Chapter 26: Bone Tumors Flashcards
Where do most primary tumors of bone occur?
Near the metaphyseal area.
Distal femur or proximal tibia.
A benign tumor is discovered that is composed of cortical-type dense bone.
Osteoma.
- Calvarial and mandibular osteomas
- Osteomas of sinonasal and orbital bones
- Bone islands occuring in medullary bones
- Surface osteomas of long bones
A five-year-old presents with bone pain. Radiograph shows a solitary lesion in the metaphysis of the femur that is characterized by a cortical, eccentric position and well-demarcated, central lucent zones surrounded by scalloped, sclerotic margins.
The bone is biopsied and on gross examination the lesion is granular and dark red to brown. Bland spindle cells arranged in an interlacing, whorled pattern with multinucleated giant cells and foamy macrophages.
Nonossifying fibroma. Common, typically regresses.
A solitary fluid-filled unilocular lesion is found in the metaphysis of the proximal humerus of a male child. The radiograph looks like this.
Simple bone cyst.
Can be associated with trauma. Lined by fibrous tissue. Susceptible to pathologic fracture.
A 21-year-old presents with bone pain. Biopsy reveals a spongy mass containing multiple blood-filled cysts. Microscopically, blood-filled spaces separated by cellular fibrous septa with scattered osteoclast-like giant cells and reactive bone.
Aneurysmal bone cyst.
Can be associated with cystic and hemorrhagic transformation of an underlying lesion (chondroblastoma, osteoblastoma, fibrous dysplasia, giant cell tumor, osteosarcoma)
Or primary ABC.
An adolescent boy presents with localized nocturnal bone pain. The pain is quickly relieved by aspirin and exacerbated by alcohol. Upon biopsy, the lesion is a spherical hyperemic tumor that is softer than surrounding bone.
Microscopically, the center of the tumor is composed of thin, irregular trabeculae of woven bone within a cellular and vascular fibrous stroma with osteoblasts and osteoclasts.
Trabeculae are more mature in the center.
Reactive sclerotic bone surrounds the nidus.
Osteoid Osteoma
Benign, painful lesion. Surgical excision or radioablation is curative.
A 20-year-old presents with an incidentally discovered spinal mass. It is painless and appears as a radiolucent lesion with only a thin shell of surrounding bone.
Osteoblastoma.
Larger than an osteoid osteoma.
A mass lesion is discovered in the metacarpals of a patient’s hand. Histology is shown below. The tumor is composed of lobules of hypocellular hyaline cartilage without atypia.
Solitary Chondroma - AKA Enchondroma
A male 20-year-old patient presents with a mass in the proximal femur. On radiograph, it displays an eccentric, radiolucent appearance with sharply defined borders.
The tumor is biopsied and is soft and compact with scattered gray or hemorrhagic areas. By microscopy, primitive chondrocytes are arranged as sheets of round to polyhedral cells. Large ovoid nuclei.
Variably calcified cartilage matrix, appears promitive.
Chondroblastoma. Benign, curettage is treatment of choice.
A tall adolescent male presents with a mass near the knee. Radiograph shows bone destruction and bone formation.
A shell of bone intersects the cortex at one end and and is open at the other*.
Gross appearance is widely variable and shows invasion through the cortex.
Histology shows malignant cells with osteoblastic differentiation prodcuing woven bone. Stain for alkaline phosphatase and osteonectin.
Osteosarcoma.
Radiographic sign known as Codman triangle.
Tumor suppressor genes mutated, Rb or p53.
Associated with Paget’s and radium.
A middle-aged man presents with deep bone pain.
Neoplasic cartilaginous tissue is discovered with necrosis, cystic change, and hemorrhage. Infiltration is discovered.
Chondrosarcoma - develops from cartilage rest or enchondroma. Grade determines prognosis***.
SOX9 expressed
Central: Arises from medullary space
Peripheral: Arises from outside the bone, usually cartilaginous cap of an osteochondroma
Juxtacortical: Metaphysis of long bones.
Clear cell
Dedifferentiated (high grade)
Mesenchymal chondrosarcoma: Blue cell tumor with discrete islands of malignant hyaline cartilage.
Patient presents with bone pain. Radiograph is shown below - eccentric lytic lesion with virtually no new bone formation.
On histology, osteoclast-type giant cells are seen and plump, oval, mononuclear cells.
Giant cell tumor. Rarely metastasizes. Osteoclastic, multinucleated giant cells, randomly and uniformly distributed in a background of proliferating mononuclear cells.
p53, c-myc.
A male child presents with a bone mass. Radiograph shows expansile cortical destruction with poor circumscription and delicate interrupted periosteal reaction.
Biopsy shows uniform small cells with round, dark blue nuclei and poorly defined cytoplasm.
Immunohistochemical stain for CD99 shows membranous pattern (insert).
Ewing Sarcoma - primitive neuroectodermal tumor.
Translocation of the EWS1 gene to the carboxy terminus of the FLI-1 gene.
EWS/ERG fusion protein much worse prognosis.
A 65-year-old presents with pathologic fractures. A radiograph shows lytic bone lesions. Biopsy and microscopy are shown below.
Multiple myeloma
If localized, called plasmacytoma.
Prognosis poor, infection and renal failure common causes of death.
In adults, the most common metastatic tumors to bone are…
Carcinomas of the breast, prostate, lung, thyroid, and kidney.
