Soft tissue sarcomas are often misdiagnosed as benign masses. The two can present in a similar manner, as painless, growing soft tissue lumps or bumps. However, misdiagnosis of the rare, soft tissue sarcoma can have devastating consequences.
“Every year in the United States, approximately 10,000 soft tissue sarcomas are diagnosed; the rarity of this cancer likely contributes to physicians’ lack of heightened awareness of it,” said Ginger Holt, M.D., chief of the Division of Musculoskeletal Oncology at Vanderbilt University Medical Center.
“In today’s era of rapid communication and accessible information, modern physician education regimes should have overcome that.”
The most common mistake by physicians who are less experienced with diagnosing soft tissue sarcomas is assuming that all masses are lipomas, which, although underdiagnosed, occur in about 1 percent of the United States population.
“Benign fatty masses, or lipomas, are indeed extremely common, but physicians must comply with the standard of care. All soft tissue masses are not lipomas,” Holt emphasized.
In an educational review published in Instructional Course Lectures, a publication of the American Academy of Orthopaedic Surgeons, titled “Soft Tissue Masses: A Visual Guide to the Good, the Bad and the Ugly,” Holt and colleagues explain the need in these cases for a careful patient history, thorough physical examination, and appropriate imaging to determine the benign or malignant nature of a tumor.
Exam and Imaging Guidelines
Holt and colleagues say certain physical exam findings should raise suspicions of a malignancy. These include a mass of 5 centimeters or greater in size; a perceptible firmness in the mass compared to surrounding tissue; deep extension into the investing fascia; and any signs of growth.
“Following these simple guidelines is the ideal way to initially assess these tumors,” Holt said. “If the patients don’t get a proper evaluation and have a ‘whoops’ surgery, where a sarcoma has been incompletely excised, they often have to get at least one more surgery, which causes substantial physical and emotional difficulties, and can change their functional outcomes and overall survival.”
“Benign fatty masses, or lipomas, are indeed extremely common, but physicians must comply with the standard of care. All soft tissue masses are not lipomas.”
The researchers added that the gold standard for distinguishing soft tissue masses is an MRI scan and that superficial masses of 5 centimeters or smaller with a soft texture do not usually require imaging as a first step but do need short-interval follow-up. They also noted that up to 32 percent of soft tissue sarcomas can present initially as small, superficial masses.
“Unfortunately, soft tissue sarcomas often don’t fit the algorithms used by insurance companies to authorize MRIs,” Holt explained. “Thus, even if a physician orders an MRI scan for differential diagnosis, it may be denied.”
Center for Specialized Care
“Many studies have demonstrated that patients have much better outcomes – surgical outcomes, functional outcomes and longevity outcomes – when they go to a center of excellence or center specializing in sarcoma,” Holt said. “At Vanderbilt, we have multidisciplinary collaborations, including medical oncology specialists, radiation specialists, and sarcoma pathology specialists. We meet weekly to discuss cases, ensuring patients receive proper evaluation and appropriate treatment.”
Holt is an educational speaker, as well as a writer and advocate for basic training on soft tissue masses to physicians of all specialties. She also engages with insurance and third-party reviewers to raise awareness about the need for MRI in the diagnosis of soft tissue sarcoma.