Several lesions have clinical and radiological characteristics mimicking muscular skeletal tumor. Myositis ossificans usually presents a typical pattern making biopsy unnecessary; nevertheless, in rare cases, neoplasm must be ruled out. Biopsy is often sufficient to allow a diagnosis and a correct related treatment, but, unfortunately, sometimes it may lead to erroneous treatment. We report an unusual case of a lumbar paravertebral mass that had an MRI aspect similar to a chondrosarcoma, a histology pattern based on biopsy compatible with neurinoma and a definitive diagnosis of myosistis ossificans.