A Diagnostic Dilemma: Disseminated Histoplasmosis Presenting as a Small-Bowel Obstruction

BACKGROUND Histoplasma is a common fungus that lives in the environment, and in the form of disseminated histoplasmosis (DH) it can often present with a long range of unspecific symptoms, mimicking other diseases. For these reasons, missed or delayed diagnoses of DH are common, and often fatal. Limitations in the diagnostic testing techniques used for suspected histoplasmosis further aggravate the difficulties that arise with cases of this infection. Previous cases of misdiagnosis or delayed diagnosis leading to bowel obstruction have been reported. CASE REPORT A 64-year-old woman with a history of rheumatoid arthritis on TNF-alpha inhibitor presenting with abdominal pain, bloating, and severe weight loss was found to have a stricture in the ileum with ulceration and inflammation, raising suspicion for Crohn's disease. Additionally, symptomatic hypercalcemia, dyspnea, and findings suggestive of primary sclerosing cholangitis (PSC) developed later. Intestinal obstruction due to an ileal stricture ultimately resulted in the patient undergoing an ileocolic resection with creation of a primary ileocolic anastomosis and diverting loop ileostomy. Repeated false-negative Histoplasma urine antigen and PCR testing further complicated the case, delaying the diagnosis and treatment of the histoplasmosis infection. CONCLUSIONS This report highlights the immense difficulties involved in the diagnosis of abnormal cases of histoplasmosis and stresses the importance of maintaining a high index of suspicion for this opportunistic infection in immunocompromised patients, especially those residing in, or with recent travel to, areas of high endemicity to avoid misdiagnosis or delays in diagnosis leading to complications.