Observing liver hemangiomas yields important prognostic information

By James E. Barone MD

Almost 40% of hepatic hemangiomas show at least 5% growth linearly and over 44% grow more than 5% by volume over time, but about 45% shrink, says a new study.

Lead author Dr. Hani Y. Hasan, a general surgery resident at the Medical College of Wisconsin told Reuters Health, "The majority of hemangiomas change in size over time. Those that grow at or below the rates established by this study should not be a cause for concern or clinical intervention."

And Dr. Lewis R. Roberts, a professor of medicine at the Mayo Medical School in Rochester, Minnesota, told Reuters Health, "The study provides helpful information that will be useful for clinicians who are taking care of patients with hepatic hemangiomas that increase in size, by giving them an idea of the typical rate of increase in size and volume of hemangiomas."

The researchers analyzed 163 hemangiomas in 123 patients who presented during the years 1997 to 2007. For inclusion in the study, the lesions had to be 1 cm or larger on at least two imaging studies performed at least one year apart.

While both MRI and CT offer high resolution images that accurately characterize and measure these lesions, Dr. Hasan's group prefers MRI because it better delineates other benign lesions in the liver which are often present in patients with hemangiomas. He believes the choice of imaging modality depends on the technology available at each institution.

"Because of the opportunity to assess liver masses using other sequences beyond the multiphasic contrast scanning available by CT, MRI imaging is moving towards becoming the standard of care for evaluation of indeterminate liver masses," said Dr. Roberts, who has co-authored over 100 papers on liver disease but was not a part of this study.

Dr. Hasan said, "For consistency, it is preferred to use the same imaging modality when following a patient." Both he and Dr. Roberts feel that ultrasound is not accurate enough to determine small increases in size of hemangiomas over time.

Of the 163 lesions, 150 could be assessed with 3-dimensional software capable of measuring volume.

The 123 patients averaged 53.4 years of age; 70 (56.9%) were female. Follow-up averaged 3.7 years (range, 1 to 10.4 years). A solitary hemangioma was found in 74.8% of the patients, and 76.1% of hemangiomas were located in the right lobe of the liver.

As reported online in JAMA Surgery, the most common reasons for initial imaging were an examination or follow-up for malignancy (39.3%) and abdominal pain (29.5%).

Initially, the mean linear dimension of the hemangiomas was 3.2 cm and the volume averaged 137.8 cm³.

Just over half (50.9%) of the 163 hemangiomas grew linearly, 45.4% got smaller, and 3.7% were unchanged. Growth behavior by volume measurements was similar.

The authors opted to analyze only the 39.3% of hemangiomas that grew 5% or more in linear dimension or the 44.7% that grew 5% or more by volume to negate the effect of lesions that decreased in size. These hemangiomas grew linearly by 0.7 cm overall and had an annual growth rate of 0.19 cm, and by volumetric measurements grew by 184.3 cm³ and annually by 37.8 cm³ - which was an average growth of 17.7% per year.

The larger the lesion was initially, the greater were the overall linear and volumetric growth rates with R values of 0.617 and 0.750 respectively, p < 0.001 for both.

Growth of 5% or more occurred in only 46 (41.1%) of the 112 hemangiomas that were initially less than a mean of 3 cm in linear dimension compared to 9 (56.3%) of the 16 that were initially a mean of 5 cm or greater.

Overall and annual growth rates for hemangiomas averaging less than 3 cm in linear measurement were 0.04 cm and 0.065 cm respectively while lesions averaging greater than 5 cm linearly grew 1.4 cm overall and 0.37 annually.

Over time, hemangiomas grew uniformly, and annual growth rates did not correlate with the number of years between the first and last imaging studies (R = 0.00843, p =0.92).

"Once a hemangioma is diagnosed with high resolution axial imaging, repeat imaging should be performed once in 6-12 months to confirm the diagnosis and establish if significant growth has occurred," said Dr. Hasan. Rapidly growing lesions might need repeat imaging every 6 to 12 months, but data from the current study did not address that issue.

"For lesions growing at the rate reported in this study, serial imaging should be done based only on clinical symptoms," Dr. Hasan said.

Dr. Roberts agreed with the Wisconsin researchers' recommendations but said, "If the imaging features of a 'hemangioma' are in any way atypical, I usually recommend close follow up and/or biopsy to confirm the diagnosis, as I have seen a number of 'atypical hemangiomas' that turned out to be malignant lesions."

SOURCE: http://bit.ly/1ufWldx

JAMA Surgery 2014.

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