Pigmented Villonodular Synovitis Arising from Calcaneocuboid Joint in an Army Staff: A Case Report.

Pigmented villonodular synovitis (PVNS) is a locally destructive benign lesion usually affecting the synovial tissue of weight-bearing joints. Herein we reported a 20-year-old male patient who was an army staff with a foot lesion which was painful in army boots. In the beginning, the lesion was considered a ganglion cyst. Further investigations revealed cortical erosion of cuboid bone on the radiograph. Pigmented villonodular synovitis was considered as a probable diagnosis after observation of low signal lesion around the calcaneocuboid joint on both T1 and T2 images of Magnetic Resonance Imaging. The treatment included excision of the lesion and synovectomy of the calcaneocuboid joint. The diagnosis was confirmed with histological studies. At more than one year follow-up, the patient was completely asymptomatic, and there was no evidence of recurrence. This study aimed to raise the awareness of clinicians about the diagnosis of this rare soft tissue neoplasm which might be misdiagnosed as a ganglion or synovial cysts in the hindfoot zone.