Resecting An Extensive Multi-Compartmental Tumor In The Lower Extremity

These authors present the diagnosis and treatment of a soft tissue mass in the leg of a 61-year-old patient.

A 61-year-old female received a referral to a different provider in July 2011 for evaluation of a right leg soft tissue mass. The patient perceived that the mass may be growing. Her medical history was negative for constitutional symptoms except for a heart murmur.

The exam and radiograms revealed a large mass of low density within the anterior and deep posterior compartments of the right leg. This suggested a lipoma. A subsequent computed tomography (CT) scan was suggestive of a lipoma as well. Previous primary care physicians completed the pre-surgical workup and originally scheduled the patient for surgical excision to be completed in July 2011. Her previous surgeons indefinitely cancelled her surgery for unknown reasons, perhaps due to her out-of-control diabetes and HbA1c of 12.3%. We have not been able to ascertain the exact reasons for the cancellation and indefinite postponement. Clinical notes express continued pain and difficulty controlling it given the patient’s allergies.

Her primary care provider referred her to the lead author, a general surgical oncologist. She subsequently presented on May 12, 2016 at the Northern Navajo Medical Center Department of Surgery Clinic. The surgeon reviewed punch biopsies taken by the previous provider. Questions arose as to the adequate depth of the obtained biopsy. Dr. D’Emilia obtained a complete history and performed a physical exam. There was some concern for possible sarcoma as the patient had a family history of colon cancer. The lead author performed additional core biopsies and ordered magnetic resonance imaging (MRI), an electrocardiogram (EKG) and an HIV screening.

There was some concern for possible malignancy. Worrisome features included an increase in size and pain, some extension weakness, and a questionable core biopsy diagnosis of lipoma.

Surgical concerns with excision were possible malignancy; multi-compartment involvement; interosseous ligament invasion; and injury to muscles and neurovascular structures. The CT and MRI studies revealed that the mass displaced the anterior tibial neurovascular structures and muscle significantly anterior within the muscle compartment. This left an excellent incision window at the anterolateral aspect. Surgeons planned a second incisional approach at the posterolateral leg. The neurovascular bundle of the posterior tibia artery, veins, nerve and all muscle groups that typically insert into that membrane/ligament were markedly displaced posteriorly by the mass.  

The local exam revealed the right lower extremity was negative for edema and there was no associated numbness. The patient had slight ankle flexion weakness of about 4/5 strength. Her pedal pulses were 2/4. The integument was warm and she had normal turgor and color. Our diagnostic impressions included an enlarging right calf mass, possible liposarcoma and possible lipoma.

What The Surgical Course Entailed

In regard to the surgical excision, we made one incision at the anterolateral aspect of the right leg and deepened the incision through the deep fascia. We bluntly dissected he mass from the anterior compartment of the leg, leaving the anterior leg muscles and neurovascular structures intact. The mass had traversed through the interosseous membrane through a defect in the membrane about 4 cm long to the width of the constraints of the tibia and fibula.

Using Metzenbaum scissors, we separated the interosseous membrane along most of its length and excised the remainder of the mass via en bloc blunt dissection from the deep muscle compartment. We were able to ensure full preservation of the muscles and neurovascular structures. We excised the entire mass through a single incision anterolateral to the right leg. After installing a Jackson-Pratt drain, we closed the skin in a traditional manner. There was no attempt to repair the incised interosseous ligament. Several days later, we removed the drain.

The patient made a full recovery with no sensory or functional impairment. All muscles retained function and full strength was present in the right leg. All pain in the right leg was resolved.

Dr. D'Emilia is a board-certified and fellowship-trained surgical oncologist who is in private practice in Shiprock, NM.

Dr. DuRussel is the Chief of Podiatry and the Acting Chief of Surgery at the Northern Navajo Medical Center in Farmington, NM.