The subcutaneous tissue is expanded and replaced by a lobulated tumour for the most part homogeneous, but showing areas of necrosis. At one point near the upper pole there is an area of aponeurosis and the tumour is extending through this as it is also infiltrating the dermis producing distortion of the skin surface.
This woman presented at the age of 72 with a 9-10 year history of a lump over the left olecranon which was regarded as gout. There was a similar lump on the antero-lateral aspect of the left shin which measured 10 x 8 cm. This was partially excised and proved to be a leiomyosarcoma. She had a previous history of rheumatoid arthritis. She refused amputation but ultimately the lesion began to bleed and the bleeding could not be controlled. The amputated limb showed a rheumatoid nodule on the heel. This leiomyosarcoma was centred in the subcutaneous plane and invading and ulcerating skin and extending into the anterior part of the tibia.