Collapse in a 79-year-old: a rare case of amyloid tumour of the pelvis.

A 79-year-old man presented to accident and emergency with collapse, unable to bear weight on his left leg. Computed tomography revealed a large isolated lesion (28 x 12 x 8 cm) extending from the pelvis into the abdomen, affecting the left lumbrosacral nerves. Further investigations showed that the mass contained amyloid protein. With no evidence of systemic amyloidosis or malignancy a diagnosis of amyloidoma/amyloid tumour was made. This is the largest amyloid tumour reported in the literature to date. There is limited but conflicting evidence regarding the pathophysiology, management and prognosis of amyloidoma. Clearly amyloidomas are rare, but patients can present acutely and may have a poor prognosis, especially when the tumour is of considerable size.