The Hammock Sign in Computed Tomography as a Detection Aid for Bicuspid Aortic Valves.

Introduction: Bicuspid aortic valve is difficult to detect on standard transverse images. Purpose: We aimed to investigate the usefulness of the hammock sign for detection of bicuspid aortic valve. Methods: We retrospectively investigated the usefulness of a newly proposed 'hammock sign' in a population of 45 contrast enhanced computer tomographic studies to discern tricuspid (22) from anatomical bicuspid aortic (23) valves. The gold standard of aortic morphology was the definite diagnosis in the patient's medical file, established by computed tomography, magnetic resonance, or surgery. Results: Computer tomographic (CT) studies of each aortic morphology were randomly evaluated for the presence of the hammock sign on coronal and sagittal images, by two readers blinded to the diagnosis. Sensitivity for detecting an anatomic bicuspid valve was 86%, and specificity was 100%. Conclusion: The hammock sign allows for a quick and easy diagnosis of an anatomical bicuspid aortic valve, merely by scrolling through the standard coronal reconstructions of any type of contrast-enhanced thoracic CT study, and regardless of any other findings associated with bicuspid aortic valve. Functional bicuspid aortic valves were not the scope of this study.

Mucinous cystadenocarcinoma in the renal pelvis: primary or secondary? Case report and literature review.

INTRODUCTION: Cystic lesions in the renal pelvis may cause a diagnostic dilemma. These lesions may be benign or (pre)malignant and primary of secondary. CASE REPORT: A 65-year-old woman presents with a complex cystic mass in the lower pole of the left kidney measuring approximately 16 cm in size and classified as Bosniak type 2F with minimally thickened septa and thick calcifications on non-contrast-enhanced computed tomography. The histopathological findings are consistent with a mucinous cystadenocarcinoma in the renal pelvis. Given the absence of a primary focus and based on clinical and radiological examination, the diagnosis of a primary renal neoplasm is preferred. DISCUSSION: A review of the literature is performed to evaluate the histological differential diagnosis and confirm the diagnosis. Epidemiology with an overview of available similar cases since 2009, as well as etiological factors, treatment and prognosis was reviewed. CONCLUSION: Primary renal mucinous cystadenocarcinoma is an exceedingly rare tumor. Histopathology still remains the gold standard for the diagnosis of this tumor. Because of the rarity, secondary involvement from more common sites, such as ovary and gastrointestinal tract, should be thoroughly excluded.