Appearances of von Meyenburg Complex on Cross Sectional Imaging
An 81-year-old man was admitted with a one-week history of abdominal pain and constipation. On clinical examination, there was abdominal distension and guarding in the right abdomen. Contrast-enhanced CT images (Siemens Sensation 16 slice) were acquired in the portal venous phase (60 s following administration of contrast), demonstrating a focal sigmoid stricture and proximal large bowel obstruction. Multiple low-density lesions of varying sizes were identified within the liver, which were non-enhancing in the portal venous phase []. A sigmoid malignancy was likely, but the majority of liver lesions were near fluid density (3-20HU) and not entirely typical for metastases.\nB-mode ultrasound demonstrated multiple hyperechoic lesions [] of varying sizes throughout the liver, none of which displayed signal with color Doppler ultrasound. The hepatic lesions were further interrogated with CEUS, using Sonovue™ (Bracco SpA Milan) as the microbubble contrast agent, on a Siemens S2000 (Siemens AG, Erlangen), with a 4 MHz transducer and imaged using a low mechanical index technique (CPS™, Siemens AG, Erlangen). No appreciable vascularity was seen within the hepatic lesions in all three phases of the study (arterial, early portal venous, and late portal venous phase) with imaging performed for 3 min []. The patient proceeded to laparotomy where a Hartmann's procedure was performed and multiple liver biopsies were obtained.\nHistology of the resected colon confirmed moderately differentiated adenocarcinoma invading through the muscularis propria, but not penetrating the serosal surface. No involvement of the regional lymph nodes was identified. Liver biopsies revealed normal background hepatic parenchyma. Histology of the focal lesions demonstrated expanded portal tracts with dense stroma, containing dilated bile ducts; a few of which contained inspissated bile []. A dilated congested blood vessel within the specimens was presumed to be responsible for the hepatic nodularity. The appearances were in keeping with a diagnosis of VMC.\nMR imaging was performed to further evaluate the liver and to identify any lesions characteristic of metastases. Multiple hepatic lesions were again visualized and displayed moderate to high T2 (TR: 2410; TE: 103) signal intensity [] and T1 hypointensity with no contrast enhancement []. The multiple liver lesions displayed decreasing signal intensity [] with increasing b-values on diffusion-weighted imaging, indicating free diffusion. The imaging findings were in keeping with VMC in addition to simple cysts; metastases being less likely.\nThe patient had an uncomplicated post-operative course and was discharged. Surveillance imaging 3 years post-surgery demonstrated identical appearances of the liver, with no new abnormalities present and no disease recurrence.