Liposarcoma - a malignant neoplasm , belongs to the group of mesenchymal tumors , the cells of which tend to turn into fat. In frequency, they occupy the 2nd place (after fibrosarcoma ) among malignant tumors of soft tissues. These tumors are rare in children; the frequency of their occurrence increases with age, reaching the highest level in people 50-60 years old. Liposarcomas are more often observed in men. They can affect any part of the body, but nevertheless they are more often observed on the lower extremities, especially on the thigh and in the area of ββthe knee joint , as well as in the retroperitoneal space. The second most frequent site of localization of these tumors is the shoulder. Extremely rare (isolated cases) is the development of liposarcomas from both single and multiple lipomas [1] .
| Liposarcoma | |
|---|---|
 Micrograph of myxomatous liposarcoma. Stained with hematoxylin and eosin. | |
| ICD-O | M 8850/3 |
| Diseasesdb | 31482 |
| eMedicine | / 856 |
| Mesh | D008080 |
Content
Pathological Anatomy
Depending on the histological features, the following types of liposarcomas are distinguished [2] :
- highly differentiated liposarcoma
- low malignancy
- more than 50% of all liposarcomas
- contains a significant amount of adipose tissue, a synonym for atypical lipoma
- myxoid liposarcoma (embryonic lipoma);
- 2nd in frequency
- squamous liposarcoma / dedifferentiated liposarcoma;
- pleomorphic liposarcoma;
- mixed form
- may contain structures typical of all types of liposarcoma.
Etiology
Clinic and Diagnostics
Typically, liposarcomas develop deep in the tissues and are associated with intermuscular fascial and periarticular tissues. The clinical picture also depends on the degree of tumor differentiation [1] .
Clinically distinguish the following types of liposarcomas:
- highly differentiated liposarcoma (synonyms: polymorphonuclear lipoma, polymorphonuclear fibroadenoma, sclerosing lipoma);
- myxomatous liposarcoma (synonyms: embryonic lipoma);
- round cell liposarcoma (synonyms: adenoid lipoma, lipoma infiltrative-fetal cell, lipoblastic sarcoma);
- polymorphic liposarcoma (synonyms: true liposarcoma, lipocytic sarcoma);
- undifferentiated liposarcoma.
A rare option is mixed-type liposarcomas - a combination of myxoid or squamous with highly differentiated and pleomorphic components [3] .
Highly differentiated tumors grow slowly, bother the patient a little and are usually an accidental find when the tumor reaches a significant size.
Low-differentiated tumors (myxomatous liposarcoma) grow quickly and reach large sizes in a short period of time [1] .
Undifferentiated liposarcoma contains two separate components that are well differentiated from each other, namely, areas of well-differentiated liposarcoma and areas of high malignancy sarcoma , resembling either malignant fibrous histiocytoma or pleomorphic fibrosarcoma. These two components can be observed in different areas of the tumor at the same time, however, the second component can develop against the background of the first as the tumor progresses. The biological properties of this form of liposarcoma are not completely determined, but perhaps they partially depend on the severity of dedifferentiation [4] .
Liposarcomas can be multiple and occur in various areas of the body, however, it has been observed that retroperitoneal fiber is a favorite localization of highly differentiated liposarcoma; myxomatous liposarcoma - intermuscular adipose tissue of the thigh and lower leg. Liposarcomas mostly grow slowly and rarely metastasize; cases of the introduction of metastases along with blood flow to the lungs , liver , and bone marrow with myxomatous and polymorphic types of liposarcoma have been described [5] .
Diagnostics
On examination and palpation - it is soft, round, lobed, painless, a tumor delimited from adjacent tissues, covered with unchanged skin. Primary liposarcomas grow expansively, creating a false impression of their isolation and even encapsulation. In fact, they grow along intermuscular spaces [1] .
Differential diagnosis should be carried out mainly with lipoma , hibernoma and rhabdomyoma [1] . Single vacuole cricoid lipoblasts are similar to cells found in adenocarcinoma [6] .
Treatment
The main treatment for liposarcomas is the surgical removal of the tumor. The choice of surgical intervention method depends on the location, degree of malignancy of the tumor, its mobility, primary or recurrent nature, as well as the presence of metastases [1] . So, for example, intramuscular liposarcoma should be removed with a group of corresponding muscles . With multifocal, poorly delimited and spreading through the intramuscular or fascial spaces of the tumor , as well as in case of invasion of the bone, amputation of the limb is indicated. [6]
Postoperative radiotherapy (from 40 to 70 Gy) is indicated, especially in case of poorly differentiated and recurrent tumors [1] , as well as distant metastases.
Chemotherapy (doxorubicin, cyclophosphamide, vincristine, dactinomycin, bleomycin, dacarbazine) is used for large inoperable tumors, tumors with a high degree of malignancy or in the presence of metastases, it is often performed in combination with surgical treatment and radiation therapy [6] . In some cases (poorly differentiated liposarcomas) it is necessary to perform a radical operation [1] .
Forecast
It depends on many factors, but the degree of tumor differentiation is crucial (the higher the differentiation, the better the prognosis). So, relapses occur in 36.4% of cases, metastases 31.8%, the overall 5-year survival rate is 58.9% after complex treatment [7] . A persistent recovery (100%), according to various sources, is achieved in 30-40% of cases [1] .
Literature
- Oncology - a textbook for honey. in-to / B.E. Peterson. - M.: Medicine, 1980 .-- 447 p. : ill. - 01.20 p.
- Handbook of Oncology / edited by prof. B.E. Peterson. - Tashkent: Medicine, 1966. - 500 p.
Links
Notes
- β 1 2 3 4 5 6 7 8 9 Handbook of Oncology / edited by prof. B.E. Peterson. - Tashkent: Medicine, 1966. - 500 p.
- β Vinay Kumar, Abul K. Abbas, Nelson Fausto. Pathologic basis of disease. - Elsevier Saunders, 2005.
- β Liposarcoma of limbs in adults. Per. from English N. D. Firsova (2017)
- β Oncology. Sarcoma. Liposarcoma | www.radiomed.ru - site for doctors of radiation diagnostics . Date of treatment October 26, 2012. Archived April 19, 2013.
- β Liposarcoma . Date of treatment September 27, 2016. Archived on April 19, 2013.
- β 1 2 3 http://meduniver.com/Medical/Dermat/322.html MedUniver
- β Liposarcoma . Date of treatment April 12, 2013. Archived April 19, 2013.
See also
- Lipoma
- Malignant tumors