Colonic coinfection of histoplasma and cytomegalovirus mimicking carcinoma in a patient with HIV/AIDS

Histoplasma and Cytomegalovirus Coinfection of the Gastrointestinal Tract in a Patient with AIDS: A Case Report and Review of the Literature

Opportunistic infections of the gastrointestinal tract are well-documented complications of patients with acquired immunodeficiency syndrome (AIDS). However, concomitant infection by Histoplasma and cytomegalovirus has been described rarely. We present the case of an HIV patient with a CD4 count of 20 cells/uL who was admitted with odynophagia and weight loss. Endoscopic evaluation revealed ulcerations in the esophagus and colon, and a mass formation in cecum. Histology revealed budding yeasts in the cecum and a transverse colon consistent with Histoplasma. Urine Histoplasma antigen was positive. Esophageal tissue disclosed viral cytopathic changes. Immunostaining was positive for cytomegalovirus in the esophagus and transverse colon. The patient was started on appropriate antifungal and antiviral treatment with complete resolution of his symptoms. To our knowledge, this is the fifth case of Histoplasma and cytomegalovirus co-infection of the gastrointestinal tract in a patient with AIDS. We also review the literature for similar cases in regards to clinical presentation and the type of gastrointestinal involvement.

Gastrointestinal Histoplasmosis: A Case Series

Histoplasmosis is an invasive mycosis caused by inhalation of the spores of dimorphic fungi Histoplasma capsulatum. The disease manifests in the lung as acute or chronic pulmonary histoplasmosis and in severe cases gets disseminated in multiple organs like skin, adrenal gland, central nervous system, lymph node, liver, spleen, bone marrow, and gastrointestinal tract. It occurs most commonly in immunodeficient patients like HIV-positive patients and transplant recipients, while immunocompetent hosts are affected rarely. In cases of gastrointestinal histoplasmosis, the samples are collected for culture and biopsy should be sent for histopathological examination for definitive diagnosis. We conducted a retrospective study of colonic biopsies performed in the department of gastroenterology in a tertiary care hospital of north India from January 2014 to December 2015. Five cases of colonic histoplasmosis were diagnosed on histopathology out of which 4 patients were from north India while 1 patient was from Myanmar. The patients presented with various complaints, including loose stools, diarrhea, altered bowel habits, and gastrointestinal bleeding. The prognosis is very good after early and aggressive treatment while the disease is fatal if it remains untreated. In our study, 2 patients died within few days of diagnosis due to delay in the diagnosis, dissemination, and associated complications. Other patients were started on amphotericin B deoxycholate and are under follow-up. An early diagnosis of gastrointestinal histoplasmosis is important as appropriate treatment leads to long-term survival while untreated cases are almost fatal.

Dimorphic fungal coinfection as a cause of chronic diarrhea and pancolitis

Histoplasma capsulatum and Paracoccidioides brasiliensis are dimorphic fungi that cause systemic mycosis mostly in tropical South America and some areas of North America. Gastrointestinal involvement is not uncommon among these fungal diseases, but coinfection has not previously been reported. We report a patient with chronic diarrhea and pancolitis caused by paracoccidioidomycosis and histoplasmosis.

Cecal vanishing tumor associated with cytomegalovirus infection in an immunocompetent elderly adult

Gastrointestinal involvement in cytomegalovirus (CMV) infection is well documented among immunocompromised patients and is also observed in immunocompetent individuals. The presentation of this infection can sometimes mimic those of other diseases, thus making accurate diagnosis difficult. We herein report a rare case of an immunocompetent elderly adult with gastrointestinal CMV infection that presented as a vanishing tumor at the cecum. A 76-year old man initially presented with lower abdominal pain. Colonoscopy revealed a tumorous lesion with irregular ulceration observed at the ileocecal valve. Histological findings of a biopsy specimen revealed intranuclear inclusions which were positive for CMV on immunohistochemical staining. However, this tumorous lesion disappeared within 7 wk from the initial hospital visit without any further treatment. Inflammatory pseudotumors associated with CMV infection should be considered as a differential diagnosis of tumorous lesions in the colon, even in immunocompetent adults.

Pseudometastasis secondary to histoplasmosis infection: false-positive PET/CT findings

Positron emission computed tomography (PET)/CT is a common modality used in the workup of neoplastic conditions. However, false-positive results may be produced by underlying infectious processes. We report two cases of false-positive PET/CT studies secondary to histoplasmosis infections in both a pediatric and a young adult patient. After the diagnoses, one patient was observed with no therapy and the other received a complete course of itraconazole. In both cases biopsy results were positive for fungal elements consistent with histoplasmosis. Both patients were successfully managed and have had follow-up histoplasmosis titers that reveal resolving infections.

Human immunodeficiency virus-associated adenocarcinoma of the colon: clinicopathologic findings and outcome

BACKGROUND

Patients infected with Human immunodeficiency virus (HIV) living longer with antiretroviral therapy (ART) are more likely to develop non-AIDS-defining cancers such as adenocarcinoma of the colon. There have been limited case reports regarding HIV-associated colon adenocarcinoma. The aim of this study was to characterize the clinicopathologic findings and outcome in a series of HIV-infected patients diagnosed and treated for colon adenocarcinoma.

PATIENTS AND METHODS

A retrospective study involving HIV-related colon adenocarcinoma was performed. Cases were accrued from the personal archives and published case reports. Data regarding demographics, HIV acquisition, ART use, immunosuppression, cancer location, pathology, and outcome were extracted and analyzed.

RESULTS

A total of 17 patients were identified, including 7 personal cases. Patients were of average age 43 years (range, 25-67 years) and predominantly male (male:female ratio, 14:3). Most carcinomas (57%) involved the right colon, were largely TNM stage 4 cancers (47%), and, when present, metastases were mainly to the liver. Many (47%) individuals died within 1-26 months after their cancer diagnosis. Immunosuppression (AIDS diagnosis and/or CD4+ < 500 cells/mm3) did not appear to correlate with tumor grade, stage, or an adverse outcome.

CONCLUSION

These data show that HIV-infected patients with adenocarcinoma of the colon tend to be young men with a high incidence of right-sided involvement. Additional research is needed to determine if screening HIV-infected individuals for colon cancer should include younger patients and involve the entire colon.