Bone neoplasms Flashcards
What are the two main categories of bone tumors?
Primary bone tumors and metastatic bone tumors, with metastatic being more common.
What is the most common primary malignant bone tumor?
Osteosarcoma (35%), followed by chondrosarcoma (25%) and Ewing sarcoma (16%).
What are common clinical features of primary malignant bone tumors?
Pain, swelling, fracture, and loss of function; 20-25% present with metastasis.
What imaging modalities are commonly used to assess bone tumors?
X-ray, MRI or CT, bone scans, PET scans, and biopsy for definitive diagnosis.
What age group is primarily affected by osteosarcoma?
Mostly children and young adults, ages 10-25.
Describe the typical appearance of osteosarcoma on X-ray.
A large, destructive, lytic or blastic mass with a sunburst pattern, often breaking through the cortex.
At what age is chondrosarcoma most commonly seen?
Ages 30-60, more common in males.
What are the key macroscopic features of chondrosarcoma?
Large, lobulated, pearly white or light blue tumors, often with calcifications and myxoid changes.
What is the common age and location for giant cell tumors?
Ages 30-50, often in the epiphyseal-metaphyseal region of long bones, especially around the knee.
Describe the histological appearance of giant cell tumors.
Numerous multinucleated giant cells with stromal cells that resemble the giant cells; no osteoid formation.
What is fibrous dysplasia, and how does it present?
A benign tumor from developmental arrest, presenting as monostotic or polyostotic lesions, sometimes in syndromic forms like McCune-Albright syndrome.
What mutation is associated with fibrous dysplasia?
Somatic gain-of-function mutation in the GNAS1 gene.
List types of bone tumors by lineage classification.
Osteogenic tumors (e.g., osteosarcoma)
Cartilage tumors (e.g., chondrosarcoma, chondroma)
Fibrogenic (e.g., fibrous dysplasia)
Ewing sarcoma/PNET
Giant cell-rich tumors (e.g., giant cell tumor)
Vascular tumors (e.g., angiosarcoma)
Miscellaneous (e.g., Langerhans cell histiocytosis)
What are key prognostic factors for primary malignant bone tumors?
Tumor size, histopathologic grading, tumor location, metastasis presence, and response to chemotherapy (specific to osteosarcoma and Ewing sarcoma).
What are the differences between osteoid osteoma and osteoblastoma?
Both are benign, osteogenic tumors, but osteoid osteoma is usually smaller (<2 cm) and causes significant pain often relieved by NSAIDs, while osteoblastoma is larger, less painful, and commonly found in the spine.
What is Chondromyxoid Fibroma?
A rare benign cartilage tumor that presents as a painful lesion, often located in the metaphysis of long bones, especially in young adults.
How is Chondromyxoid Fibroma differentiated from other cartilage tumors?
It shows a mix of chondroid, myxoid, and fibrous areas and is usually found in metaphyseal regions of long bones.
What are the different types of chondroma?
Enchondroma (within the bone), subperiosteal chondroma (on the bone surface), and soft tissue chondroma (in soft tissue without bone contact).
What conditions are associated with multiple enchondromas?
Ollier’s disease and Maffucci syndrome, with enchondromas located in multiple bones.
What is Ewing Sarcoma, and what age group does it primarily affect?
A highly malignant small round cell tumor primarily affecting children and young adults, with common sites including the pelvis, femur, and ribs.
What genetic abnormality is associated with Ewing Sarcoma?
A translocation between chromosomes 11 and 22 [t(11;22)], creating an EWS-FLI1 fusion gene, which aids in diagnosis.
What is an osteochondroma?
A common benign bone tumor with a cartilage cap, arising as an exostosis attached to the bone by a bony stalk.
What genetic mutations are associated with multiple hereditary osteochondromas?
Mutations in EXT1 and EXT2 genes.
What factors are used to grade chondrosarcoma?
Cellular density, nuclear atypia, and mitotic activity of chondrocytes, with grades ranging from well to poorly differentiated (Grade 1-3).
Why is grading important in chondrosarcoma?
Higher-grade chondrosarcomas are more aggressive, with increased likelihood of metastasis to the lungs.
What is a giant cell reparative granuloma?
A benign reactive lesion often found in the jaw and small bones of the hands and feet, containing numerous giant cells in a fibrous stroma.
What are common types of vascular tumors in bone?
Angiosarcoma (malignant), epithelioid hemangioendothelioma (EHE), and benign hemangiomas
How is angiosarcoma identified in bone?
It is a highly aggressive tumor with vascular differentiation, often presenting as painful, lytic lesions.
What is Langerhans Cell Histiocytosis, and how does it affect bone?
A disorder where Langerhans cells proliferate abnormally, causing lytic bone lesions, often in children and commonly affecting the skull, pelvis, and long bones.
What are two syndromes associated with polyostotic fibrous dysplasia?
Mazabraud syndrome (with soft tissue myxomas) and McCune-Albright syndrome (associated with café-au-lait spots and endocrine abnormalities like precocious puberty).
What are some subtypes of osteosarcoma?
Conventional (most common), telangiectatic, parosteal, periosteal, and high-grade surface osteosarcomas, each with unique radiological and histological features.
Which subtype of osteosarcoma has a better prognosis?
Parosteal osteosarcoma generally has a better prognosis compared to other high-grade types due to its low-grade, slow-growing nature.
What is a key histological feature of osteosarcoma?
The presence of a lace-like pattern of osteoid (immature bone matrix) produced by malignant cells.
What radiological sign is commonly associated with osteosarcoma?
The “sunburst” pattern, resulting from periosteal reaction and new bone formation in soft tissue.
What is the clinical presentation of chondrosarcoma?
Progressive pain, swelling, and sometimes a palpable mass, often affecting long bones, pelvis, and ribs.
Why is chondrosarcoma typically not treated with chemotherapy?
Chondrosarcoma is relatively chemo-resistant; treatment often relies on surgical resection.
How can enchondroma be differentiated from low-grade chondrosarcoma?
Enchondromas are benign, often asymptomatic, and slow-growing, while chondrosarcomas show aggressive features such as pain, cortical destruction, and permeative growth.
What is a distinguishing feature of giant cell tumors on imaging?
Eccentric, lytic lesions typically located in the epiphysis of long bones with a “soap bubble” appearance.
Why is giant cell tumor considered benign but locally aggressive?
It can cause significant bone destruction and has a high recurrence rate, but metastasis is rare.
What is a characteristic microscopic feature of fibrous dysplasia?
“Chinese character” trabeculae—curvilinear, woven bone spicules within a fibrous stroma without osteoblastic rimming.
What distinguishes polyostotic fibrous dysplasia from monostotic?
Polyostotic affects multiple bones and may be associated with syndromic presentations, while monostotic affects a single bone.
What is adamantinoma, and where is it typically found?
A rare, low-grade malignant bone tumor, commonly found in the tibia, characterized by epithelial-like cells in a fibrous stroma.
How is adamantinoma distinguished from osteofibrous dysplasia?
Adamantinoma is locally aggressive and may metastasize, whereas osteofibrous dysplasia is benign and non-metastasizing.
What is a key histological feature of Langerhans Cell Histiocytosis in bone?
Presence of Langerhans cells with characteristic “coffee bean” nuclei and eosinophilic cytoplasm, often accompanied by eosinophils.
How does Langerhans Cell Histiocytosis present clinically?
Bone pain and lytic lesions, commonly in children, affecting sites like the skull, pelvis, and long bones.
What is the typical presentation of a hemangioma in bone?
A benign, usually asymptomatic vascular tumor, often incidental on imaging with a “honeycomb” or “polka-dot” appearance.
Where are bone hemangiomas most commonly located?
Vertebrae and skull.
What is epithelioid hemangioendothelioma (EHE)?
: A rare, low-to-intermediate grade malignant vascular tumor affecting bones, with potential for metastasis.
Which bones are commonly affected by EHE?
Often occurs in long bones, pelvis, and spine, presenting with pain and swelling.
How does multiple myeloma typically affect bones?
Causes lytic “punched-out” lesions, bone pain, and increased fracture risk due to osteoclast activation and bone resorption.
What is a common laboratory finding in multiple myeloma?
Elevated monoclonal protein in serum or urine (M-protein) and hypercalcemia.
What are common primary cancers that metastasize to bone?
Breast, prostate, lung, kidney, and thyroid cancers
How does metastatic bone disease typically present?
Pain, pathological fractures, and hypercalcemia due to osteolytic or osteoblastic lesions.
