An Unusual Case of Suspected Metastatic Gastrointestinal Stromal Tumor Complicated by Streptococcus Intermedius Pyogenic Liver Disease.

A gastrointestinal stromal tumor (GIST) is a mesenchymal neoplasm of the gastrointestinal tract often known to express c-KIT or platelet-derived growth factor receptor alpha (PDGFRα). Among all GI tract cancers, they account for less than 1% of cases. Most patients become symptomatic in the later stages of the tumor's course, often presenting with insidious anemia due to gastrointestinal bleeding and metastasis. The recommended management of solitary GIST is surgery, while larger or metastatic tumors that express c-KIT are managed with imatinib as either neoadjuvant or adjuvant therapy. Due to the progression of these tumors, they are at times associated with systemic anaerobic infection, which is an indication of malignancy workup. In this case report, we discuss a 35-year-old woman who was discovered to have GIST with possible hepatic metastasis complicated by pyogenic liver disease due to Streptococcus intermedius and the diagnostic challenge of differentiating between infection and tumor.

Fusobacterium nucleatum Pyogenic Liver Abscess and the Role of Bacterial Virulence and Gut Microbiota Dysbiosis.

In the United States, pyogenic liver abscesses are often due to monomicrobial infection and are rarely documented to be a consequence of Fusobacterium infection, a common cause of Lemierre's syndrome. Recent advances in gut microbial studies have identified Fusobacterium as a commensal gut flora that becomes pathogenic in the setting of dysbiosis resulting from colorectal diseases, such as diverticulitis. While the bacteria's tropism for the liver remains to be elucidated, the virulence pattern of Fusobacterium and the portal venous drainage system have allowed us to understand the bacterium's propensity for causing right hepatic abscesses. In this case report, we detail an immunocompetent man with a history of sigmoid diverticulitis who developed a right hepatic abscess due to Fusobacterium nucleatum, while delineating a review of the literature on the virulent properties of the bacterium and the impact of gut microbiota dysbiosis in its pathogenicity. A descriptive analysis was also performed to identify the characteristics of patients who are at risk in hopes of further improving the clinical diagnostic schema for this condition.