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A5295 - An Unusual Presentation of Chronic Disseminated Histoplasmosis
Author Block: G. S. Thind, L. Yadav; Internal Medicine, WMU SCHOOL OF MEDICINE, Kalamazoo, MI, United States.
Introduction: Disseminated histoplasmosis is rare, and is generally seen in immunocompromised hosts. However, it has also been reported in middle-aged men without apparent immunosuppression. As our case illustrates, indolent multisystem involvement with seemingly unrelated symptoms may delay diagnosis.
Case: A 64-year-old male with a past history of diabetes, hypertension, and peripheral artery disease presented in the outpatient clinic with gradual onset of confusion, weakness, and 25-pound weight loss over three months. An MRI brain revealed two enhancing cerebellar lesions suspicious for metastases, and search for the primary tumor began. PET-CT showed enhancement of cervical and axillary lymph nodes. Over the next few days, patient’s mental status deteriorated, requiring admission to the ICU. While in the ICU, he underwent a left axillary lymph node biopsy that showed no evidence of malignancy. Rather, pathology revealed fungal organisms on the silver stain morphologically consistent with Histoplasma spp. Disseminated histoplasmosis with central nervous system involvement was suspected. HIV testing was negative.
Further history revealed that the patient had been having subjective chills for the past several months. He’s had mild pancytopenia for about two years, which had not been further evaluated. During this admission, his reticulocyte index showed suppressed marrow response. Additionally, he was worked up for occult gastrointestinal bleeding with an esophagogastroduodenoscopy three months ago, and was found to have a gastric ulcer. The biopsy had shown “granulomatous gastritis”; no further workup was done for this peculiar pathology. The patient also had an erythematous papular rash of unclear etiology in the lower extremities for one year.
Thereafter, several investigations were performed to confirm the diagnosis. Serological testing for Histoplasma capsulatum was positive in both serum and CSF. Bone marrow biopsy showed hypocellular marrow and scattered interstitial granulomas with fungal organisms most consistent with Histoplasma spp. Hence, the diagnosis was confirmed and patient was started on liposomal amphotericin B. Unfortunately, patient had a catastrophic stroke while inpatient and was transitioned to palliative comfort measures.
Discussion: This case exemplifies the multitude of manifestations of disseminated histoplasmosis and the diagnostic challenges therein. Persistent pancytopenia requires further workup, potentially including a bone marrow biopsy if there is evidence of a suppressed marrow response. Gastrointestinal lesions showing granulomatous inflammation should invoke an evaluation of potential granulomatous disorders including histoplasmosis. Unexplained skin lesions may warrant a skin biopsy. Awareness of these possible manifestations and their prompt workup can help make an earlier diagnosis, thereby leading to earlier treatment.