A Common Presentation of Right Upper Quadrant Pain in an Uncommon Disease

Abstract

The presentation of right upper quadrant abdominal pain is common, non—specific and challenging to diagnose. Right upper quadrant (RUQ) pain can be benign but may also signal serious pathology. Early diagnosis is key to preventing possible complications. This case aims to highlight a presentation of RUQ pain in a young male which heralded a more sinister pathology. A previously healthy 36year—old male presented with one—week of intermittent fevers and progressive sharp RUQ pain with chills, night sweats, early satiety and fatigue. Initial assessment was significant for HR 116, RUQ tenderness with guarding, no rebound or organomegaly. Laboratory findings were only significant for lactate 11.08mg/dL. Cultures were negative, AFP was normal. HIV, HBV and HCV were negative.Abdominal ultrasound revealed heterogeneous large right hepatic lobe mass suggestive of hemorrhage, hepatic adenoma, metastasis, fibrolamellar hepatocellular carcinoma (HCC) or hepatic abscess. MRI with contrast had similar findings with large non—enhancing geographic regions, T2—hyperintense and T1—hypointense, consistent with necrosis or blood products. MRI was suggestive of atypical HCC, fibrolamellar HCC, angiosarcoma or metastases; hepatic adenoma unlikely in the absence of risk factors. CT—guided biopsy revealed hepatic neoplasm favoring adenoma with atypical findings evidenced by immunostaining, diffuse strong glutamine synthetase staining and no nuclear beta—catenin staining, positive serum amyloid A, and retained LFABP. Glutamine synthetase staining was concerning for beta—catenin invasion. He underwent a right hepatic lobectomy, with pathology finding of hepatic adenoma, and no recurrence at 1—year follow—up. Hepatocellular adenomas (HCA) are rare, benign tumors which occur mostly in women and are strongly associated with the use of estrogens, anabolic and androgenic steroids. There are no specific diagnostic serologic or imaging studies. The new Bordeaux HCA subtype classification is based on genetic and phenotypic characteristics and provides insight into the pathological and radiological diagnosis and clinical management. Complications such as rupture, hemorrhage and malignant transformation to HCC increase mortality markedly. Mortality is low when recognized and treated early. It is, therefore, an important differential to consider in a patient with RUQ pain in the presence of a liver mass with no underlying cirrhosis. The absence of risk factors does not exclude the diagnosis.3020_A.tif Figure 1: Abdominal ultrasound: Large heterogeneous right hepatic lobe mass with suggestion of internal hemorrhage.3020_B.tif Figure 2: Contrast—MRI, coronal and axial views: marked enlargement of the right hepatic lobe secondary to a large mass with intrahepatic blood products suggesting rupture/hemorrhage3020_C.tif Figure 3: Liver biopsy histology: Hepatocellular neoplasm, favor adenoma with atypical findings. Diffuse strong glutamine synthetase staining, serum amyloid A positive, retained LFABP, no nuclear beta—catenin staining and noncontributory reticulin special stain