GASTROENTEROLOGY ARTICLE OF THE WEEK
March 10, 2005
Kahi CJ, Wheat LJ, Allen SD, Sarosi GA. Gastrointestinal Histoplasmosis. Am J Gastroenterol 2005;100:220-231.
[GIH = gastrointestinal histoplasmosis]
1. Esophageal involvement in histoplasmosis
a. dysphagia from mediastinal fibrosis
b. diverticulum, ulceration or erosions from mediastinal adenitis
c. stenosis of the distal esophagus
d. multiple esophageal nodules in progressive disseminated histoplasmosis
2. Typical histologic findings in GIH include
a. acute neutrophilic inflammatory infiltrate
b. granuloma formation
c. diffuse lymphohystiocytic infiltrates
d. fungi often present within the cytoplasm of macrophages
e. in immunocompromised individuals the diagnosis can be made on histologic exam of samples obtained from endoscopically-normal mucosa
f. special stains are needed in most cases to see the organism on light microscopy
3. Therapy for mediastinal histoplasmosis
a. some may heal spontaneously
b. itraconazole for 6-12 months is the therapy of choice for most patients
c. therapy is most likely to be helpful in those with fibrosing mediastinitis
d. amphotericin B is recommended for disseminated histoplasmosis
True or False
4. GIH does not affect immunocompetent hosts
5. There is a male predominance in GIH, presenting age is usually early 20’s
6. Intestinal involvement in disseminated histoplasmosis most often affects the ileum.
7. Calcified granulomata after self-limited infection are usually found in the lung, liver and spleen.
8. Esophageal involvement in histoplasmosis can occur as direct extension from mediastinal nodes which are often involved in the disease process.
9. Large friable colonic mass mimicking a carcinoma may be the presenting sign of histoplasmosis in an immunocompromised individual
10. Urine test for histoplasma antigen is most useful in cases of disseminated histoplasmosism, it can be used to monitor response to therapy