Conversatorio clínico patológico en el Hospital Nacional Arzobispo Loayza_2008-02. Translated title: Clinical Case at the Hospital Nacional Arzobispo Loayza- 2008-2

Histoplasmosis is a serious opportunistic infection in patients with AIDS, often representing the first manifestation of the syndrome. Most infections occurring within the endemic region are caused by exogenous exposure, while those occurring in nonendemic areas may represent endogenous reactivation of latent foci of infection or exogenous exposure to microfoci located within those nonendemic regions. However, prospective investigations are needed to prove the mode of acquisition. The infection usually begins in the lungs even though the chest roentgenogram may be normal. Clinical findings are nonspecific; most patients present with symptoms of fever and weight loss of at least 1 month's duration. When untreated, many cases eventually develop severe clinical manifestations resembling septicemia. Chest roentgenograms, when abnormal, show interstitial or reticulonodular infiltrates. Many cases have been initially misdiagnosed as disseminated mycobacterial infection or Pneumocystis carinii pneumonia. Patients are often concurrently infected with other opportunistic pathogens, supporting the need for a careful search for co-infections. Useful diagnostic tests include serologic tests for anti-H. capsulatum antibodies and HPA, silver stains of tissue sections or body fluids, and cultures using fungal media from blood, bone marrow, bronchoalveolar lavage fluid, and other tissues or body fluids suspected to be infected on clinical grounds. Treatment with amphotericin B is highly effective, reversing the clinical manifestations of infection in at least 80% of cases. However, nearly all patients relapse within 1 year after completing courses of amphotericin B of 35 mg/kg or more, supporting the use of maintenance treatment to prevent recurrence. Relapse rates are lower (9 to 19%) in patients receiving maintenance therapy with amphotericin B given at doses of about 50 mg weekly or biweekly than with ketoconazole (50-60%), but controlled trials comparing different maintenance regimens have not been conducted. Until results of such trials become available, our current approach is to administer an induction phase of 15 mg/kg of amphotericin B given over 4 to 6 weeks, followed by maintenance therapy with 50 to 100 mg of amphotericin B given once or twice weekly, or biweekly. If results of a prospective National Institutes of Allergy and Infectious Disease study of itraconazole maintenance therapy document its effectiveness, alternatives to amphotericin B may be reasonable.

The scarcity of reported cases of paracoccidioidomycosis and AIDS remains unexplained. We review the details of the 27 cases reported in the medical literature. Paracoccidioidomycosis occurs in patients with advanced AIDS who are not receiving prophylaxis for Pneumocystis carinii pneumonia with trimethoprim-sulfamethoxazole, which is also effective against Paracoccidioides brasiliensis. Clinical manifestations include prolonged fever, weight loss, generalized lymphadenopathy, splenomegaly, hepatomegaly, and skin rash. Diagnosis can often be made by direct microscopic examination and culture of the fungus from skin and lymph node specimens and occasionally from sputum, blood, spinal fluid, and bone marrow specimens. Since antibodies to P. brasiliensis are occasionally detected, the diagnosis should not be ruled out for patients whose serology is negative. Despite specific therapy with different regimens, the overall mortality of paracoccidioidomycosis among patients with AIDS is high (30%). The prognosis can be improved by earlier diagnosis and aggressive therapy with amphotericin B, followed by lifelong immunosuppressive therapy with trimethoprim-sulfamethoxazole. Health care providers caring for human immunodeficiency virus-infected patients who live or have resided in areas in which paracoccidioidomycosis is endemic must be aware of the possibility that this systemic mycosis may occur and have potentially severe consequences.

To assess the causes of ileocecal mass in patients with amebic liver abscess. Patients with amebic liver abscess and ileocecal mass were carefully examined and investigated by contrast-enhanced CT scan followed by colonoscopy and histological examination of biopsy materials from lesions during colonoscopy. Ileocecal masses were found in seventeen patients with amebic liver abscess. The cause of the mass was ameboma in 14 patients, cecal tuberculosis in 2 patients and adenocarcinoma of the cecum in 1 patient. Colonic ulcers were noted in five of the six (83%) patients with active diarrhea at presentation. The ileocecal mass in all these patients was ameboma. Ulcers were seen in only one of the 11 (9%) patients without diarrhea. The difference was statistically significant from the group with diarrhea (P< 0.005). Ileocecal mass is not an uncommon finding in patients with amebic liver abscess. Although, the ileocecal mass is due to ameboma formation in most cases, it should not be assumed that this is the case in all patients. Colonoscopy and histological examination of the target biopsies are mandatory to avoid missing a more sinister lesion.