Xiao, Shu‐Yuan

In keeping with the stated goal of providing the surgical pathologist with tools to recognize abnormalities of the gastrointestinal (GI) tract due to drugs (AGIDS), in part II of this review we embark in a more organ-based description of AGIDS. Adequate space is given to the numerous adverse gastrointestinal effects of nonsteroidal anti-inflammatory drugs. Pill esophagitis, esophagitis dissecans, proton pump inhibitors’ effects, diaphragm disease, and the recently described effects of drugs such as olmesartan, mycophenolate, and of compounds such as yttrium-90 are highlighted among several others. The inclusion of drug effects in the differential diagnosis of “conventional” diseases (such as gastric antral vascular ectasia, graft-versus-host disease, ischemic colitis, acute colitis, collagenous enteritis, inflammatory bowel disease) is underscored to avoid sometimes significant diagnostic pitfalls. We reiterate the message of the necessary collaboration between pathologist and clinician in the recognition of these entities to provide the best patient care.

Abnormalities of the gastrointestinal (GI) tract due to drugs (AGIDs) are numerous and have significant impact. The aim of this narrative review is to help the practicing surgical pathologist recognize selected AGIDs. The adverse drug effects presented were chosen with an emphasis on recent and significant pathological and clinical contributions. The selection was based on a thorough review of the PUBMED-based literature and on the authors’ opinions and experience. In the first part of the review, diagnostic abnormalities due to crystals (eg, iron, biphosphonates, nonsystemic drugs), mitosis arresting drugs (colchicine, taxanes), and biological agents, especially ipilimumab, are discussed. Some AGIDs’ histopathologic features can be easily recognized. It is however the clinical correlation that in many cases of AGIDs will provide the necessary support for a drug effect diagnosis. The identification of AGIDs requires heightened awareness of the medical team in which close collaboration of pathologists and clinicians cannot be overemphasized.