"Periportal neoplasms"--a CT perspective: review article.

The periportal space is a potential space surrounding the portal vein and its intrahepatic branches. A variety of neoplasms can involve the periportal region, whether primary or secondary, owing to contiguous spread from surrounding hepatic parenchyma or from adjacent organs. CT plays an important role in not only diagnosing these lesions but also determining the extent of the disease. Most of the malignancies leading to the periportal spread manifest as periportal hypodensity either distinctly or in contiguity with the primary tumour. Even in known malignancies, periportal hypodensity commonly results from non-neoplastic causes like periportal oedema; hence, a knowledge of the imaging findings to ascertain its presence as well as to conclude the definite neoplastic spread is prudent. Periportal spread of neoplasm may suggest locally aggressive or disseminated disease (in extrahepatic malignancies), which may change management accordingly.