Malignant histiocytosis (which is a leukaemia-like disease of histiocytes) presents with a sudden onset of generalised symptoms such as fever, sweats, weight loss and enlarged lymph glands and enlarged liver and spleen. Other cells in the blood may decrease resulting in anaemia, low platelets (cells involved in clotting of the blood) and low white cells (infection-fighting cells). This condition is diagnosed by blood tests, tests on bone marrow (bone marrow aspirate) and tissue biopsies.

Leon had several blood tests from August, 2006, but it wasn't until he returned to see his G.P. on 2nd April, 2007, for more blood test results that abnormalities were detected and he was admitted to Northampton General Hospital (the day before his 22nd birthday). Leon was transferred to John Radcliffe Hospital in Oxford on 8th April, 2007, and diagnosed with Malignant Histiocytosis on Friday 13th April, 2007.

Malignant histiocytosis is an extremely rare cancerous condition in which there is uncontrolled proliferation of the histiocyte cell. Normal histiocyte cells are a type of white blood cell called macrophages which form part of the immune system, alerting infection-fighting cells to the presence of foreign material such as bacteria (antigen presentation). They also perform a waste-disposal function, getting rid of waste-products in the tissues (phagocytosis). Normal histiocyte cells are originally formed within the bone marrow and then migrate throughout the body via the bloodstream. Most forms of histiocytosis are rare. Malignant histiocytosis is the more aggressive form which progresses very quickly and treatment must be started as early as possible. Some people will not respond to treatment and some people will die before the condition can be diagnosed and treated.

Most types of cancer have 4 stages. Often doctors write the stage down in roman numerals. So you may see stage 4 written down as stage IV. When Leon asked what stage his cancer was, he was told stage 4 which is the most advanced. Here is a brief summary of what the stages mean for most types of cancer:

• Stage 1 usually means a cancer is relatively small and contained within the organ it started in.

• Stage 2 usually means the cancer has not started to spread into surrounding tissue, but the tumour is larger than in stage 1. Sometimes stage 2 means that cancer cells have spread into lymph nodes close to the tumour.

• Stage 3 usually means the cancer is larger. It may have started to spread into surrounding tissues and there are cancer cells in the lymph nodes in the area.

• Stage 4 means the cancer has spread from where it started to another body organ – this is also called secondary or metastatic cancer.

Treatment with chemotherapy has been used with some success but because of the rapid progression of this aggressive disease, the prognosis is very poor. Leon endured both CHOP (given 13th April, 2007) and ICE (given 27th April, 2007) chemotherapy.

CHOP is the name of a chemotherapy treatment which is:

• C = Cyclophoshamide

• H = Doxorubicin Hydrochloride (Adriamycin)

• O = Vincristine (also called Oncovin)

• P = Prednisolone

ICE is the name of a chemotherapy treatment which is:

• I = Ifosfamide

• C = Carboplatin

• E = Etoposide

As Malignant Histiocytosis is such a rare condition, there were very few cases worldwide that could be referred to and nobody had the same strain as Leon. Because it is so rare, information on this disease is limited and, in my continued attempt to find out as much about it as I can and try and understand what Leon went through, his consultant, Chris Hatton, summed it up in an email to my Mum: “In my experience the best way for relatives and patients to understand these conditions is to reduce them to their simplest fundamentals. Leon had an aggressive cancer that did not respond to chemotherapy. The cancer caused Leon's important organs to fail and he became very weak.” Leon is the bravest person I have ever known. I love him and miss him so much.