D0089 - A Wolf in Sheep's Clothing: Isolated Colonic Histoplasmosis as a Rare and Devastating Disease in Patients Undergoing Immunomodulator Therapy - A Systematic Review
St. Francis Hospital and Medical Center Hartford, CT
Faisal Inayat, MBBS1, Gul Nawaz, MD2, Muhammad Adnan Zaman, MD3, Arslan Afzal, MD4, Zaka Ul Haq, MD5, Rizwan Ishtiaq, MD6 1Allama Iqbal Medical College, Lahore, Punjab, Pakistan; 2Marshfield Medical Center, Marshfield, WI; 3Conemaugh Memorial Medical Center, Johnstown, PA; 4Woodhull Medical Center, Brooklyn, NY; 5Hackensack Meridian Raritan Bay Medical Center, Perth Amboy, NJ; 6St. Francis Hospital and Medical Center, Hartford, CT
Introduction: Gastrointestinal histoplasmosis is mainly considered a protean manifestation of disseminated histoplasmosis. It can mimic inflammatory bowel disease (IBD), cancer, or other bowel diseases, presenting diagnostic and therapeutic challenges. To our knowledge, this report represents the first systematic review on isolated colonic histoplasmosis in patients receiving immunomodulator therapy (IMT).
Methods: A systematic search of MEDLINE, Google Scholar, Embase, and Scopus was conducted for English-only studies, published between inception and June 15, 2022. Abstracts from major GI conferences and articles’ reference lists were also screened. The search terms “Histoplasma capsulatum,” and ‘‘histoplasmosis’’, were combined using the Boolean operators ‘AND’ and ‘OR’ with the terms “isolated colonic” and ‘’colon’’, with all permutations. Two authors reviewed each study to determine eligibility. The search yielded a total of 264 relevant results. However, only 13 articles fulfilled the inclusion criteria.
Results: A total of 13 patients were identified with isolated colonic histoplasmosis in the setting of IMT. The mean age was 55.62 ± 10.66 years, and 62% of patients were women. Screening colonoscopy incidentally diagnosed histoplasmosis in 38% of patients. Common symptoms were diarrhea 31%, weight loss 23%, or abdominal pain 23%. IMT was mainly administered for liver transplant 31%, renal transplant 31%, and ulcerative colitis 15%. Colonoscopy mostly revealed colonic ulcers 69%, polypoid lesions 15%, or hemorrhage 15%. Of 38%, Histoplasma antigen was positive in 23% of patients. Colonic biopsy diagnosed 85% of patients. Unfortunately, 15% of patients also underwent GI surgery for diagnosis. Amphotericin B with itraconazole 54%, itraconazole alone 38%, and amphotericin B alone was administered in 8% of patients. All patients achieved complete recovery.
Discussion: This systematic review shows that isolated colonic involvement can be the only clinical presentation of disseminated or primary histoplasmosis. Gastroenterologists should consider it in patients undergoing IMT who present with consistent symptoms. GI histoplasmosis should be ruled out before starting immunosuppressive therapy for colitis due to other causes. Colonoscopy with biopsy can play a pivotal diagnostic role in suspected patients (Figure 1). Prompt detection and antifungal treatment can result in uneventful recovery. However, delayed identification and improper treatment can lead to death in immunocompromised individuals.
Figure: Figure 1. A 65-year-old Caucasian female who was receiving methotrexate for rheumatoid arthritis presented with watery diarrhea for 15 days. Colonoscopy was only remarkable for one sessile polyp in the descending colon (Panel A). Pathology of the polypectomy specimen revealed multiple tiny yeast-like organisms on GMS stain (Panel B). PAS staining confirmed Histoplasma capsulatum (Panels C and D). The patient was finally diagnosed with primary isolated colonic histoplasmosis and she recovered well with antifungal treatment.
Disclosures:
Faisal Inayat indicated no relevant financial relationships.
Gul Nawaz indicated no relevant financial relationships.
Muhammad Adnan Zaman indicated no relevant financial relationships.
Arslan Afzal indicated no relevant financial relationships.
Zaka Ul Haq indicated no relevant financial relationships.
Rizwan Ishtiaq indicated no relevant financial relationships.
Faisal Inayat, MBBS1, Gul Nawaz, MD2, Muhammad Adnan Zaman, MD3, Arslan Afzal, MD4, Zaka Ul Haq, MD5, Rizwan Ishtiaq, MD6. D0089 - A Wolf in Sheep's Clothing: Isolated Colonic Histoplasmosis as a Rare and Devastating Disease in Patients Undergoing Immunomodulator Therapy - A Systematic Review, ACG 2022 Annual Scientific Meeting Abstracts. Charlotte, NC: American College of Gastroenterology.
