Background: Extraskeletal osteosarcoma is an extremely rare malignant neoplasm. Literature regarding primary osteosarcoma of the uterus is confined to only a small number of case reports. Case: A 57-year-old female with a history of uterine fibroids presented to the emergency department with abdominal pain. Imaging was notable for an enlarged uterus with a 15 cm calcified fibroid extending along the posterior uterus. The patient underwent a laparotomy for total hysterectomy and bilateral salpingo-oophorectomy. Pathological evaluation of the specimen yielded mesenchymal proliferation with osteoid formation and tumor cells with densely eosinophilic cytoplasm resembling osteoblasts with a final diagnosis of primary uterine osteosarcoma. Multidisciplinary tumor board recommended against adjuvant treatment, given the lack of evidence for improved outcomes for early-stage uterine sarcomas. The patient was followed up with surveillance visits every-three months, entailing physical examination and computed tomography(CT) scans. Unfortunately, she had locoregional oligometastatic recurrence of her disease at 1-year follow up.
Conclusion: Primary uterine osteosarcoma is an extremely rare and aggressive neoplasm with limited understanding regarding optimal treatment options.
Keywords: Extraskeletal osteosarcoma; Soft tissue neoplasms; Uterine osteosarcoma.