Primary hepatic osteosarcoma: a case report and literature review

Extra-skeletal osteosarcoma (ESOS) is an uncommon malignant soft tissue tumor, primarily seen in the soft tissues of the extremities or the retroperitoneal region. Primary hepatic osteosarcoma (PHO), a unique subtype, is clinically exceedingly rare. Thus far, only isolated instances have been documented in the literature, with limited high-quality study data accessible. Furthermore, there is no definitive clinical consensus regarding the ideal characterization and management of PHO.

This case report details a 67-year-old male patient hospitalized for one month due to abdominal pain. Upon admission, the patient displayed an increased serum alkaline phosphatase level. Computed tomography (CT) and magnetic resonance imaging (MRI) identified a well-defined lesion in the left hepatic lobe. The patient underwent an open left hemihepatectomy to obtain a conclusive diagnosis. Postoperative histological and molecular pathology assessments verified the tumor as a PHO. The patient underwent transhepatic arterial chemotherapy with epirubicin 30mg/m² and cisplatin 40mg/m², succeeded by 3 cycles of MAP regimen chemotherapy (methotrexate, doxorubicin, cisplatin) in conjunction with sorafenib-targeted therapy, achieving a recurrence-free survival (RFS) of 21 months.

With a median age upon presentation of 61 years, PHO primarily affects men. It is identified radiologically by cystic-solid tumors, sometimes accompanied by calcifications, which facilitates early radiological detection. The literature analysis and our case report point to TP53 mutations and aberrant SATB2 expression as possible genetic markers that could close the diagnostic gap for this uncommon and frequently misdiagnosed illness. Preliminary findings indicate that multimodal therapies-surgery, chemotherapy, and targeted therapy-hold promise for improving patient survival despite PHO's high malignancy and poor prognosis.