Low-grade fibromyxoid sarcoma (LGFMS) is a rare soft tissue neoplasm most commonly presenting in young to middle-aged adults. LGFMS is an indolent tumour with a deceptively benign histological appearance. Local recurrences are not uncommon and the tumours can metastasise. A particular gene translocation, FUS-CREB3L2, has been shown to occur commonly in cases of LGFMS. The literature suggests that the FUS-CREB3L2 fusion-gene is a specific marker for LGFMS. We report the cytogenetic analysis of 29 cases of LGFMS, and clinical outcomes of 21 patients treated surgically between 1998 and 2008 at our regional bone and soft-tissue tumour centre. The mean age was 45.4 years. The most common location of tumours in our series was the lower limb. The mean follow-up was 30.1 months (range 0 to 125 months). To date, there have been no cases of local recurrence or metastasis. Fifteen of our patients (52.2%) were FUS-CREB3L2 translocation-positive. This suggests either that the translocation incidence in our LGFMS series is lower than other studies, or that reverse-transcriptase polymerase chain reaction (PCR) is substantially less sensitive than the literature suggests. The patients in this series testing positive presented at a younger age (38.2 years, compared to 45.6 years), and had larger tumours than their negative counterparts (mean diameter 97.6mm, compared to 65.2mm), although there was no difference in clinical outcome. We conclude that PCR testing for the FUS-CREB3L2 translocation is a useful tool for confirming the diagnosis of LGFMS, but has no role in predicting short-term clinical outcome. In our experience it is not necessary to perform wide excision, and marginal margins are adequate. Longer-term follow-up is required to elucidate whether the previously reported recurrence and metastasis rates are a true reflection of the nature of this tumour, and may identify differences in the long-term clinical outcome between translocation-positive and negative patients.
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.
