Wild-type Transthyretin Amyloidosis Occurring in the Ligamentum Flavum of the Cervicothoracic Spine.

Abstract Background Wild-type transthyretin amyloid (ATTRwt) has been noted to deposit in the ligamentum flavum of the spine. Prior studies have focused on ATTRwt in the lumbar region, but there is a lack of studies discussing its presentation in other levels of the spine. We report on the presentation of patients with confirmed amyloid in the cervicothoracic regions, and discuss the literature to date. Methods We retrospectively identified patients at a single institution that underwent surgery for spinal stenosis and had pathologic specimens sent for amyloidosis testing with Congo Red staining. ATTRwt was confirmed by the presence of ATTR by typing and the absence of mutations in the TTR gene sequence. A final study of ATTRwt patients with spinal involvement was made (n=27). Results Of the 27 patients with amyloid in the spine, 24 (8 9%) had amyloid present in the lumbar region, while 2 (7%) had it present in the cervical region and 1 (4%) had it present in the thoracic region. The median age at which patients in the study underwent surgery was 71 years (IQR: 9). 26 of 27 (96%) patients had spinal stenosis as the indication for surgery. 24 of 27 (89%) patients had surgery that involved 1 to 2 spinal levels. Conclusions ATTRwt amyloid predominantly deposits in the lumbar region, but it can also be present in the cervical and thoracic regions as well. While the lumbar regions should remain a focus for evaluation of ATTRwt amyloidosis, the cervicothoracic region should not be ignored.