that aggregate in response to a trigger within the colonic lumen. Another hypothesis advocates that giant cell formation is caused by a response to the subepithelial collagen band, particularly in CC, and the giant cells are seen as a part of LC after they have thinned the collagen layer. Other authors report that the giant cells remain following resolution of MC, proposing that a more pure form of giant cell colitis results from the progression of MC. Ultimately, the literature concludes that there is no clinical significance of MC with giant cells. 

Although MC with giant cells currently has no clinical significance, it is important to recognize this subtype so as to distinguish it from other more serious processes. These include sarcoidosis, tuberculosis, Wegener’s granulomatosis, and Crohn’s disease. As Crohn’s carries a more serious lifelong diagnosis, it is important to look for architectural distortion, basal lymphoplasmacytosis, and basally located giant cells, which distinguish it from MC with giant cells.

References

Brown IS, Lambie DL. Microscopic colitis with giant cells: a clinico-pathological review of 11 cases and comparison with microscopic colitis without giant cells. Pathology. 2008;40(7):671-675.

De Petris G, Chen L. Evolution of microscopic colitis to giant cell colitis without significant intraepithelial lymphocytosis or thickened collagen plate. Int J Surg Pathol. 2015;23(3):225-229.

Freeman HJ, Nimmo M. Carpet-like polypoid lesion in collagenous colitis with mucosal giant cells. Can J Gastroenterol. 2011;25(4):187-188.

Libbrecht L, Croes R, Ectors N, Staels F, Geboes K. Microscopic colitis with giant cells. Histopathology. 2002;40(4):335-338.

Pardi DS. Diagnosis and Management of Microscopic Colitis. Am J Gastroenterol. 2017;112(1):78-85.

Rotimi O, Rodrigues MG, Lim C. Microscopic colitis with giant cells-is it really a distinct pathological entity? Histopathology. 2004;44(5):503-505.

Sandmeier D, Bouzourene H. Microscopic colitis with giant cells: a rare new histopathologic subtype? Int J Surg Pathol. 2004;12(1):45-48.
 

Go Back