Gastrointestinal histoplasmosis may be a rare initial manifestation in immunocompromised
patients. We present a case of colonic histoplasmosis in a patient with human immunodeficiency
virus (HIV), disseminated disease, and an unusual presentation.
A 56-year-old woman with no past medical history of note presented with progressive
cognitive decline and an unintentional 95-pound weight loss over the previous year.
The patient had been interacting less and was unable to walk because of a severely
impaired gait. On physical examination, she was alert but disoriented with poor memory.
She reported no gastrointestinal symptoms.
Her laboratory data were notable because they showed pancytopenia, but an initial
neurologic and infectious work-up was negative. A magnetic resonance imaging (MRI)
scan of her brain showed no acute intracranial pathology. Blood, urine, cerebrospinal
fluid (CSF), and sputum culture results were negative. A computed tomography (CT)
scan showed diffuse bilateral ground-glass opacities in the lungs, splenomegaly, and
thickening of the wall of the ascending colon. A bronchoscopy was performed, and bronchial
washings and biopsies were negative for fungal organisms.
The patient underwent a colonoscopy, which demonstrated a large 10-cm ulcerated area
of mucosa with heaped-up edges in the ascending colon, suspicious for malignancy ([Fig. 1]). Biopsies from this area showed prominent granulomatous reaction, but no dysplasia
or malignancy was identified. Periodic acid–Schiff reaction (PAS), a fungal stain,
revealed numerous intracytoplasmic and extracellular fungal organisms consistent with
Histoplasma capsulatum ([Fig. 2]).
Fig. 1 Endoscopic appearances in a 56-year-old woman who presented with progressive cognitive
decline and unintentional weight loss and was subsequently diagnosed as having acquired
immune deficiency syndrome (AIDS) showing: a a large ulcerated area in the ascending colon; b the heaped-up margins of the ulcerated area.
Fig. 2 Histologic appearance of a biopsy taken from the ulcerated area stained using the
periodic acid–Schiff reaction (PAS) showing granulomatous inflammation with intracellular
fungal organisms (arrowheads), consistent with Histoplasma capsulatum (magnification × 600).
The patient was positive for HIV by enzyme-linked immunoassay (ELISA) and Western
blot, with a CD4 count of 29, and was diagnosed with acquired immune deficiency syndrome
(AIDS). She was treated initially with amphotericin B for disseminated histoplasmosis,
which produced a clinical improvement, and was then changed to itraconazole as consolidation
therapy.
Histoplasmosis is a common opportunistic infection in immunocompromised patients with
HIV and has been an AIDS-defining illness. The causative organism H. capsulatum is the most common fungus in the USA and is endemic in the Mississippi and Ohio River
Valleys. Disseminated histoplasmosis occurs from hematogenous spread of the inhaled
fungal spores or reactivation of histoplasma granulomas. Gastrointestinal involvement
in disseminated histoplasmosis is common (70 % – 90 % in autopsy studies); however,
it is rarely identified during life [1]. The ileocecal area is commonly affected, presumably because of the abundant lymphoid
tissue in this region. In our patient, diagnostic work-up did not reveal extracolonic
histoplasmosis.
Gastrointestinal symptoms in disseminated histoplasmosis are nonspecific and may include
abdominal pain, diarrhea, fever, weight loss, bleeding, and obstruction [2]. Endoscopic findings may include erythema, ulceration, stricture, or mass lesion,
and may be misdiagnosed as colitis or malignancy [3]. Definitive diagnosis can be obtained by endoscopic biopsy of a lesion that subsequently
demonstrates intracytoplasmic organisms. Disseminated histoplasmosis should be included
in the differential diagnosis in immunocompromised patients with abnormal gastrointestinal
imaging or symptoms. It is usually fatal if not diagnosed early and treated rapidly.
Endoscopy_UCTN_Code_CCL_1AD_2AZ
