Colonic involvement in disseminated histoplasmosis of an immunocompetent adult: case report and literature review

Abstract

BackgroundHistoplasmosis is a common opportunistic fungal infection that is observed almost exclusively in immunodeficient patients, especially those with AIDS. Immunocompetent individuals that suffer from histoplasmosis are rarely reported, especially those with disseminated lesions, such as disseminated histoplasmosis. The observation of disseminated histoplasmosis with prominent gastrointestinal involvement, no respiratory symptoms (which is presumed to be the portal of infection), gastrointestinal pathological changes, and minor digestive system disorders make this case study exceedingly rare.Case presentationWe report the case of a 33-year-old immunocompetent male who presented with fever and weight loss. Based on investigations, the patient showed pancytopenia, hepatosplenomegaly, bone marrow involvement and marked colonic involvement. Finally, disseminated histoplasmosis was diagnosed and confirmed by stained smears of fine needle aspirates and biopsy from lesions in the bone marrow and colon. The patient showed appreciable regression of lesions following prompt treatment with amphotericin B deoxycholate, and was treated thereafter with oral itraconazole following discharge from hospital.ConclusionDisseminated histoplasmosis could be underestimated in immunocompetent patients. A high degree of clinical suspicion is essential in both immunocompromised and immunocompetent patients, regardless of pulmonary symptoms, and whether in endemic or non-endemic areas. Early and accurate diagnosis is extremely important for the appropriate treatment of infection and to improve disease outcome.

Atypical Obstructive Pseudotumors in AIDS as the Initial Manifestation of Gastrointestinal Histoplasmosis

“…Histoplasmosis is a common comorbidity in AIDS patients [8]; however, this condition can also be reported in immunocompetent patients [4,9].…”

“…The infection is caused by breathing spores from soil contaminated by bird and bat droppings [1,4,9]. For this reason, pulmonary histoplasmosis is the classical presentation of the infection.…”

Histoplasmosis aguda diseminada en un niño inmunocompetente

“…Por vía linfática, alcanza el ganglio satélite formando el complejo pulmonar bipolar, semejante al complejo de Ghon de la tuberculosis, uno de los diagnósticos diferenciales principales que tuvimos en cuenta. Luego a ésta, puede presentarse diseminación hematógena comprometiendo cualquier sistema u órgano, como se halló en nuestro paciente (compromiso en médula ósea y sospecha en el sistema nervioso central) 18 . La forma clínica primaria generalmente es autolimitada en personas inmunocompetentes pero puede progresar con una evolución y severidad variable en los inmunosuprimidos 3,15,19 .…”

Disseminated histoplasmosis diagnosed on routine outpatient endoscopy in a renal transplant patient

“…When present, nonspecific symptoms of GIH include fever, weight loss, abdominal pain, diarrhea, nausea, anorexia, vomiting, and constipation. [4,5] Gastrointestinal involvement in disseminated histoplasmosis is recognized in less than 10% of patients. At autopsy, however, it is seen in 70% of those with disseminated histoplasmosis, suggesting GIH has a higher prevalence than is clinically recognized.…”

“…[2,3] Disseminated histoplasmosis most commonly affects the gastrointestinal tract, but may also disseminate to other organs to include the skin, adrenal gland, central nervous system, lymph nodes, liver, spleen, and bone marrow. [4] GIH is generally asymptomatic and is rarely diagnosed on routine outpatient endoscopy. When present, nonspecific symptoms of GIH include fever, weight loss, abdominal pain, diarrhea, nausea, anorexia, vomiting, and constipation.…”