Imaging of focal amyloid depositions in the head, neck, and spine: amyloidoma

Abstract

Amyloidomas are benign tumorlike lesions consisting of localized deposits of amyloid and are the rarest form in the group of amyloidosis-related lesions. Diagnosis requires special stains; therefore, a high degree of suspicion for this disease is required. In this review, we describe the imaging features of amyloidomas involving the intracranial compartment, head and neck, and spine. We also discuss the differential diagnosis and briefly review the pertinent literature.

Fig 1.

Intracranial amyloidoma in a 54-year-old woman with 2 episodes of left-hemispheric seizures. Axial CT scan of the head without contrast (A), axial T2-weighted image (B), axial T1-weighted image precontrast (C), axial postcontrast T1-weighted image (D), and a histopathologic section stained with Congo red (E). CT (A) shows a hyperattenuated mass in the deep white matter with medial extension up to the lateral ventricular ependyma. On MR imaging (B−D), the mass is iso- to hypointense on T1WI and T2WI and reveals marked enhancement on postgadolinium T1WI. D, Note the fine radiating lines at the medial aspect of the tumor (arrow), which are thought to be due to deposition of amyloid along the blood vessels, a finding frequently observed on histopathology. E, Courtesy of Mila Blaivas, University of Michigan, Ann Arbor, Michigan (Congo red, original magnification ×100).

Fig 2.

Clival amyloidoma in a 45-year-old woman with left facial numbness and pain for 1–2 months. MR imaging of the skull base shows a mass involving the left clivus. The mass (arrows) is hypointense on T2WI (A) and shows homogeneous enhancement with contrast (B).

Fig 3.

Laryngeal amyloidoma in a 27-year-old man with long-standing juvenile rheumatoid arthritis and progressive hoarseness. Sagittal T1-weighted image (A), axial T2-weighted image (B), axial T1-weighted image (C), and axial postcontrast with fat-saturation T1-weighted image (D) demonstrate a 15-mm left supraglottic submucosal mass (arrows), which is isointense to muscle on T1 and enhances homogeneously with contrast. This lesion has notable decreased signal intensity on the T2WI, suggestive of an orderly matrix with little free water. The lesion was pathologically proved to be amyloidoma. The patient did not have any evidence of systemic disease. Courtesy of Steve Gebarski, University of Michigan, Ann Arbor, Michigan.

Fig 4.

Orbital amyloidoma in a 32-year old woman with a slowly increasing mass in the right orbit and generalized bone pain. A, CT scan of the orbits shows a large mass involving the right superolateral orbit. B, The sclerotic/calcified mass involves the right frontal bone and the right lacrimal gland.

Fig 5.

Thoracolumbar spine amyloidosis in a 54-year-old woman with back pain for a few-months' duration. Coronal and sagittal reformatted CT scan of the thoracolumbar junction reveals an irregular soft-tissue mass at the superior endplate, causing mild underlying sclerosis. The patient was initially treated for infection, but because there was no response, it prompted biopsy and amyloidosis was found.

Fig 6.

Thoracic spine amyloidoma in a 45-year-old woman with progressive back pain and lower limb paraparesis. A, Prone-oblique lumbar myelogram reveals an extradural mass at the level of the L4 vertebral body posterolateral to the thecal sac (arrows). B, CT myelogram at the same level shows a mass (arrows) in the ligamentum flavum, which was initially thought to be a synovial cyst. This turned out to be amyloidoma of ligamentum flavum. There was no evidence of systemic amyloidosis or plasma cell dyscrasia.

Fig 7.

Pelvic bone involvement in a 62-year-old man with chronic low back pain radiating to the right lower extremity. Axial CT scan of the pelvis (A) and shaded-surface display (B) show a large destructive mass with exuberant calcifications involving the right ilium and sacrum (arrows) in a patient with multiple myeloma. Note the extension of the tumor into the sacral neural foramen on the right side. Multiple biopsies failed to demonstrate any plasma cells in this mass. Pathologic diagnosis was consistent with an amyloidoma.

Fig 8.

Spinal MR imaging in a 44-year-old woman with progressive numbness and weakness of all 4 extremities and mild autonomic dysfunction. Sagittal and axial postcontrast-enhanced T1-weighted image shows extensive pial enhancement, completely coating the surface of the cervical and thoracic cord (arrows). Amyloid deposits were found at biopsy.