Adolescent ; Child ; Female ; Hip Dislocation, Congenital ; diagnostic imaging ; pathology ; surgery ; Humans ; Male ; Osteotomy ; methods ; Pelvic Bones ; surgery ; Radiography

Reports of metastatic hepatocellular carcinoma (HCC) without a primary liver tumor are rare. Here we present a case of isolated HCC that had metastasized to the pelvic bone without a primary focus. A 73-year-old man presented with severe back and right-leg pain. Radiological examinations, including computed tomography (CT) and magnetic resonance imaging (MRI), revealed a huge mass on the pelvic bone (13x10 cm). He underwent an incisional biopsy, and the results of the subsequent histological examination were consistent with metastatic hepatocellular carcinoma. The tumor cells were positive for cytokeratin (AE1/AE3), hepatocyte paraffin 1, and glypican-3, and negative for CD56, chromogranin A, and synaptophysin on immunohistochemical staining. Examination of the liver by CT, MRI, positron-emission tomography scan, and angiography produced no evidence of a primary tumor. Radiotherapy and transarterial chemoembolization were performed on the pelvic bone, followed by systemic chemotherapy. These combination treatments resulted in tumor regression with necrotic changes. However, multiple lung metastases developed 1 year after the treatment, and the patient was treated with additional systemic chemotherapy.
Aged ; Bone Neoplasms/*diagnosis/*pathology/radiotherapy ; Carcinoma, Hepatocellular/*pathology/radiography/*secondary ; Chemoembolization, Therapeutic ; Combined Modality Therapy ; Glypicans/metabolism ; Humans ; Keratin-1/metabolism ; Keratin-3/metabolism ; Liver Neoplasms/*pathology/radiography/*secondary ; Magnetic Resonance Imaging ; Male ; Paraffin/metabolism ; Pelvic Bones/*pathology/radiography ; Positron-Emission Tomography ; Tomography, X-Ray Computed

OBJECTIVETo study the clinicopathologic and radiologic features of dedifferentiated chondrosarcoma, focusing on its diagnosis and differential diagnosis.

METHODClinical, radiological and pathologic findings of 14 cases of dedifferentiated chondrosarcoma (including biopsy and surgical specimens) were analyzed by hematoxylin and eosin stained sections and immunohistochemistry.

RESULTSThe mean age of patients was 52 years. The male-to-female ratio was 9:5. The most common sites of involvement were pelvis, femur and humerus, similar to the conventional chondrosarcoma. Radiologically, they were malignant tumors with dimorphic pattern. Grossly, central chondrosarcomas were more common than those of the peripheral. An essential histological feature of dedifferentiated chondrosarcoma was an abrupt interface between the low-grade cartilaginous tumor and high-grade anaplastic sarcoma. The most common dedifferentiated components were osteosarcoma, malignant fibrous histocytoma and fibrosarcoma. False negative diagnosis and erroneous diagnosis were frequent when only one-time biopsy was available.

CONCLUSIONSDedifferentiated chondrosarcoma is a rare subtype of chondrosarcoma with poor prognosis, which has different features of clinical manifestation, imaging features and pathological characteristics, compared to conventional chondrosarcoma and chondroblastic osteosarcoma.

Adult ; Aged ; Bone Neoplasms ; diagnostic imaging ; drug therapy ; pathology ; surgery ; Cell Differentiation ; Chondrosarcoma ; diagnostic imaging ; drug therapy ; pathology ; surgery ; Chondrosarcoma, Mesenchymal ; pathology ; Diagnosis, Differential ; Female ; Femoral Neoplasms ; diagnostic imaging ; drug therapy ; pathology ; surgery ; Follow-Up Studies ; Humans ; Humerus ; pathology ; Male ; Middle Aged ; Neoplasm Recurrence, Local ; Osteosarcoma ; pathology ; Pelvic Bones ; pathology ; Radiography ; Vimentin ; metabolism ; Young Adult