The purpose of this retrospective study was therefore to evaluate the imaging features at cross-sectional imaging in a series of patients with solitary necrotic nodule of the liver, and to describe the natural evolution at follow-up for 2-6 years after histologic diagnosis. Two of these patients were included in an earlier report that focused on the imaging features [16] but not on the natural history of the nodules. Materials and Methods PatientsThe imaging examinations of nine patients with pathologically proven solitary necrotic nodule of the liver were included in this study. Proof of diagnosis was based on findings at core-biopsy performed with an 18-gauge needle (n = 6) or at liver resection (n = 3). Cases were collected from four university hospitals over a 6-year period and were identified by reviewing pathology databases.In our patients, solitary necrotic nodules were incidentally detected on cross-sectional imaging performed for various reasons, such as staging in patients with extrahepatic primary malignancies (n = 3), abdominal pain (n = 3), and suspected gallbladder (n = 2) or urinary (n = 1) stones. Institutional review board approval and patient consent were not required for this retrospective study because patient privacy was maintained and patient care was not impacted. H e p a t o b i l i a r y I m ag i ng • C l i n ic a l O b s e r v a t io -6]. At pathology, it is characterized by a necrotic central core surrounded by a dense hyalinized fibrotic capsule. Previous authors have shown that solitary necrotic nodule of the liver has sometimes been misinterpreted as malignant [5][6][7][8], leading to inappropriate treatment. To that end, awareness and recognition of this entity have important implications for patient care to avoid errors in management. The existing knowledge of the imaging features of solitary necrotic nodule of the liver is gleaned mostly from articles describing one or two patients [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20], and the only case series investigates the imaging features of solitary necrotic nodules of the liver with histopathology [4,7] or sonography only [21]. To our knowledge, no case series describing the imaging features of solitary necrotic nodules with cross-sectional imaging has been reported except an article that was recently published in the non-English-language literature [22]. Moreover, because the numbers of patients with solitary necrotic nodule of the liver are small, no information exists on the natural history. With the nine patients with solitary necrotic nodule of the liver reviewed here, we will expand on the information gained from prior studies. Imaging Protocols and Methods