Soft tissue tumors are derived embryologically (embryology: development of the fertilized egg and the resulting embryo) from a specific tissue of origin, the so-called mesoderm. This in turn forms the supporting and filling tissue, the musculoskeletal system and the smooth muscles of the hollow organs. This means that soft tissue tumors can occur almost anywhere in the body, where they can be either benign, slightly malignant or very malignant.

The benign variants include fat (e.g. lipomas, angiomyolipomas), cartilage (e.g. chondromas) and other tissues. There is a smooth transition to the less malignant forms such as liposarcomas and then to the various soft tissue tumors of higher malignancy. These tumors are very different in their histological appearance and clinical behavior and are referred to as sarcomas. A particular subtype of sarcoma, rhabdomyosarcoma, is common in early childhood. They grow around the bladder and the neighboring structures in the small pelvis. The so-called non-rhabdomyosarcomas, such as synovial sarcomas, infantile fibrosarcomas, etc. are more commonly observed on the arms and legs and around the trunk (neck, chest, abdomen, pelvis).

Unfortunately, these tumors are often discovered very late. They are initially conspicuous due to inconspicuous, often painless swellings in the abdomen/pelvic area or on the arms/legs.

The diagnosis is always made on the basis of a histological examination. The tissue specialist (pathologist) sees the staining of the typical "small blue cells" under the microscope, which he must then examine more closely using tissue markers and cell genetics. Rhabdomyosarcomas, for example, are roughly divided into embryonal, alveolar and pleomorphic subtypes, which all require different treatment and also differ in terms of their prognosis.

The treatment of childhood tumors has been a focus of the Clinical Department of Pediatric Surgery at the MHH since the 1980s. Then as now, we offer a high level of expertise in pediatric tumor surgery, as evidenced by our designation as a surgical reference center in treatment protocols of the GPOH (Society for Pediatric Oncology and Hematology)
The treatment of malignant diseases in children is always multidisciplinary and is based on the specifications of the respective therapy protocols. This naturally also applies to the treatment of soft tissue tumors. Every diagnostic and therapeutic measure follows the recommendations of the treatment study or, in special cases, the explicit recommendation of the study management of the Cooperative Soft Tissue Study (CWS).

If such a tumor is suspected, an initial ultrasound is usually followed by further imaging (magnetic resonance imaging ("MRI"), X-ray, computer tomography). In young children, these examinations are often performed under anesthesia, as "sharp" images can only be obtained when the children are lying very still without moving. In order to confirm the diagnosis, it is essential to take a tumor sample under general anesthesia. This is usually done via open surgery or a minimally invasive approach. Tissue punctures are the exception in order to avoid tumor cell spread along the canal.

 

 

Once the histological diagnosis has been made, the so-called environmental diagnostics with examination of the lungs and the rest of the skeleton are carried out. The treatment plan is drawn up together with our pediatric oncologists on the basis of the CWS study.

Further therapy is always based on the specifications of the CWS protocols, which provide a special treatment regimen for each type of tumor that cannot be described in detail here.

Most treatments follow a similar scheme: for drug therapy, a so-called port catheter (a permanent access to the venous blood circulation under the skin) or another central venous catheter (e.g. "Broviak catheter") is often implanted, whereby special systems are available for babies. We implant approx. 130 such systems per year.
The first cycles of chemotherapy are then started. If the tumor responds well to this treatment and becomes smaller, its surgical removal or reduction can be planned. This is usually followed by further follow-up treatment with cytostatic drugs. Tumors that have already metastasized can also be treated successfully under certain circumstances. In these cases, however, several surgical interventions are necessary.

The prognosis of such a tumor disease depends on numerous factors and cannot be universally defined. An assessment of the individual treatment success is made both at the beginning of the therapy and is adapted to the further course of the disease. This information can only be presented and discussed in a personal consultation. In any case, it is essential that children with oncological diseases are only treated in centers that are certified in every respect. The success of treatment for these diseases also depends on the experience of the departments involved and is highest where the most patients are treated. The MHH's pediatric medicine department has many years of successful experience in this field in cooperation with all the disciplines involved.

The operation is often followed by a further cycle of chemotherapy before the implanted port system can be removed again. Follow-up care is also carried out in accordance with the study protocols and is usually carried out by colleagues in pediatric oncology.