Amyloidoma of the temporal bone and upper cervical spine; presentation of a rare clinical entity with a brief literature review

The amyloidoses comprise a heterogeneous group of diseases characterized by the extracellular deposition of an insoluble protein complex in various tissues. Amyloidomas in bone are most common in patients with systemic amyloidosis and plasma cell dyscrasias. Decreased clearance of beta2 microglobulin frequently causes excessive amyloid deposition in the musculoskeletal system in patients with a history of chronic renal failure and long-term dialysis treatment. Calvarial and/or upper cervical amyloid depositions are rarely seen in clinical practice; therefore the diagnosis requires high index of suspicion and special staining of the tissue. In this article, we present a patient with amyloidoma at the right temporal bone and upper cervical spine. The etiology, radiological findings and differential diagnosis were briefly discussed in the highlights of relevant literature. Amyloidomas should be particularly kept in mind in patients with a history of long-term dialysis therapy, plasma cell dyscrasias or long-standing inflammatory diseases. Differential diagnosis mostly encounters benign or malign mesenchymal neoplasms of the dura and skull base, metastatic tumors, plasmacytoma and brown tumor in the calvarium, as well as primary osseous tumors or metastatic lesions in the spine.