Tendinous xanthomas occur as free mobile papules or nodules in the tendons, ligaments, fascia and periosteum especially on the backs of the hands, fingers, elbows, knees and heels.
Click here for an example image of tendon xanthomata
- tendon xanthomata are diagnostic hallmarks of familial hypercholesterolaemia - other causes of tendon xanthomata are so very rare (phytosterolaemia and cerebrotendinous xanthomata) that the presence of raised cholesterol and tendon xanthomata is virtually diagnostic of famial hypercholesterolaemia
- other hyperlipidaemic causes associated with tendon xanthoma include:
- drug-induced hyperlipidaemia (antiretroviral therapy) or familial recessive hypercholesterolaemia both may develop tendon xanthomas
- occasionally tendon xanthomas may occur in normolipidaemic patients
- cerebrotendinous xanthomatosis is an autosomal recessive lipid storage disease where patients are typically normolipidaemic but they have elevated blood cholestanol and prominent xanthomas in tendons and the brain
- hyper-b-sitosterolaemia is a disease with elevated plasma cholestanol and lipid storage in tendons
- Achilles tendons are the most common sites of tendon xanthomas
- low-density lipoprotein (LDL) derived from the circulation accumulates into tendons
- there is then a transformation of LDL into oxidized LDL (oxLDL) and the active uptake of oxLDL by macrophages within the tendons
- Achilles tendon xanthomas may be detected on clinical examination
- also may be diagnosed via ultrasound
Reference:
- Tsouli SG et al. Pathogenesis, detection and treatment of Achilles tendon xanthomas. Eur J Clini Invest. 2005 Apr;35(4):236-44. doi: 10.1111/j.1365-2362.2005.01484.