Abdominis rectus intramuscular myositis ossificans

Myositis ossificans (MO) is a benign, localized, and self-limiting soft tissue tumor. The condition is associated with prominent heterotrophic bone formation within the muscles, ligaments, and fascia. Clinically, MO could be confused with malignant lesions, such as osteosarcoma and soft-tissue sarcoma. Few reports have described the cytological findings and differential diagnoses of MO and malignant tumors trough diagnostic imaging. Thus, we reviewed the literature on MO. We also report the case of a 48-year-old woman with an abdominal tumor, suspected to be a sarcoma, underwent diagnostic imaging and an open biopsy, which included a histopathological examination. Thereafter, the tumor was surgically excised. Pathology reports confirmed the MO diagnosis. The patient recovered without complications. Clinical presentations along with cytological and radiological findings are helpful in diagnosing MO. Considering MO in the differential diagnosis is necessary for avoiding diagnostic pitfalls and unnecessary investigations, which can have major consequences and complications for patients.