Orthopedic Oncology cases soft-tissue sarcoma

A 78-year-old male is referred to your office by his general surgeon. Six years ago, he underwent surgery to remove a lipoma from his right upper back. The postoperative pathology report at that time showed pleomorphic liposarcoma, and he therefore received radiation to the area. Over the past 4 months, he has been noticing a slowly enlarging mass in the area of his prior surgery.

After history, physical examination, and review of shoulder x-rays, what is the next best step?

1. Ultrasound of the shoulder

2. MRI of the shoulder with/without gadolinium, CT of the chest, abdomen, and pelvis

3. CT of the shoulder and CT of the head

4. Preoperative lab testing

 

Discussion

The correct answer is (B). The patient likely has recurrence of his liposarcoma. The mass must be evaluated with gadolinium-enhanced MRI, and in anticipation of recurrent malignancy, he should be evaluated for metastases. Pleomorphic liposarcoma usually metastasizes to the lungs or potentially the retroperitoneum, therefore a CT scan should be ordered in conjunction with the MRI.

Imaging reveals a large 9 cm × 5 cm × 4 cm intramuscular mass in the infraspinatus, consistent with liposarcoma. His chest CT is within normal limits. What is the most important prognostic factor in the AJCC classification system?

1. Size (< or >8 cm)

2. Nodal involvement

3. Discontinuous tumor within the same compartment

4. Presence of metastases

 

Discussion

The correct answer is (D). The AJCC staging system for soft-tissue sarcomas is based on the grade of the tumor, its size and depth, regional lymph node involvement, and presents of metastases. All other factors become irrelevant when metastases are present; the lesion is classified as stage IV in this case. Prognosis is based on stage, therefore the presence of metastases is the most highly correlated

with overall prognosis.

 

What principle should be followed during your surgical treatment of his recurrent tumor?

1. The prior surgical scar and tract should be excised

2. The prior surgical scar and tract should be avoided

3. Incision is placed in the axillary fold, to reduce the visibility of the scar

4. A drain should be avoided

 

Discussion

The correct answer is (A). After an unplanned excision of a malignant tumor, you should assume that the tract used to gain access to the tumor and resect it is now contaminated with malignant cells. As part of your revision resection, the entire prior tract should be excised. Distant incisions are not used, regardless of cosmetics. Drains are often used in these cases to prevent hematoma formation. All drains should be placed in line with and close to the incision in the event the tract will need to be excised in the future.

 

Objectives: Did you learn...?

 

To recognize a liposarcoma?

 

 

Staging and workup of a soft-tissue sarcoma? Treatment of a soft-tissue sarcoma?