Nav: Home

Researchers identify cause for lower-extremity overgrowths in obese patients

November 30, 2016

CHICAGO (November 30, 2016): Morbidly obese individuals--those whose weight is more than double normal weight--are prone to overgrowths in their lower extremities that can lead to infections and other health-threatening complications. Little was previously known about the underlying causes of this condition, and conventional treatment has involved surgical removal of these overgrowths. However, a new study published online as an "article in press" ahead of print in the Journal of the American College of Surgeons has identified the underlying cause for these overgrowths, and the researchers recommend that weight loss, not a surgical procedure, be the preferred initial treatment for these patients.

The researcher team, led by Arin K. Greene, MD, MMSc, FACS, a plastic surgeon at Boston Children's Hospital, Harvard Medical School, developed a probability scale that can help physicians identify patients at greatest risk of this condition, known as massive localized lymphedema (MLL). This study is the first to identify the cause of MLL as obesity-induced lymphedema (OIL), and it builds upon previous work Dr. Greene and colleagues have published in which they identified OIL as a disease resulting from obesity.*

"The major clinical takeaway for physicians is that if they have a patient with massive localized lymphedema, the individual has an underlying disease called obesity-induced lymphedema and the initial treatment should be weight loss," Dr. Greene said. "Surgeons should consider removing one of these massive growths only after the patient has lost significant weight, because the risk of recurrence is lower and the operation is much safer."

Body-mass index (BMI) is a measure that determines an individual's weight status. It is the ratio of one's weight in kilograms to the square of height in meters (kg/m2). BMI of 25 kg/m2 is considered normal, between 25.1 and 29.9 kg/m2 overweight, and 30 kg/m2 or greater obese. Once an individual's BMI exceeds 50 kg/m2, the lymphatic system in the legs becomes damaged and patients develop lower extremity swelling, known as obesity-induced lymphedema. Over time, massive overgrowths can occur in these patients; the higher the BMI, the greater the risk.

The Boston Children's-Harvard study involved 82 obese patients who underwent lymphoscintigraphy, a nuclear medicine test for evaluating lymph drainage, to evaluate lower extremity lymphatic function between 2009 and 2016. Seventeen were diagnosed with MLL, and all of them had underlying OIL. Their median BMI was 66 kg/m2, ranging from 62 to 78 kg/m2, with a median age of 61 years (median age of controls who did not have MLL was 55 years). Patients with a BMI greater than 56 kg/m2 had a 213 greater odds of developing MLL than patients with lower BMI. Dr. Greene pointed out that lymphoscintigraphy "is very accurate in determining if the lymphatic vessels in the lower extremities are functioning properly."

"An important finding of the study is that we can now counsel patients with OIL who have not yet developed MLL about the likelihood that they will develop MLL if they do not lose weight," Dr. Greene said. The study researchers developed a probability scale that identifies a patient's risk for developing MLL: a 4 percent chance at 40 kg/m2; 15 percent at 50 kg/m2; 40 percent at 60 kg/m2; 75 percent at 70 kg/m2; and 92 percent at 80 kg/m2.

The key is that morbidly obese patients with significant MLL overgrowths should undergo counseling for weight loss--non-surgical at first, then bariatric surgery if that fails--before undergoing an operation to remove the MLL overgrowths. "In our center, individuals with obesity-induced lymphedema, with or without MLL, are referred to a bariatric surgical center to treat the underlying cause of their lymphatic function, which is their weight," Dr. Greene said. "Not only will weight reduction prevent the occurrence of MLL, but it will significantly shrink the area of overgrowth and facilitate its resection."
Study coauthors are Reid Maclellan, MD, MMSC, of the Department of Plastic and Oral Surgery; David Zurakowski, PhD, of the Department of Anesthesia; and Frederick D. Grant, MD, of the Department of Radiology, Division of Nuclear Medicine, all at Boston Children's Hospital, Harvard Medical School.

Note: "FACS" designates that a surgeon is a Fellow of the American College of Surgeons.

Citation: Massive Localized Lymphedema: A Case-Control Study. Journal of the American College of Surgeons.

* Greene AK, Grant FD, Slavin SA. Lower-Extremity Lymphedema and Elevated Body-Mass Index. N Engl J Med. 2012; 366:2136-2137.

About the American College of Surgeons

The American College of Surgeons is a scientific and educational organization of surgeons that was founded in 1913 to raise the standards of surgical practice and improve the quality of care for surgical patients. The College is dedicated to the ethical and competent practice of surgery. Its achievements have significantly influenced the course of scientific surgery in America and have established it as an important advocate for all surgical patients. The College has more than 80,000 members and is the largest organization of surgeons in the world. For more information, visit

American College of Surgeons

Related Weight Loss Articles:

Cash for weight loss
A new study, published in the journal Social Science and Medicine, has shown that selling rewards programmes to participants entering a weight loss programme is a low cost strategy to increase both the magnitude and duration of weight loss.
Is alternate-day fasting more effective for weight loss?
Alternate day fasting regimens have increased in popularity because some patients find it difficult to adhere to a conventional weight-loss diet.
Bullies and their victims obsessed with weight-loss
School bullies and their victims are more obsessed with weight-loss than anyone else, according to new research by the University of Warwick.
Weight loss actually possible after menopause
Talk to a woman in menopause and you're likely to hear complaints about hot flashes and an inability to lose weight, especially belly fat.
Weight loss reduces psoriasis symptoms
Weight loss has a significant and prolonged positive impact on psoriasis symptoms and quality of life.
Weight loss may help prevent multiple myeloma
Carrying extra weight increases a person's risk that a benign blood disorder will develop into multiple myeloma, a blood cancer.
Gastric bypass is better than other procedures for sustainable weight loss
Gastric bypass surgery is more effective for weight loss and long-term weight maintenance than are other surgical procedures and non-surgical treatment, according to a study led by researchers at Duke Health and the Durham VA Medical Center.
Weight loss surgery associated with increased fracture risk
Severely obese patients undergoing weight loss surgery are more likely to have increased fracture risks both before and after the surgical procedure compared to obese and non-obese people people who don't need surgery, finds a large study published by The BMJ this week.
Online intervention helps sustain weight loss
New research, led by the University of Southampton, has found that an online behavioural counselling tool is effective at helping people lose weight.
Study compares effectiveness of weight-loss drugs
In an analysis that included nearly 30,000 overweight or obese adults, compared with placebo, orlistat, lorcaserin, naltrexone-bupropion, phentermine-topiramate, and liraglutide were each associated with achieving at least 5 percent weight loss at 52 weeks, and phentermine-topiramate and liraglutide were associated with the highest odds of achieving at least 5 percent weight loss, according to a study appearing in the June 14 issue of JAMA.

Related Weight Loss Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Digital Manipulation
Technology has reshaped our lives in amazing ways. But at what cost? This hour, TED speakers reveal how what we see, read, believe — even how we vote — can be manipulated by the technology we use. Guests include journalist Carole Cadwalladr, consumer advocate Finn Myrstad, writer and marketing professor Scott Galloway, behavioral designer Nir Eyal, and computer graphics researcher Doug Roble.
Now Playing: Science for the People

#529 Do You Really Want to Find Out Who's Your Daddy?
At least some of you by now have probably spit into a tube and mailed it off to find out who your closest relatives are, where you might be from, and what terrible diseases might await you. But what exactly did you find out? And what did you give away? In this live panel at Awesome Con we bring in science writer Tina Saey to talk about all her DNA testing, and bioethicist Debra Mathews, to determine whether Tina should have done it at all. Related links: What FamilyTreeDNA sharing genetic data with police means for you Crime solvers embraced...