Recurrent Gastrointestinal Stromal Tumor With Chondroid Differentiation After Imatinib Therapy: An Unusual Case and Literature Review.

Gastrointestinal stromal tumor (GIST) is the most common mesenchymal tumor in the gastrointestinal tract and is most commonly seen in the stomach. The standard treatment for patients with advanced GISTs include both surgical resection and imatinib therapy. There have been cases that document the alterations of patients' GIST histomorphology both with primary GIST prior to imatinib therapy and with recurrent GIST after imatinib therapy. However, there has been no documented case of a patient who has recurrent GIST with chondroid differentiation at the primary site after imatinib therapy. In this article, we report an incidental finding of a 58-year-old patient who had two treatments of imatinib therapy prior to surgical resection of her recurrent GIST in her stomach. We also explore through a mini-literature review the various cases of GIST with chondroid differentiation that have been reported to compare the histomorphology, immunophenotype, and patient demographic of these cases. This article is significant for reporting a rare finding of GIST after imatinib therapy and highlights the various presentations that GIST could acquire after imatinib therapy that exclude another malignant process, such as chondrosarcoma.

An Unusual Discovery of Multi-Opportunistic Organisms in Gastrointestinal Biopsies of a Patient With Acquired Immunodeficiency Syndrome and Infectious Colitis.

Patients with acquired immunodeficiency syndrome (AIDS) have an increased risk of infectious colitis. While individual cases of infectious colitis are not rare, co-infections involving multiple opportunistic organisms are uncommon. Here, we present an AIDS patient with concurrent opportunistic gastrointestinal infections resulting in symptomatic infectious colitis. A 56-year-old woman with AIDS presented to the hospital with diarrhea, abdominal pain, and sepsis. Initial imagining revealed thickening of the colonic wall suggestive of colitis. The initial workup identified the presence of Campylobacter and Cryptosporidium through the GI Pathogen Multiplex Polymerase Chain Reaction Panel (bioMérieux BioFire®, Salt Lake City, USA), and stool parasite examination also confirmed the presence of Cryptosporidium. Despite treatment for these infections, the patient's diarrhea persisted. The patient had a sigmoidoscopy performed, and the biopsy results revealed the presence of Histoplasma capsulatum, cytomegalovirus (CMV), Herpes simplex virus (HSV), Cryptosporidium, and Campylobacter. The patient subsequently received appropriate treatment for each infection, leading to the resolution of both colitis and bacteremia. This case emphasizes the importance of considering multiple pathogens in the management of infectious colitis in patients with AIDS. The presence of one infectious agent does not preclude the presence of additional agents, and a thorough investigation can ensure a definitive diagnosis and optimal treatment for patients.