Pathology of MSK Tumours II Flashcards
What are some features of soft tissue tumours?
May present as lump or swelling, may be associated with pain or discomfort, superficial lesions less likely to be malignant
What are some examples of soft tissue tumours?
Ganglion cysts, rheumatoid nodules, gouty tophus, tenosynovitis, proliferative conditions, benign tumours, malignancy
What are some features of nodular fasciitis?
Self-limiting, cellular proliferation of fibroblastic and myofibroblastic cells, upper age limit of young adults, rapidly growing tumour
How does nodular fasciitis appear?
Superficial or deep, usually less than 5cm, circumscribed, very cellular, plump cells, stellate and spindle, cells mature towards periphery
What are some features of myositis ossificans?
Associated with insertions of large muscles of arms and legs, cellular proliferation but with evidence of bone formation and zonation
How does Dupuytren’s contracture appear?
Firm grey-white tissue, nodules and fascicles, bland fibroblasts and dense collagen
What are some features of deep fibromatosis?
Desmoid tumour, large infiltrative masses, don’t metastasise, commonly teens-age 30, associated with mutation of APC and beta-catenin genes
What are some common sites of deep fibromatosis?
Limb girdles, mesenteric tissue, musculo-aponeurotic tissue of abdominal walls
What are some examples of tenosynovitis?
Giant cell tumours of tendon sheath = digits and wrist, excise and rarely recur
Pigmented villonodular synovitis = large joints, likely to recur
What are some classes of lipomas?
Simple lipoma, intramuscular lipoma, fibrolipoma, angiolipoma (spindle cell, pleomorphic, atypical)
Where do lipomas occur?
Usually on neck, must be superficial
What are some features of liposarcomas?
One of most common sarcomas, patients aged 50-60, deep soft tissue of extremities or retroperitoneum, subtypes (well differentiated, myxoid, pleomorphic)
What measures are used to grade sarcomas?
Degree of differentiation
Degree of proliferation:mitotic count
Presence of coagulative necrosis
What are some examples of leiomyomas?
Uterine (fibroid), leiomyoma of erector pilae or rarely in deeper soft tissues/muscularis of GI tract
How do leiomyomas appear?
Soft tissue leiomyomas usually 1-2cm, fascicles of spindle cells, cigar shaped nuclei, minimal atypia and few mitoses
What are some features of leiosarcomas?
More common in females, deep soft tissue of extremities and retroperitoneum, recur if exclusion not complete, lethal due to local invasion and metastasis
What are some examples of benign cartilaginous tumours?
Enchondroma = digits, can be part of syndrome (Ollier’s and Maffuci)
Osteochondroma
Chondromyxoid fibroma
What do chondrosarcomas produce?
Cartilage
What are some types of chondrosarcomas?
Conventional (90%) = intramedullary or juxtacortical
Clear cell, mesenchymal, dedifferentiated
Who gets chondrosarcomas?
More common in adults >40
Clear cell and mesenchymal affect younger patients
Where do chondrosarcomas occur?
Axial skeleton, head and neck
Clear cell arises in epiphyses of long bones
What are some characteristics of chondrosarcomas?
Bulky tumours, nodules of grey/white tissue, locally invasive in bone and into muscle and fat
How are chondrosarcomas graded?
Grade 1-3
Lost conventional tumours are grade 1
Grade 3 tumours often metastasise to lungs
How do dedifferentiated chondrosarcomas appear?
Low grade with separate high grade components that don’t produce cartilage
How do clear cell chondrosarcomas appear?
Abundant clear cytoplasm
How do mesenchymal chondrosarcomas appear?
Sheets of well differentiated hyaline-appearing cartilage with surrounding small round cells
What are some benign bone tumours?
Simple osteoma = cranial bones, multiple is Gardner’s syndrome
Osteoid osteoma = <2cm, young men, mostly femur and tibia, severe nocturnal pain
Osteoblastoma = involve vertebrae posteriorly, pain not responsive to aspirin
What do osteosarcomas produce?
Osteoid matrix or mineralised bone
What are some features of osteosarcomas?
Most cases in <20 year olds, more common in men, cases in adults secondary to Paget’s/infarcts/radiation,
usually long bones around knee, painful mass, sudden fracture
What genes are linked to osteosarcoma?
Mutations in Rb, TP53, INK4a and MDM2
How are osteosarcomas classified?
Site, grade, primary/secondary, osteoblastic/chondroblastic/fibroblastic/telangiectatic
How do osteosarcomas spread?
Haematogenous spread, aggressive disease = treated with chemo and surgery
What are some tumours of unknown origin?
Ewing’s sarcoma, synovial sarcoma, undifferentiated pleomorphic sarcoma, giant cell tumour (osteoclastoma), aneurysmal bone cyst, pathological fracture
What are some features of Ewing’s sarcoma?
Malignant, aged <20, diaphysis of long bones and pelvis, painful enlarging mass, destructive lesion, primitive round cells, no obvious line of differentiation
What are some features of synovial sarcomas?
Malignant, aged 20-40, deep seated mass around knee joint, also chest and head and neck, can combine areas of spindle and epithelial cells (biphasic) or b monophasic
How should synovial sarcomas be treated?
Can metastasise so treat aggressively with surgery +/- chemo
What are some features of undifferentiated pleomorphic sarcomas?
Malignant, deep soft tissue of extremities (often thigh), 10-20cm, necrosis and haemorrhage, pleomorphic cells, aggressive
What are some features of giant cell tumours (osteoclasts)?
Benign but locally aggressive, aged 20-40, usually solitary, arise in epiphysis of femur and tibia, thin shell reactive bone, treat with curettage
What may giant bone cells cause?
Arthritis-like symptoms or fractures may occur, destroy cortex and expands into soft tissue, can become cystic
What are some features of aneurysmal bone cysts?
Most common aged <20, metaphysis of long bones and posterior elements of vertebral bodies, pain and swelling, lytic lesion with smooth margin and thin bone shell
What are some associations of aneurysmal bone cysts and how are the condition treated
Associated with giant cell tumours and chondroblastomas; treated with curettage or resection
What are pathological fractures?
Fracture through abnormal bone = spontaneous or with minimal trauma
Many causes = osteopenic conditions, tumours
