Granulomatous Hepatitis as Primary Manifestation of Disseminated Histoplasmosis in an Immunocompetent Host Diagnosed on EUS FNA and Liver Biopsy

ABSTRACT

Introduction: Disseminated histoplasmosis (DH) presents as primarily lung manifestations with extrapulmonary involvement in immunocompromised hosts. Granulomatous hepatitis as first presentation of DH in an immunocompetent host is uncommon. Case Description/Methods: 25-year-old female presented with one month of fever, fatigue, myalgias, 30-pound weight loss, cough, nausea, vomiting, and epigastric pain. She has lived in the Midwest and southwestern US. Presenting labs TB 1.9 mg/dL, AP 161 U/L, AST 172 U/L, ALT 463 U/L. Workup was negative for COVID, viral/autoimmune hepatitis, sarcoidosis, tuberculosis, and HIV. CT scan showed suspected gallstones and 9 mm left lower lobe noncalcified nodule. EUS showed a normal common bile duct, gallbladder sludge and enlarged porta hepatis lymph nodes which underwent fine needle aspiration (FNA). She was diagnosed with biliary colic and underwent cholecystectomy, with white plaques noted on the liver surface (A). Liver biopsy/FNA showed necrotizing granulomas (B) and fungal yeast on GMS stain (C). Although histoplasmosis urine and blood antigens were negative, histoplasmosis complement fixation was >1256. She could not tolerate itraconazole for DH, requiring amphotericin B. She then transitioned to voriconazole, discontinued after 5 weeks due to increasing AP. However, her symptoms resolved with normal transaminases. At one year follow up, she is asymptomatic with normal liver function tests. Discussion(s) DH is a systemic granulomatous disease caused by Histoplasma capsulatum endemic to Ohio, Mississippi River Valley, and southeastern US. DH more commonly affects immunocompromised hosts with AIDS, immunosuppressants, and organ transplant. Gastrointestinal involvement is common in DH (70-90%) with liver involvement in 90%. However, granulomatous hepatitis as primary manifestation of DH is rare (4% of liver biopsies). Hepatic granulomas are seen in < 20%. Patients may present with nonspecific systemic symptoms. Serum/urine antigens may be negative. Gold standard for diagnosis is identifying yeast on tissue stains. Recommended treatment is amphotericin B followed by 1 year of itraconazole. However, shorter treatment duration may be effective in immunocompetent hosts. This case is unique in that granulomatous hepatitis was the first presentation of DH in our immunocompetent patient diagnosed on EUS FNA and liver biopsy. Clinicians must have a high degree of suspicion for DH in patients with fever of unknown origin especially in endemic areas regardless of immunologic status. (Table Presented).