A man with multiple skin tumors and a thigh mass

Case Identification

Case ID Number
Benign or Malignant

Clinical case information

Case presentation

This man has multiple skin lesions as shown. A large, deep, painless, progressively growing soft mass is present in the left posterior thigh. Sensation is normal in the left leg and foot. What is the likely diagnosis? Given the diagnosis you suspect, what treatment is required?

Radiological findings:
A T1 dark and T2 variegated mass is seen in the left posterior compartment of the thigh, approximately 10 x 15 cm. Note the relationship to the neurovascular elements.
Differential Diagnosis
Soft tissue sarcoma, other mesenchymal neoplasm.
Further Work Up Needed:
Biopsy pending
Treatment Options:
This lesion will require removal. Outline your recommended surgical treatment given three scenarios: 1) The lesion is benign 2) The lesion is a low grade sarcoma 3) The lesion is a high grade sarcoma.
Special Features of this Case:
This is a real case but the details have been left out to increase the teaching value of the case and challenge the reader. The association of the skin lesions and the mass in the thigh - discuss.