3.P.28 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 an asymptomatic slow-growing benign solitary lesion but may be multifocal. One to two percent of cases are malignant and can metastasise. Described series in the literature are sparse. We examined our database and identified eleven cases in ten patients treated surgically and followed-up for a period of over six years (May 2002 to January 2009) 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 axial skeleton. Mean patient age was 31.2 years (range 8 to 55 years). Excision was complete in one case, marginal in five cases and intra-lesional in five cases. No specimens showed evidence of malignancy. No patients required postoperative adjuvant treatment. Mean follow-up was 19.3 months (range 1 to 37 months), with no cases of local recurrence. One case was multi-focal. Histopathological examination revealed the classical features of granular cell tumour in all cases. Typically, tumour cells were diffusely and strongly positive for S100 protein by immunohistochemistry, whereas the other markers tested were negative. 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 it with findings of other series in the literature.