Cystic liver metastases from colorectal cancer

An Analysis of Clinicopathological Outcomes and the Utility of Preoperative MRI for Patients Undergoing Resection of Mucinous and Non-Mucinous Colorectal Cancer Liver Metastases

Background and Aims

Mucinous colorectal cancer has traditionally been associated with high rates of recurrence and poor long-term survival. There is limited published data on outcomes for patients undergoing liver resection for metastatic mucinous colorectal cancer. The aim of this study was to compare the clinicopathological outcomes for patients with mucinous colorectal cancer liver metastases (CRCLM) undergoing liver resection to a matched group of patients with adenocarcinoma not otherwise specified (NOS) and to evaluate the accurary of preoperative magnetic resonance imaging (MRI) at detecting the presence of mucin in liver metastases.

Materials and Methods

Patients with mucinous CRCLM undergoing liver resection were matched 1:3 to patients with adenocarcinoma NOS CRCLM. Clinicopathological data from the primary tumour and metastatic lesion were collected and compared between the groups. Hepatic recurrence-free, disease-free and overall survival were compared between the groups. The ability of preoperative MRI to detect mucin in CRCLM was also evaluated.

Results

A total of 25 patients with mucinous CRCLM underwent surgery over the 12-year period and were matched to 75 patients with adenocarcinoma NOS. Clinicopathological findings were similar between the groups. Resection of mucinous CRCLM was feasible and safe with similar levels of morbidity to adenocarcinoma NOS. There were no differences identified in hepatic recurrence-free (p=0.85), disease-free (p=0.25) and overall survival (p=0.98) between the groups. MRI had a sensitivity of 31.3% in detecting the presence of mucin in CRCLM.

Conclusion

Patients with mucinous CRCLM in this study had similar outcomes to patients with adenocarcinoma NOS. Based on our findings, histological subtype should not be taken into account when deciding on resectability of CRCLM.

[Computed tomography and/or magnetic resonance imaging of the liver : How, why, what for?]

CLINICAL PROBLEM

Colorectal metastases are the most common malignant liver lesions. Imaging of the liver in patients with colorectal carcinoma is performed for early detection of liver metastases (CRLM) at the time of initial tumor diagnosis, for monitoring and follow-up in order to exclude or diagnose metachronous metastases.

STANDARD RADIOLOGICAL METHODS

Radiological imaging includes primarily multislice computed tomography (CT) and magnetic resonance imaging (MRI), which play an important role regarding therapeutic management and assessment of prognosis.

PERFORMANCE, ACHIEVEMENTS

Contrast-enhanced CT is broadly available and allows for rapid image acquisition including the possibility for complete tumor staging. MRI, on the other hand, is characterized by very good soft tissue contrast and has-especially with the use of diffusion-weighted imaging and administration of liver-specific contrast agents-the highest sensitivity for detection of metastases smaller than 1 cm.

PRACTICAL RECOMMENDATIONS

The choice of imaging in daily routine is often dependent on availability and clinical question. Frequently, e.g. for assessment of resectability (extent of metastases, anatomic relation of lesions to critical structures), both modalities may be implemented in combination.

Differentiating metastatic mucinous colorectal adenocarcinomas from simple cysts of the liver using contrast-enhanced and diffusion-weighted MRI

OBJECTIVE:

To determine the value of contrast-enhanced and diffusion-weighted (DW) MRI for differentiating metastatic mucinous colorectal adenocarcinomas from simple cysts of the liver.

METHODS:

29 patients with 47 metastatic mucinous colorectal adenocarcinomas and/or 19 simple cysts of the liver who underwent contrast-enhanced and DW MRI were included in this retrospective study. Two radiologists assessed the MRI findings by consensus. Qualitative and quantitative analyses were conducted. Significant MRI findings on univariate and multivariate analyses were assessed, and their diagnostic performances for predicting metastatic mucinous colorectal adenocarcinomas were analyzed.

RESULTS:

The presence of rim enhancement (odds ratio, 28.43; p = 0.008) and intracystic enhancement (oddsratio, 180.15; p = 0.001) were independently significant factors for predicting metastatic mucinous colorectal adenocarcinomas. The sensitivity and specificity of rim enhancement, intracystic enhancement, and their combination for detecting metastatic mucinous colorectal adenocarcinomas were 83% (39/47) and 63.2% (12/19), 87.2% (41/47) and 89.5% (17/19), and 72.3% (34/47) and 94.7% (18/19), respectively. Compared to simple cysts, metastatic mucinous colorectal adenocarcinomas showed significantly lower mean apparent diffusion coefficient (1.92 ± 0.81 vs 2.99 ± 0.75 × 10^-3 mm² s^-1; p = 0.001) and lesion-to-liver apparent diffusion coefficient ratio (1.66 ± 0.75 vs 2.44 ± 0.56 × 10^-3 mm² s^-1; p = 0.004) and higher mean signal intensity (400.3 ± 216.3 vs 222.4 ± 99.3; p = 0.039) and lesion-to-liver signal intensity ratio on hepatobiliary-phase images (0.58 ± 0.16 vs 0.30 ± 0.14; p < 0.001).

CONCLUSION:

Contrast-enhanced and DW MRI may be helpful for differentiating metastatic mucinous colorectal adenocarcinomas from simple cysts of the liver.

ADVANCES IN KNOWLEDGE:

On contrast-enhanced and DW MRI, rim and intracystic enhancement can be helpful for differentiating metastatic mucinous colorectal adenocarcinomas from simple cysts of the liver.

Cystic Liver Metastases from Lung Adenocarcinoma: A Case Report

Cystic hepatic metastases arising from lung cancer are rare. We herein describe a case of a 71-year-old women admitted to our hospital for abdominal pain 6 months after the resection of a lung adenocarcinoma. Two cystic lesions of the liver were discovered at abdominal ultrasonography and computerized tomography scan. An ERCP excluded a biliary adenoma or adenocarcinoma, and an ultrasound-guided liver biopsy was negative for malignant cells. For persistence of symptoms and lack of a diagnosis, the patient underwent an exploratory laparotomy, a surgical biopsy with a diagnosis of adenocarcinoma, and a consequent right hepatectomy. After 2 years of follow-up, the patient is well and disease free. Although cystic liver metastasis are rare and a differential diagnosis difficult, the malignant nature should always be considered in the differential diagnosis of hepatic cysts to offer the patient the best treatment.

Prevalence of hepatic lesion types defined by T2-weighted and dynamic gadolinium-enhanced MR imaging in patients with metastasized neuroendocrine tumors

PURPOSE

Identifying liver metastases from neuroendocrine tumors (NETs) is a pretherapeutic challenge in patients who are candidates for liver resection. The aims of our study are to characterize and determine the frequency of different MRI characteristics of liver metastases caused by NETs in a lesion-by-lesion analysis and to determine the frequency of monomorphous and polymorphous metastases in a patient-by-patient analysis.

METHODS

This retrospective study involved 47 patients with liver metastases arising from histologically confirmed NETs. In a lesion-by-lesion analysis, we classified these metastases according to their MRI characteristics as follows: hypervascular lesions with homogeneous or peripheral enhancement, hypovascular lesions, pure cystic lesions, and mixed solid/cystic lesions. In the patient-by-patient analysis, we distinguished patients whose metastases had the same MRI characteristics from patients with mixed lesion characteristics.

RESULTS

A total of 376 metastases were analyzed. Of these, 84.3% (n = 317) were hypervascular, with 51.9% showing homogeneous enhancement and 32.4% (n = 122) showing peripheral enhancement. Another 7.4% (n = 28) were hypovascular, 5.3% (n = 20) were pure cystic, and 2.9% (n = 11) were mixed solid/cystic. After excluding three patients with solitary lesions, 40.9% of patients (n = 18) had mixed-type lesions, consisting of hypervascular lesions with either homogeneous or peripheral enhancement in 27.3% of cases (n = 12), while 59.1% of patients (n = 26) had identical lesions.

CONCLUSION

Approximately 15% of metastases have atypical MRI characteristics and are either hypovascular or cystic. Metastases with different MRI characteristics coexist in 40% of patients.

Rectal melanoma presenting as a solitary complex cystic liver lesion: role of contrast-specific low-MI real-time ultrasound imaging

Cystic hepatic metastases arising from malignant melanoma are extremely rare, with the few such cases reported in the literature to date describing indeterminate imaging findings, being focused more on computed tomography. To the best of our knowledge, there is no prior report describing contrast-enhanced ultrasound findings of a solitary cystic liver metastasis from a primary rectal melanoma. We herein describe a case of a 41-year-old patient with a rectal melanoma, in whom the first manifestation of disease was a solitary complex cystic liver metastasis incidentally detected by ultrasound. On admission, our patient was free of specific symptoms and his laboratory test was normal. In this setting, contrast-enhanced ultrasound showed some distinctive features that helped us to make the correct diagnosis, confirmed subsequently by FNAC examination, thus allowing to provide the correct management for our patient. Although cystic metastases are rare, knowledge of CEUS imaging findings will be invaluable for radiologists and other medical subspecialties that may face such cases in the future in helping to provide adequate management for affected patients.

Benign metastasizing pleomorphic adenoma in liver mimicking synchronic metastatic disease from colorectal cancer: a case report with emphasis on imaging findings

Pleomorphic adenoma of the parotid gland with metastases to the liver is a rare etiology of focal liver lesions, and there are no described pathognomonic imaging features. We report a patient who presented with a newly diagnosed rectal cancer and multiple cystic liver lesions suspicious of mucinous synchronous liver metastases. Following chemotherapy no reduction in the number or size of the liver lesions was observed. The patient was re-evaluated and a biopsy of a lesion was performed. The specimen showed a metastasis from a pleomorphic adenoma of the parotid gland for which the patient had been treated 20 years earlier. The case illustrates how a thorough medical history can be crucial when a standard diagnostic imaging workup for colorectal cancer metastases is uncertain, and how a biopsy, though regarded as contraindicated due to the risk of tumor cell dissemination, can be required to secure a correct diagnosis.

Intracystic concentrations of tumour markers for the diagnosis of cystic liver lesions

BACKGROUND

Imaging occasionally fails to differentiate hepatic simple cysts from malignant or premalignant mucinous cystic lesions such as biliary cystadenomas. Hepatic simple cysts can be treated conservatively, whereas malignant or premalignant cysts require complete resection. This study assessed the ability of intracystic tumour marker concentrations to differentiate these disease entities.

METHODS

Intracystic fluid was sampled in patients undergoing partial or complete resection of a cystic lesion of the liver. The indication for surgery in hepatic simple cysts was symptoms or suspicion of a biliary cystadenoma. Intracystic concentrations of carcinoembryonic antigen (CEA), carbohydrate antigen (CA) 19-9 and tumour-associated glycoprotein (TAG) 72 were measured to assess the diagnostic accuracy of these tumour markers. Cut-off values were defined by receiver operating characteristic (ROC) curves.

RESULTS

The study population comprised 118 patients (94 women) with a median age of 59 years. There were 75 patients with hepatic simple cysts, 27 with mucinous cysts (19 biliary cystadenomas, 4 biliary cystadenocarcinomas, 4 intraductal papillary mucinous neoplasms of the bile duct) and 16 with miscellaneous cysts. Unlike CEA and CA19-9, a TAG-72 concentration of more than 25 units/ml differentiated hepatic simple cysts from mucinous cysts with a sensitivity and a specificity of 0·79 and 0·97 respectively. The area under the ROC curve was 0·98 for mucinous versus hepatic simple cysts.

CONCLUSION

The concentration of TAG-72 in cyst fluid accurately identified hepatic cysts that required complete resection.

Imaging features of colorectal liver metastasis in FDG PET-CT: a retrospective correlative analysis between CT attenuation and FDG uptake

OBJECTIVES

Increasing scientific evidence supports the use of fluorodeoxyglucose positron emission tomography/ computed tomography (FDG-PET/CT) in the staging of colorectal carcinoma. A detailed and accurate characterization of tumor biology and imaging characteristics is therefore of paramount importance. The aim of our study was to determine whether CT attenuation, in Hounsfield units, was correlated with FDG uptake in colorectal liver metastasis.

METHODS

The clinical and imaging data of patients from our institution with histologically proven colorectal carcinoma who were referred for PET/CT staging were reviewed. For the purpose of our study, we included only those patients who had undergone dual-time-point imaging. A total of 20 patients with 62 hepatic secondaries were identified. The perlesional CT attenuation (in Hounsfield units), FDG uptake (in standardized uptake values SUV 60 and SUV 120), and size (in cm) were determined. Correlation analysis using the Spearman rank correlation coefficient was carried out.

RESULTS

A statistically significant positive relationship was observed between perlesional CT attenuation and SUV 60 (r=0.433, P=0.0004). A similar significant positive relationship was shown between perlesional CT attenuation and SUV 120 (r=0.414, P=0.0008).

CONCLUSION

Our study suggested that, in colorectal liver metastasis, FDG uptake was positively correlated with CT attenuation. If a lesion appeared to be indeterminate because of apparently low FDG avidity, internal content must be taken into consideration to minimize misdiagnosis and false negatives. We proposed that such a relationship may be due to the mucinous contents of colorectal liver metastasis or degree of tumor necrosis. Further research, particularly on quantification of the extent of mucin production and tumor necrosis, may allow a more precise relationship to be drawn between CT attenuation and FDG uptake.

Small colorectal cystic metastases to the liver: still a diagnostic dilemma? A report of a case and a review of the literature

BACKGROUND

Although cystic colorectal metastases are rare (1.8%), they are still a crucial challenge for the surgeon especially in terms of detection and differential diagnosis. Since prognosis after resection is very good (40% 5-year survival), early diagnosis is essential.

CASE REPORT

A 55-year-old man was admitted to our hospital with a suspected diagnosis of multiple small liver metastases. He had previously undergone left sided-cholectomy followed by chemotherapy for colonic carcinoma. Computed tomography (CT) revealed multiple small (<15 mm) intrahepatic biliary cysts, suspected for cystic colorectal liver metastases.

CONCLUSION

The diagnosis of cystic colorectal liver metastases is quite difficult and it is mostly based on the last-generation magnetic resonance (MR). In spite of this, we must often rely on histological results for a definitive diagnosis.

[Imaging of cystic liver diseases]

The high frequency of benign and asymptomatic liver cysts must not underevaluate the potential diagnostic difficulties of liver cystic diseases. Complicated liver cyst or cystic mass of various origin, such as developmental, neoplastic or inflammatory, are important to be recognized by the radiologist. The diagnostic approach is depending on the number of lesions and their dissemination. The presence of a wall, the internal structure of the lesion, particularly the MR signal and the proximity of the biliary tree are the main diagnostic criteria. Some less frequent but characteristic unusual features need to be memorized.

Biliary cystadenoma of the left intrahepatic duct (2007: 2b)

Biliary cystadenoma is a rare epithelial cystic neoplasm representing only 5% of intrahepatic cystic lesions of biliary origin. Commonly, the lesions are solitary cystic structures with multiple thin-walled septa predominantly arising from the right hepatic duct. Although the lesions are generally intrahepatic, extrahepatic tumors have been reported. Biliary cystadenomas range in diameter from 1.5 to 35 cm. The tumor usually affects middle-aged women. Clinical symptoms are related to the mass effect and comprise episodes of jaundice due to biliary obstruction and intermittent upper abdominal pain. Laboratory parameters are nonspecific. As the tumor is considered a premalignant lesion, complete surgical resection is the treatment of choice. We report a case of typical biliary cystadenoma of the left hepatic duct.

Cystic focal liver lesions in the adult: differential CT and MR imaging features

Cystic lesions of the liver in the adult can be classified as developmental, neoplastic, inflammatory, or miscellaneous. Although in some cases it is difficult to distinguish these entities with imaging criteria alone, certain cystic focal liver lesions have classic computed tomographic (CT) and magnetic resonance (MR) imaging features, which are important for the radiologist to understand and recognize. Lesions with such features include simple (bile duct) cyst, autosomal dominant polycystic liver disease, biliary hamartoma, Caroli disease, undifferentiated (embryonal) sarcoma, biliary cystadenoma and cystadenocarcinoma, cystic subtypes of primary liver neoplasms, cystic metastases, pyogenic and amebic abscesses, intrahepatic hydatid cyst, extrapancreatic pseudocyst, and intrahepatic hematoma and biloma. Specific CT and MR imaging findings that are important to recognize are the size of the lesion; the presence and thickness of a wall; the presence of septa, calcifications, or internal nodules; the enhancement pattern; the MR cholangiographic appearance; and the signal intensity spectrum. In addition, access to critical clinical information remains extremely important. The most important clinical parameters defined include age and gender, clinical history, and symptoms. An understanding of the classic CT and MR imaging appearances of cystic focal liver lesions will allow more definitive diagnosis and shorten the diagnostic work-up.