S2457 Histoplasma Hepatitis Presenting as Mirizzi Syndrome

Abstract

INTRODUCTION: Hepatitis secondary to Histoplasmosis is a pathology that is complex and difficult to diagnose. We report a case that presented as Mirizzi syndrome with respiratory dysfunction that proved to be disseminated histoplasmosis with hepatic involvement. CASE DESCRIPTION/METHODS: A 50 y/o female on adalimumab for rheumatoid arthritis presented with right-upper quadrant pain, a 5-day history of jaundice, fever and shortness of breath. Liver chemistries were elevated with alkaline phosphatase of 733 IU/L, total bilirubin of 7 mg/dl, AST 612 IU/L and ALT 202 IU/L. Abdominal ultrasonography revealed gallstones and mildly dilated common bile duct. A chest CT showed diffuse bilateral groundglass opacities. Based on the complex presentation and timing (mid March, 2020) the working diagnoses were gallstone disease with potential SARS-CoV2 infection. Endoscopic Retrograde Cholangiopancreatography exposed Mirizzi syndrome and a long-stent was placed into the bile duct. COVID-19 testing was negative. Liver enzymes showed minimal improvement and respiratory symptoms continued to worsen. Other laboratory tests as well as a detailed toxin intake (including alcohol) were negative. Due to the lack of improvement the patient underwent bronchoscopy and liver biopsy. The former showed buddying yeast in the lungs and the latter liver granulomas with PAS positive yeast consistent with Histoplasma. Liver biopsy cultures were positive for Histoplasma capsulatum. The patient was placed on Itraconazole and discharged home upon improvement. Eight weeks post discharge her liver enzymes have almost completely normalized and symptoms have resolved. DISCUSSION: Disseminated histoplasmosis affecting the liver is a relatively rare and often lethal complication of this infection. The confirmation of extra pulmonary disease is critical as the length of therapy extends from several weeks to one year. Histoplasma hepatitis has been reported in individuals undergoing immunosuppression, such as our patient, and a consistently reported characteristic has been a high AST to ALT ratio which can lead to an initial suspicion of alcoholic hepatitis. This should be kept in mind if the provided history is not compatible with toxin-related (alcohol) liver disease. Our patient also had a clinical presentation compatible with Mirizzi syndrome further obscuring the diagnosis. In this regard, alternative diagnoses should be thought if there are no dramatic improvements of liver chemistries following recanalization of the bile duct.