Leiomyosarcomas are “soft tissue sarcomas”. They are malignant tumours that form in the cells of smooth muscles controlled by the autonomic nervous system, mainly the uterus and the digestive tract, but also the dermis. There are very rare leiomyosarcomas that develop in the kidney, bladder, the inferior vena cava and the heart. This cancer affects women more than men, usually in their fifties and sixties. 

Leukaemias are cancers that originate in the bone marrow, in the blood stem cells that can transform themselves into different types of blood cells, such as red blood cells (erythrocytes), platelets and white blood cells (lymphocytes and myelocytes). If the blood stem cells become malignant, still immature abnormal white blood cells (leukoblasts) start to proliferate.

In parallel, insufficient production of red blood cells, healthy white blood cells and platelets occurs. Cancer cells can migrate from the bone marrow and reach the blood circulation and organs such as the spleen or the lymph glands. Leukaemias are classed according to the type of abnormal white blood cell (myeloid or lymphoid) and the progression of the disease (acute or chronic).

Liposarcomas are the most frequent form of the family of soft tissue sarcomas, rare cancers. These tumours derive from stem cells that have differentiated into fat cells (or adipocytes). The areas most often affected are the tissues of the lower limbs, especially the thighs, which make up more than 50% of cases, and the retroperitoneum located inside the abdomen. It can also affect the neck, torso and the extremities of the body.  

The lymphatic system comprises:

• the vessels that convey lymph, a clear liquid containing white blood cells, throughout the body; 
• the lymphatic organs (the bone marrow, which produces the white blood cells, the spleen, the thymus, the ganglia, etc.). 

The lymphatic system drains the tissues and transports the lipids resulting from food. It also plays a crucial role in the body’s immune system. 
 
The lymphatic vessels pass through numerous ganglia (groin, armpits, neck, abdomen and thorax). The mission of these small organs is to trigger an immune response and act as a filter: they eliminate waste and infectious agents present in the lymph before it enters the blood circulation.

Lymphocytes are a variety of white blood cell present in the blood and lymph tissue (lymph glands, spleen, thymus) involved in the body’s immune system.

• T lymphocytes combat cells infected by viruses and bacteria, foreign cells and cancer cells.
• B lymphocytes are specialised in producing antibodies.

The proportion of lymphocytes in the blood increases in the case of infection, and lowers for certain cancers and following chemotherapy. The malignant proliferation of lymphocytes is the cause of lymphomas and lymphocytic leukaemia.

A lymphoma is a cancer of the lymphatic system that affects the white blood cells (lymphocytes), the main cells of the immune system. Abnormal lymphocytes proliferate in what is known as lymphoid tissue: ganglia, spleen, bone marrow and thymus, as well as other organs.

There is Hodgkin’s lymphoma, which is quite rare, and non-Hodgkin lymphomas which are five times more common (11,000 new cases a year in France). Hodgkin’s lymphoma more usually affects young adults and is characterised by the presence of specific malignant cells known as Reed-Sternberg cells. Non-Hodgkin lymphomas concern people of all ages. They are classified as a function of their speed of evolution (from “indolent” to “aggressive”) and comprise a large number of sub-types. Substantial advances have been made in the treatment of lymphomas since the development of targeted therapies (anti-CD-20 monoclonal antibodies, protein kinase inhibitors, etc.), and bone marrow and stem cell transplants.

For further information: 
Targeted therapy: interview with Prof. Gilles Salles