Granular cell tumours: a rare entity in the musculoskeletal system.

Granular Cell Tumours are rare mesenchymal soft tissue tumours that arise throughout the body and are believed to be of neural origin. They often present as asymptomatic, slow-growing, benign, solitary lesions but may be multifocal. 1-2% of cases are malignant and can metastasise. Described series in the literature are sparse. We identified eleven cases in ten patients treated surgically and followed-up for a period of over 6 years in our regional bone and soft tissue tumour centre. Five tumours were located in the lower limb, four in the upper limb, and two in the trunk. Mean patient age was 31.2 years (range 8-55 years). Excision was complete in one case, marginal in five cases and intralesional in five cases. No patients required postoperative adjuvant treatment. Mean follow-up was 19.3 months (range 1-37 months). One case was multifocal, but there were no cases of local recurrence or malignancy. Histopathological and immunohistochemical analysis revealed the classical granular cell tumour features in all cases. We believe this case series to be the largest of its type in patients presenting to an orthopaedic soft tissue tumour unit. We present our findings and correlate them with findings of other series in the literature.