Introduction: Fibrosarcoma of bone is a rare malignant spindle cell tumor.
Case Study: Herein, we present a case of fibrosarcoma in a 40-year-old male who was presented to the clinic with left-sided great toe pain for 20 years. Simple radiographs showed acrolysis at the distal phalanx of great toe. Magnetic resonance imaging (MRI) revealed a 1.5 cm sized heterogenous high signal intensity mass on T2-weighted images and iso signal intensity on T1- weighted images. Dorsal and distal portion of the mass showed markedly dark signal intensity on T1 and T2-weighted images.
Conclusion: In an enhanced image, the mass showed heterogenous enhancement. Surgical removal was performed and pathologic analysis revealed fibrosarcoma. Although extremely rare, fibrosarcoma of the bone should be kept in mind as a possibility when a lesion exhibits a black signal intensity component on an MRI with acrolysis.