Focal fibrocartilaginous dysplasia in the thoracic vertebra: A case report

Abstract

Focal fibrocartilaginous dysplasia (FFCD) is a rare, paraneoplastic disease that often presents in children and teenagers. Previous studies have reported cases of lesions in the proximal tibia and distal femur, as well as lesions in the upper extremities. The present study describes a case of FFCD on the transverse process and the rib. The imaging findings were found to correspond with the typical observations of FFCD and a biopsy from the nidus revealed pathological results similar to those of previous reports. Thus, the present study demonstrated that FFCD affects tubular bones as well as flat bones. Further studies are required to investigate the underlying mechanism and treatment of FFCD.

Keywords: focal fibrocartilaginous dysplasia; rib; thoracic vertebra.

Figure 1

X-ray, computed tomography (CT) and magnetic resonance imaging (MRI) of the lesion. (A) X-ray revealing a lucent and inflated lesion in the left first transverse process and the costal head (black arrow). (B) Chest CT showing that the two sides of the lesion were sclerosing and that the cortical bone of the lesion was thinning, but intact. No signs of periosteal reaction or cortical destruction were observed. (C–E) MRI showing (C) a low signal of the lesion in the T1-weighted image, (D) an intermediate signal of the lesion in the T2-weighted images and (E) a high signal of the lesion in the fat suppression images. (F) Follow-up chest CT after two months exhibits a patchy high-density shadow in the primary lesion (white arrow). The cortical plate was incomplete and swelling was apparent in the surrounding soft tissue.

Figure 2

Microscopic observations of the lesion. (A) Irregularly-shaped bony trabeculae surrounded by numerous fibroblasts. Hematoxylin and eosin (H&E) stain; magnification, ×200. (B) Cell stroma composed of relatively uniform spindle cells and cartilaginous components without significant cellular atypia. H&E stain; magnification, ×100.