By Professor Gilles Grateau – Tenon Hospital PARIS – FRANCE
What is localised amyloidosis?
Most forms of amyloidosis are characterised by damage to several tissues and organs and are known as systematic or, better, multi-systematic forms. Nonetheless, some forms of amyloidosis affect only one organ.
They are nearly always cases of AL (or immunoglobulin related) amyloidosis. The amyloidosis deposit formed of light chains of antibodies is made in contact with a proliferation of plasma cells located in a specific organ. No light chain of immunoglobin enters the blood stream and consequently the deposits are not constituted in other organs.
How is a localised amyloidosis diagnosed?
These are very rare diseases and their diagnosis is hardly ever evoked by physicians who think first of a more common disease, particularly the presence of a tumour.
The symptoms of these kinds of amyloidosis are directly linked to the affected organs
- Dysphonia with a gradual modification of the voice, coughing, breathlessness in the case of the upper airways (trachea, bronchial tubes).
- Presence of blood in the urine, urination disorders, lower abdominal pain in the case of urinary amyloidosis.
As with all forms of amyloidosis, their diagnosis is based on a biopsy of the affected organs. Therefore, it is a specialist in pathological anatomy who discovers in the biopsies that there is no tumor but rather amyloid deposits. These deposits are rarely characterised precisely in immunohistochemistry, a technique which can determine what kind of amyloidosis is present. It is essential to be able to assert the local nature of the lesions and to be sure that there is no amyloidosis in the other organs. This question can best be answered by a clinical examination and simple additional tests.
Evolution and treatment
Evolution is very variable and requires local monitoring by a specialist for the organ which has been affected, for example an otolaryngologist in the case of amyloidosis of the larynx, and general check-ups to ensure that the amyloidosis remains localised.
Treatment is discussed on a case-by-case basis according to the effect of the amyloidosis on the functions of the affected organ. Surgery may be prescribed to remove some of the deposits. For certain lesions radiotherapy may be used. Systemic medication is rarely prescribed. In certain forms of amyloidosis of the bladder, local medical treatment can be used.