Primary cervical amyloidoma: a case report and review of the literature

Background context: Primary solitary amyloidosis or amyloidoma is a disease process characterized by the focal deposition of amyloid in the absence of a plasma cell dyscrasia with normal serum protein measurements. Solitary amyloidomas affecting the vertebrae are very uncommon but typically affect the thoracic spine. Primary cervical amyloidosis is an exceedingly rare entity with exceptionally good prognosis, but requires diligence of the treating physician to establish the diagnosis and implement the appropriate surgical intervention.

Purpose: This study aimed to present a rare case of primary cervical amyloidosis with long-term follow-up and review the clinical presentation, characteristic imaging findings, diagnostic pathology, differential diagnosis, treatment algorithm, and prognosis of the disease entity. This case demonstrates the progressive resorption of the amyloidoma over time after surgical stabilization. Previous reported cases of primary cervical amyloidosis will also be reviewed.

Study design: This study is a report and review of the literature.

Methods: A 77-year-old woman presented with a several-week history of gradual progressive weakness in her upper and lower extremities. Computed tomography and magnetic resonance imaging demonstrated a retro-odontoid nonenhancing soft-tissue mass, with erosive bony changes and severe mass effect on the upper cervical cord. The patient was taken to the operating room for decompression and posterior spinal stabilization.

Results: Intraoperative tissue specimens demonstrated amyloidosis and extensive systemic workup did not reveal any inflammatory processes, systemic amyloidosis, or plasma cell dyscrasia. Postoperatively, the patient regained full strength and ambulatory status. The patient remains asymptomatic at a 2-year follow-up. A postoperative follow-up magnetic resonance imaging demonstrated complete resorption of the residual amyloidoma.

Conclusions: Primary solitary amyloidosis is a rare form of amyloidosis that is important to differentiate given its excellent prognosis with surgical management. Treatment should include surgical decompression and spinal stabilization. This is the first case report to clinically and radiographically demonstrate the progressive resorption of a primary amyloidoma over time after surgical stabilization in the upper cervical spine. It is imperative that surgeons encountering such lesions maintain a high suspicion for this rare disease entity and advise their pathologists accordingly to establish the correct diagnosis.