Periosteal ganglion of the tibia

Periosteal ganglion cyst of tibia: A rare case report

INTRODUCTION AND IMPORTANCE

Periosteal ganglion cyst is a rare disorder, found only in 55 out of 100,000 people annually. Periosteal ganglion location may cause partial external cortical destruction with irregular saucerization and erosion. This report presents a rare case of periosteal ganglion cyst that occurred of the cruris sinistra.

CASE PRESENTATION

A male patient, 68 years old, came with complaint of a lump in the left cruris since one year ago. Nine months later, the lump has increased in size like a chicken egg and still felt painless. MRI result revealed a well-circumscribed multilocular cystic lesion in the peri-osseous soft tissue of the tibia. We performed directly excisional biopsy within the mass, and the histopathology result was periosteal ganglion cyst.

CLINICAL DISCUSSION

The exact pathogenesis of periosteal ganglion is unclear. Synovial herniation and mucoid degeneration of the connective tissue of the periosteum are two suggested mechanisms. In some cases, ganglion cysts may compress nearby nerves. Surgical treatment is recommended for patients who still experience symptoms after non-surgical management has failed. Complete resection of the cyst and surrounding periosteum is recommended to prevent recurrence. After 6 months post-operative follow up clinical examination, no recurrence symptoms founded on the patient.

CONCLUSION

Periosteal ganglion is a rare lesion and may mimic other bone surface lesions. Resection of the periosteal ganglion cyst with surrounding periosteum is important to prevent recurrence.

Bony changes of the tibia secondary to pes anserine bursitis mimicking neoplasm

OBJECTIVE

To describe the radiological features of pes anserine bursitis with intramedullary extension and cortical scalloping and to determine the prevalence of these bony changes among patients with pes anserine bursitis.

MATERIALS AND METHODS

Reports of knee magnetic resonance imaging (MRI) examinations performed at our institution between July 2007 and June 2017 in patients with pes anserine bursitis were retrospectively reviewed, and a total of 542 cases showing MR evidence of pes anserine bursitis were identified. From these, cases of pes anserine bursitis with intramedullary extension and cortical scalloping were identified. Two experienced musculoskeletal radiologists evaluated the MRI by consensus. The medical records of these patients were also reviewed.

RESULTS

Eight patients were diagnosed with pes anserine bursitis with bony changes (prevalence, 1.47% [8 out of 542]), over the study period. All of these patients had a history of chronic knee pain. Seven patients also underwent radiography at the time of diagnosis; these images demonstrated variable appearances depending on the depth of the cortical scalloping and intramedullary extension. On MRI, all patients demonstrated a mass-like fluid extension around the pes anserine bursa and into the bone. None of the patients underwent biopsy; diagnosis was based on MRI features alone.

CONCLUSION

Pes anserine bursitis with intramedullary extension is an unusual presentation of bursitis that may simulate a neoplasm clinically and radiologically. To avoid misdiagnosis, radiologists should be aware of the occurrence of osseous changes in the tibia confluent with pes anserine bursitis.