Periosteal ganglion of the tibia

Abstract

A 40 years old female patient was referred with a painless, taut elastic mild swelling at the proximal anteromedial aspect of her shin. Conventional radiographs were negative. With ultrasound a well defined partially lobulated, anechoic and septated noncompressible cystic lesion was found measuring 4 x 2.5 cm (Fig. 1). Periosteal spurs were visible at the attachments of the cystic septae. With MRI, five sharply demarcated oval lesions were visible in a chainlike order on the bony surface (Fig. 2). Histologically, this material was composed of bland, collagenous, fibrous membranes with small myxoid areas resulting in the diagnosis of a periosteal ganglion. Ganglia are benign cystic lesions that contain mucopolysaccharide-rich fluid within fibrous tissue and in some cases muscle, bone, or semilunar cartilage [1]. Synovial herniation or mucoid tissue degeneration are two suggested mechanisms for their development. Usually they are attached to tendon sheaths. Only few cases of subperiosteal localization have been described with a high preponderance of the tibia. The use of ultrasound in the diagnosis of a periosteal ganglion of the tibia has been mentioned by one author [2]. Ganglia around the knee have been regarded as belonging to a distinct group of cystic masses with a tunnel between them and the joint cavity [3]. The “chain-like” morphology of the lesion presented here underscores that periosteal ganglia of the tibia should be counted within the group of paraarticular knee ganglia and favours the hypothesis of an articular origin of such a lesion which may be a potential cause of recurrency after surgical treatment.