What is sarcoma and where does it grow from?
Unlike carcinomas, which develop from the epithelium, sarcomas originate from tissues that form support and movement: muscles, fat, tendons, blood vessels, and nerves. There are several dozen histological types, and the growth rate, sensitivity to drug therapy and prognosis depend on the specific type. The tumor usually grows in the form of a node, pushing away the surrounding tissue and forming a false capsule; in fact, tumor cells extend beyond its boundaries, so it is impossible to simply remove the node along the border.
- Liposarcoma - from adipose tissue
- Leiomyosarcoma - from smooth muscle
- Undifferentiated pleomorphic sarcoma
- Synovial sarcoma - more common in young people
- Sarcomas of the retroperitoneum
- More than 50 histological variants
How to distinguish it from a regular lipoma
Lipoma is a benign fatty tumor: soft, mobile, grows very slowly, lies just under the skin and usually does not exceed a few centimeters. Sarcoma is often dense, located deeper, under the fascia or in the thickness of the muscle, moves to a limited extent and grows noticeably faster. Pain appears late, when the tumor presses on a nerve or vessel, so its absence does not prove anything. They can only be reliably distinguished by MRI and histological examination.
- Lipoma is soft, mobile, superficial
- Sarcoma is dense, deep, does not move well
- Size greater than 5 cm is a risk factor
- Rapid growth within months
- Absence of pain does not exclude tumor
- The final answer comes from a biopsy.
Symptoms
Tumors of the limbs and torso appear for a long time only externally - as a growing compaction without other complaints. When the node reaches a large size, there is a nagging pain, a feeling of fullness, numbness or weakness due to pressure on the nerve, and swelling below the level of the tumor. Retroperitoneal sarcomas are discovered late: they manage to grow to large sizes before causing a feeling of heaviness in the abdomen, early satiety, nausea, or disruption of the intestines and urinary tract.
- Painless growing lump
- Feeling of fullness and nagging pain
- Numbness and weakness in the limbs
- Swelling below the level of the tumor
- Heaviness in the abdomen with retroperitoneal localization
- Weight loss and weakness in a common process
Survey
The first step for a superficial formation is often an ultrasound, but the main method is an MRI with contrast: it shows the size, depth, relationship to vessels, nerves and bone. Then a trephine biopsy is performed with a thick needle, and the location and direction of the puncture are planned so that the canal can be removed during a future operation. To search for distant lesions, a CT scan of the chest is done, since sarcomas most often metastasize to the lungs. It is impossible to operate without preliminary diagnosis.
- Ultrasound of soft tissues as the first step
- MRI of the affected area with contrast
- Trephine biopsy with histology and immunohistochemistry
- CT chest
- CT or MRI of the abdomen for retroperitoneal localization
- Consultation at a specialized center before surgery
Treatment
The basis of treatment is surgery to remove the tumor en bloc along with the surrounding layer of healthy tissue. The modern approach allows in most cases to save the limb, and amputation is rarely considered. Radiation therapy is given before or after surgery to reduce the risk of the disease returning in the same location. Chemotherapy is not effective for all types and is used for high-grade malignancy or advanced disease. The tactics are determined by the consultation, and after treatment, regular monitoring is needed, including CT scan of the lungs.
- Wide en bloc tumor excision
- Radiation therapy before or after surgery
- Chemotherapy for certain types
- Organ-preserving tactics, reconstruction and prosthetics
- Rehabilitation and restoration of limb function
- Regular follow-up with chest CT scan
- Treatment in a specialized center
