Rare Hepatic Cryptococcosis Mimicked Metastatic Liver Cancer and Confirmed by Metagenomic Next-Generation Sequencing in an Immunocompetent Patient: A Case Report

Abstract

Background Cryptococcus neoformans ( C. neoformans) is commonly presented in immunocompromised individuals and causes cryptococcosis mostly in the respiratory and/or central nervous system. Liver cryptococcosis is exceedingly rare and sometimes difficult to diagnose through conventional assays. Case Presentation The present study reports a rare case of liver cryptococcosis characterized by increased serum carbohydrate antigen 19–9 (CA19-9) level and intrahepatic multiple nodules without other symptoms in an immunocompetent woman. Her cancer family history and imaging examinations initially suspected metastatic liver malignancy. But no sign of the malignant tumor was found after endoscopy, 18-fluorine fluorodeoxyglucose positron emission tomography-computed tomography, and liver biopsy. The histopathology of the liver biopsy specimen indicated chronic inflammatory granuloma and then infectious diseases were suspected. However, traditional microbiologic testing failed to identify any potential pathogen. Eventually, metagenomic next-generation sequencing (mNGS) was applied to identify the definite diagnosis of liver cryptococcosis by acquiring the genome sequence of C. neoformans . Fortunately, after 6-month diagnostic anti-fungal therapy of fluconazole, the liver nodules effectively faded away and the serum CA19-9 level gradually regressed to the normal range. Conclusion We identified a rare case of hepatic cryptococcosis by mNGS in an immunocompetent patient. When conventional methods have difficulties in the diagnosis of a specific pathogen, mNGS has the advantage of early and accurate identification of potential pathogens from the specimen.

Clinical metagenomics-assisted diagnosis of relapsed HIV-associated cryptococcal meningitis

“…Previous studies have demonstrated the potential utility of mNGS for detecting Cryptococcus in the central nervous system, the pulmonary system, and the liver. [4][5][6] Yet, few studies have focused on using the method in differentiating between an IRIS and a relapse of cryptococcal meningitis. This study reports the use of mNGS to aid in diagnosing recurrent cryptococcal meningitis in a person living with HIV experiencing recurring symptoms, despite negative culture results for Cryptococcus neoformans in the cerebrospinal fluid.…”