Faculty Bibliography

Miscellaneous tumour-like ovarian lesions are histobiologically diverse, and are often mistaken for the more common ovarian cancers, leading to aggressive management. Knowledge of characteristic clinical, laboratory and imaging findings of these select non-neoplastic ovarian entities allows correct diagnoses and permits optimal management.

Pancreatic endocrine neoplasms are rare pancreatic tumours that may occur sporadically or as part of inherited syndromes such as multiple endocrine neoplasia-1 syndrome, von Recklinghausen disease, von Hippel-Lindau syndrome and tuberous sclerosis complex. Recent advances in the genetics and pathology of hereditary syndromes have provided valuable insights into the pathophysiology and biology of sporadic pancreatic endocrine neoplasms. Evolving molecular data on the biology of these neoplasms have the potential for diagnostic, therapeutic and prognostic use.

Laparoscopic adjustable gastric banding (LAGB) is performed with increasing frequency for the management of morbid obesity. Although LAGB is less invasive than other bariatric surgical procedures, it is associated with various complications that may lead to nonspecific abdominal symptoms several months or years after the procedure. Because complications of LAGB may be encountered incidentally at imaging for other indications, all radiologists should be familiar with the appearances of correctly positioned and malpositioned gastric bands, normal and abnormal appearances of the postprocedural pouch and stomach, and imaging features suggestive or indicative of early or delayed complications of LAGB. Familiarity with the techniques and systems currently approved by the Food and Drug Administration for use in this procedure may help radiologists detect postoperative complications and guide their management. Both commercially available systems include a silicone gastric band with an inflatable inner surface, a reservoir port, and a tube that connects the port to the gastric band. All these components of LAGB systems should be visible at radiologic imaging; however, older models of gastric bands may not be radiopaque and therefore may not be depicted on images. The most common complications of LAGB are gastric band slippage and associated pouch dilatation, intragastric erosion of the band, gastric perforation, and abscess formation. Complications that occur with less frequency include tube migration, tube disconnection, port-site infection, and small bowel obstruction.

Recent advances in genetics and pathology have allowed description of several new histological subtypes of renal cell carcinoma (RCC) as well as better characterization of other rare subtypes. We herein present a comprehensive review of taxonomy, epidemiology, pathology, imaging findings, and natural history of a wide spectrum of rare subtypes of RCCs that individually constitute <1% of all the RCCs.

Immunological diseases of the hepatobiliary system and the pancreas include a broad spectrum of disorders that manifest characteristic histopathology/serology and variable clinical features and imaging findings. Recent studies have thrown fresh light on the complex role of genetics and autoimmunity in the pathogenesis and natural history of these diverse disorders that include autoimmune hepatitis, primary biliary cirrhosis, primary sclerosing cholangitis, IgG4-related cholangitis, overlap/outlier syndromes, and autoimmune pancreatitis.

There is a diverse group of rare, primary benign and malignant ovarian tumors that show characteristic histomorphology and natural history. Some of these tumors may demonstrate typical imaging features. However, due to the rarity of these tumors, imaging characteristics of these diverse lesions are not well described in the literature. Knowledge of these select ovarian entities is essential and facilitates optimal management of patients who often manifest with nonspecific symptoms.

Sclerosing cholangitis can be idiopathic (primary) or secondary to an identifiable cause. Irrespective of cause, sclerosing cholangitis usually progresses to end-stage liver disease and warrants orthotopic liver transplantation. Recent studies provide new insights into the etiopathogenesis, natural history, diagnosis, and management of these different entities.

Hepatocellular adenomas are benign liver neoplasms with specific but varied histopathologic findings and tumor biology. The results from recent studies of the pathologic and genetic basis of hepatocellular adenomas provide important insights into the pathogenesis and molecular changes, as well as the putative oncologic pathways used by diverse adenoma subtypes. On the basis of the genetic and pathologic features, hepatocellular adenomas are categorized into three distinct subtypes: (a) inflammatory hepatocellular adenomas, (b) hepatocyte nuclear factor 1 alpha-mutated hepatocellular adenomas, and (c) beta-catenin-mutated hepatocellular adenomas. Different subtypes show variable clinical behavior, imaging findings, and natural history, and thus the options for treatment and surveillance may vary. Cross-sectional imaging plays an important role in the diagnosis, subtype characterization, identification of complications, and surveillance of hepatocellular adenomas. New schemas for genotype-phenotype classification of hepatic adenomas, as well as management triage of patients with specific subtypes of adenomas, are being proposed in an attempt to improve clinical outcomes.

OBJECTIVE: There is a wide spectrum of nonneoplastic causes of biliary stricture that can pose a significant challenge to clinicians and radiologists. Imaging plays a key role in differentiating benign from malignant strictures, defining the extent, and directing the biopsy. We describe the salient clinical and imaging manifestations of benign biliary strictures that will help radiologists to accurately diagnose these entities. CONCLUSION: Accurate diagnosis and management are based on correlating imaging findings with epidemiologic, clinical, and laboratory data. Cross-sectional imaging modalities permit precise localization of the site and length of the segment involved, thereby serving as a road map to surgery, and permit exclusion of underlying malignancy.

OBJECTIVE: This article provides a comprehensive review of the role of MDCT and MRI in the diagnosis of drug-induced complications in the abdomen and pelvis in adults. A systematic organ-based review of these complications is presented, including but not limited to hepatic changes after chemotherapy, renal complications such as tumor lysis syndrome and lithium nephropathy, gastrointestinal manifestations, various opportunistic infections and secondary neoplasms, mycotic aortic aneurysm from intravesical bacille Calmette-Guerin, complications of anticoagulant therapy, and oral contraceptives. CONCLUSION: Advancements in imaging have led to recognition of radiologic features of previously unsuspected diseases. Occasionally, imaging may also identify effects of treatments instituted for these diseases. Consequently, imaging plays a critical role in the accurate diagnosis of a broad spectrum of drug-induced complications in the abdomen, both in emergent and nonemergent settings. Knowledge of the natural history, clinical manifestations, and salient imaging features of these entities is crucial to facilitate accurate clinical diagnosis in a timely fashion.