We appreciate the interest Dr. Montes-Arcón showed in our case report, “Tuberculosis and Crohn’s disease – a challenging endoscopic diagnosis”1. The primary aim of presenting our case was to provide evidence of and review the clinical and endoscopic characteristics of the two entities. Even though they have similarities, several of their differences should be underlined to help distinguish one from the other, both clinically and during the endoscopic procedure, to aid clinical gastroenterology specialists in making the accurate diagnosis, while in no way devaluing the role of other physicians that make up the multidisciplinary team managing the two diseases.

The role of the pathologist in the approach to the two entities is undeniable and we share the belief that the definitive diagnosis depends on the analysis of the pathologic anatomy. We recognize the challenge involved in that analysis, given that the two diseases share a considerable number of histologic characteristics that include architectural anomalies (crypt distortion, non-parallel crypts, variable diameters or cystically dilated crypts, crypt branching that involves more than 2 branched crypts, crypt shortening, reduced crypt density, and irregular mucosal surfaces) and inflammatory features (focal/patchy inflammation, basal plasmacytosis, increase in intraepithelial lymphocytes, transmucosal inflammation, focal cryptitis, aphthous ulcers, disproportionate submucosal inflammation, proximal location of the ulceration and architectural distortion, pseudopyloric metaplasia in the ileum, Paneth cell metaplasia in the colon, and granulomas)2,3.

However, despite the difficulties, there are some histologic criteria that enable an adequate distinction to be made, based on the granulomas found. In intestinal tuberculosis, granulomas tend to be larger, have a central formation of caseous tissue, are located in the submucosa, have granulomatous non-mucosal involvement of the surrounding lymph nodes, disproportionate inflammation of the submucosa, and linear ulceration with clusters of epithelioid histiocytes. With respect to Crohn’s disease, the findings included architectural distortion at a distance from the granulomatous inflammation, focally improved colitis, and muscular obliteration of the mucosa3,4.

Clinical, endoscopic, and imaging differentiation is of great use to the pathologist, when despite his/her analysis, the entities cannot be distinguished, or a definitive diagnosis made. Thus, said differentiation aids in guiding the diagnosis. Other techniques, such as Mycobacterium species cultures, polymerase chain reaction testing for mycobacteria, and histochemical staining for acid-alcohol-fast bacilli (Ziehl-Neelsen) can also be useful3,5.

We agree that the approach to the patient suspected of presenting with intestinal tuberculosis versus Crohn’s disease is a multidisciplinary one, and the majority of times involves gastroenterologists, general surgeons, imaging specialists, anatomopathologists, and others.