Fibro-osseous pseudotumor in the neck: Report of a case and literature review

Abstract

Objectives: We present a case of fibro-osseous pseudotumor in an adolescent male with a 1-month history of a right posterior neck mass. We present the differential diagnosis, radiographic, clinical, surgical, and pathologic aspects, and a review of the medical literature for this rare and unusual fibro-osseous pseudotumor presenting in this location. Methods: Fibro-osseous pseudotumor is reported to occur in the digits, toes, and neural axis, falling under a diagnosis of myositis ossificans. This patient presented with a large fibro-osseous pseudotumor in the neck that has not been identified in the medical literature. Results: Fibro-osseous pseudotumor is a benign soft tissue lesion that usually affects the digits but has also been known to occur in the neural axis. Fine needle aspiration was nondiagnostic and magnetic resonance imaging showed a large mass posterior to the carotid sheath and deep to the trapezius and splenius capitis muscles. Excisional biopsy demonstrated fibro-osseous pseudotumor. Conclusion: Fibro-osseous pseudotumor is benign, soft tissue growth that has not been previously reported in the neck. These tumors present as a poorly defined soft tissue mass with calcification or focal periosteal thickening but do not involve adjacent bone. This poster demonstrates a well-defined mass in a new location for fibro-osseous pseudotumor. It includes the differential diagnosis, radiographic, clinical, surgical, and pathologic aspects of this disease and a review the medical literature.