Leiomyosarcoma
| Classification according to ICD-10 | |
|---|---|
| C49.- | Leiomyosarcoma |
| ICD-10 online (WHO version 2019) | |
The leiomyosarcoma ( Greek lī'ō, leio- , 'smooth, gentle' and μυς, mys 'muscle', σάρκωμα, sárkoma, to σάρξ, sárx "flesh", "soft tissue" and -om "tumor") is a malignant one ( Malignant ) tumor that originates from the smooth muscles . Among other things, it accounts for about 1% of all malignant uterine tumors. This tumor usually occurs after the age of 30 and has its age peak in the 6th decade of life. The symptoms are mostly unspecific; if localized in the uterus, the uterus rapidly enlarges with bleeding. Leiomyosarcomas can also be found on the smooth muscle anywhere else, e.g. B. also from the hair follicle muscles , and thus occur in principle on the entire body surface.
pathology
During embryonic development , the so-called mesoderm develops, among other things, into the musculoskeletal system (bones, muscles), the soft tissues and the blood and lymphatic system. When fully developed, these types of tissue are referred to as mesenchymal tissues . Almost all malignant tumors that arise from such mesenchymal tissues are called sarcomas . The leiomyosarcoma metastasize primarily via the bloodstream.
While it was previously suggested that the leiomyosarcoma can degenerate from a benign leiomyoma, current studies show that this is unlikely. There is also no evidence that previous radiation exposure is a risk factor.
Leiomyosarcomas rarely occur in the context of a hereditary retinoblastoma , and changes in the RB tumor suppressor gene are also found in a few tumors .
diagnosis
Due to the unspecific symptoms, the diagnosis is usually an incidental finding if an operation was necessary for other reasons.
The leiomyosarcoma cannot normally be distinguished from the leiomyoma in the surgical specimen; any necrosis that may occur can provide an indication of the dignity . Furthermore, infiltrations into the surrounding tissue such. B. if localized in the uterus in the myometrium , endometrium or parametrium suspicious for malignancy.
In the histology is multiform find nuclei and giant cells . The most relevant criterion for the diagnosis of leiomyosarcoma remains the abundance of mitosis (more than 10 mitoses in 10 fields of view at 400x magnification) and the simultaneous diversity of the cells ( cell polymorphism ).
therapy
Since leiomyosarcoma does not respond adequately to chemotherapy and radiation therapy, surgery is the focus of therapy. There are currently no binding standards, as leiomyosarcoma on the one hand belongs to the heterogeneous group of sarcomas and on the other hand its occurrence is very rare.
In around 30% of cases, metastases are found in the ovaries if they are located in the uterus , so removal of the ovaries at the same time is advisable ( ovariohysterectomy ). In 3 to 5% of diagnosed leiomyosarcomas there are also metastases in the large network (greater omentum) . Affected lymph nodes are found in the pelvis and next to the main artery in 4 to 35% of those affected . However, removing these lymph nodes does not seem to prolong life. The leiomyosarcoma leads to a recurrence of the malignant tumor in 50 to 70% of cases, usually within the first two years. It metastasizes mainly in the lungs and has a poor prognosis.
Only the low-grade leiomyosarcomas, which belong to the less dangerous types, have a better survival rate. They progress slowly, so that tumors usually only reappear after 10 years. The affected patients have a long life expectancy. Overall, a 5-year survival rate of 50% is assumed.
swell
- U.N. Riede: General and special pathology. 3., rework. Edition. Thieme, Stuttgart / New York, ISBN 3-13-683303-1 .
- SL Robbins: Robbins basic pathology. 8th edition. Elsevier Saunders, Philadelphia 2007, ISBN 978-1-4160-2973-1 .
