Sarcoma & Retroperitoneal Tumours

Sarcomas are rare cancers that arise from connective tissues such as fat, muscle and fibrous tissue. The retroperitoneum, the space at the back of the abdomen, can harbour large tumours that grow silently for a long time. Because these tumours are uncommon and complex, the first operation matters greatly, and treatment should be planned by an experienced multidisciplinary sarcoma team.

Retroperitoneal liposarcoma

What it is: The most common sarcoma of the retroperitoneum, arising from fat cells. Well-differentiated forms grow slowly, while dedifferentiated forms behave more aggressively.

Symptoms: Often none until the tumour is large; abdominal swelling, a feeling of fullness, back pain or leg swelling may occur.

Treatment: Complete surgical removal, often together with adjacent organs, is the main treatment. Radiotherapy or chemotherapy may be added in selected cases.

Leiomyosarcoma

What it is: A sarcoma arising from smooth muscle, which in the abdomen may originate from the wall of large veins such as the inferior vena cava, or from other organs.

Symptoms: Abdominal pain or mass, leg swelling, or symptoms related to the organs involved.

Treatment: Surgical resection with clear margins, sometimes including vascular reconstruction, combined with chemotherapy according to risk.

Soft tissue sarcoma of the trunk and abdominal wall

What it is: Malignant tumours of connective tissues arising in the muscles or deep tissues of the trunk and abdominal wall.

Symptoms: A growing lump, especially one larger than 5 cm, deep to the muscle layer or increasing in size, whether painful or not.

Treatment: Biopsy before surgery, followed by wide surgical excision with reconstruction when needed, and radiotherapy in selected cases.

Desmoid tumour

What it is: A locally aggressive tumour that does not spread to other organs but can grow into surrounding tissues. It may occur in the abdominal wall, the mesentery or elsewhere.

Symptoms: A firm mass, sometimes painful; intra-abdominal desmoids may cause bowel obstruction.

Treatment: Active surveillance is often the first step, as many stabilise or shrink. Medical treatment, and surgery in selected cases, are used for progressive or symptomatic tumours.

Benign retroperitoneal tumours

What it is: Non-cancerous masses such as schwannomas, paragangliomas, lipomas and cystic lesions, which can be difficult to distinguish from sarcoma without specialist imaging.

Symptoms: Often found incidentally; larger lesions can cause pressure symptoms.

Treatment: Accurate diagnosis with CT or MRI and, when appropriate, biopsy. Surgery is recommended for symptomatic, growing or uncertain lesions.

How assessment is organized

Assessment includes CT of the chest, abdomen and pelvis and often MRI, with an image-guided core biopsy when needed before any surgery. Treatment is planned within a multidisciplinary sarcoma team including surgeons, radiologists, pathologists and oncologists.

This information is general and does not replace individual medical assessment.