A rare case of low-grade myofibroblastic sarcoma of the femur in a 38-year-old woman: a case report

Raman Arora,Amit K Dinda,Alok Sharma,Ruchika Gupta

doi:10.1186/1752-1947-4-121

Abstract

IntroductionPrimary myofibroblastic sarcoma of the bone is a rare spindle cell tumour with, to the best of our knowledge, only eight cases reported in the available English language literature. The disease's rarity and its low-grade features make an accurate diagnosis difficult in most cases. The differential diagnoses of this unusual tumour include various benign entities as well as other sarcomas. Due to the difference in prognosis, a precise pathologic diagnosis is essential, which requires a combination of thorough morphologic examination, immunohistochemistry and electron microscopy wherever available.Case presentationWe report the case of a 38-year-old Indian woman with a lytic lesion in her left femur. The tumour was associated with cortical destruction and soft tissue extension. A biopsy from the soft tissue component showed features suggestive of a low-grade malignant mesenchymal tumour. Excision of the tumour was performed and histopathological examination showed a low-grade spindle cell sarcoma with collagenous stroma. Expressions of vimentin and smooth muscle actin were also noted. Ultrastructural examination confirmed its myofibroblastic nature. A final diagnosis of low-grade myofibroblastic sarcoma of the left femur was thus rendered.ConclusionLow-grade myofibroblastic sarcoma is one of the rarer osseous spindle cell sarcomas depicting a favourable prognosis in the cases reported so far. Its diagnosis requires ancillary techniques like immunohistochemistry and electron microscopy. To the best of our knowledge, we report the ninth case in the literature and the first case from our subcontinent.

Highlights

Primary myofibroblastic sarcoma of the bone is a rare spindle cell tumour with, to the best of our knowledge, only eight cases reported in the available English language literature
Low-grade myofibroblastic sarcoma is one of the rarer osseous spindle cell sarcomas depicting a favourable prognosis in the cases reported so far
Primary myofibroblastic sarcoma of the bone is rare with only eight cases reported in the available English language literature [3,4,5,6,7,8]

Summary

Conclusion

Low-grade myofibroblastic sarcoma is an unusual osseous neoplasm. It needs to be differentiated from other spindle cell tumours of the bone using immunohistochemical expression pattern and/or electron microscopy. The biologic behaviour of this rare neoplasm is difficult to predict because only a few cases have been reported so far. Reports of more cases in the literature would help clinicians define this entity better. Consent Written informed consent was obtained from our patient for publication of this case report and any accompanying images. RG reviewed the literature and drafted the manuscript. AS assisted in drafting and revising the manuscript. AKD was in-charge of signing out the case and critically revised the manuscript. All authors read and approved the final manuscript.

Introduction

Discussion