Case Report Submitted by: Farhan Amanullah Faculty reviewer: Radiological Category: Muscoloskeletal Principal Modality (1): Principal Modality (2): General Radiography MRI Case Report Submitted by: Farhan Amanullah Faculty reviewer: Sandra Oldham, MD Date accepted: 28 September 2011

Case History This is a 44-year-old AA female with no relevant PMH who arrived to the ER at MHH complaining of near-syncope secondary to “intense pain” in her left thigh. Patient relates her problems to prior surgeries of childhood. The patient reports she had some falls when she was 7 years old while playing kick ball and fractured her left hip. At that time, they put plates and screws in her left hip. Later at about 12 years old, she slipped and fell in the shower and they put a rod into her left femur. At about 14 years old, she had a knock left knee and this was corrected surgically on her left proximal tibia surgery. Patient reports her left femur has given her problems for at least 3 months, where she could not stand or walk for prolonged periods of time and was unable to retain her job. She has been unemployed for three months.

Radiological Presentations Lateral radiograph of L femur Intramedullary rod is seen. The bone appears severely eroded at each of these locations with an approximately 10 cm long gap of bare rod. Around this area, there is a large ovoid soft tissue masslike prominence that measures about 20 cm in craniocaudad dimension by about 10 cm in diameter.

Radiological Presentations AP radiograph of L femur Hardware failure at the femoral head, with protuberance of transcervical screws through the bone cortex and into the acetabular roof.

Radiological Presentations AP radiograph of L femur Intramedullary rod is seen. The bone appears severely eroded at each of these locations with an approximately 10 cm long gap of bare rod. Around this area, there is a large ovoid soft tissue masslike prominence that measures about 20 cm in craniocaudad dimension by about 10 cm in diameter.

Radiological Presentations Cor T1 SE Femur There is an approximately 26 x 10 x 11 cm heterogeneously T1 hypointense centered within the left mid femur. There are areas of cystic change and fluid signal, with multiple small areas of hemorrhage, and small hemorrhage fluid levels are present. There is edema of the surrounding soft tissues, diffuse muscular atrophy.

Radiological Presentations MRI T2 Coronal view of L Femur There is an approximately 26 x 10 x 11 cm heterogeneously T2 hyperintense mass centered within the left mid femur. There are areas of cystic change and fluid signal, with multiple small areas of hemorrhage, and small hemorrhage fluid levels are present. There is edema of the surrounding soft tissues, diffuse muscular atrophy.

Radiological Presentations Axial T1 of left femur, shortly after contrast injection

Radiological Presentations Axial T1 post contrast  heterogenous contrast enhancement

Radiological Presentations There is moderately increased FDG uptake in the large 23 cm long left femoral mass with SUV 6.1, consistent with patient known osteosarcoma. Focally increased FDG uptake is identified in the: left proximal and the distal tibia with SUV maximum 5.5 the left talus with SUV 6.2 multiple foci in the left tarsometatarsal bones and the phalanges with SUV maximum 5.6, corresponding to sclerotic change on CT, consistent with metastasis.

Test Your Diagnosis Which one of the following is your choice for the appropriate diagnosis of the leg lesion? Osteomyelitis Ewing’s Sarcoma Chondrosarcoma Osteosarcoma

Findings and Differentials Radiographs of the L femur and knee demonstrate severely eroded bone with apprx. 10 cm long gap of bare rod which is surrounded by a large ovoid soft tissue masslike prominence that measures 20 cm in craniocaudad dimension by 10 cm diameter. MR demonstrates 26 x 10 x 11 cm heterogeneous mass associated with the left mid and distal femur resulting in diffuse destruction of the surrounding bone. Multiple small areas of hemorrhage, cystic change, and fluid signal are present. Surrounding edema. No inguinal or pelvic lymphadenopathy. PET CT shows multiple “hot” areas of increased FDG uptake. Findings and Differentials Findings: Differentials: Osteomyelitis Ewing’s Sarcoma Chondrosarcoma Osteosarcoma

Discussion Osteomyelitis Ewing’s Sarcoma Chondrosarcoma Osteosarcoma Bone expansion, marked sclerosis, replacement of marrow fat with water secondary to edema, exudate, hyperemia, and bone ischemia. Usually develops during puberty, rare in adults. Radiographs show a long, permeative lytic lesion in the metadiaphysis and diaphysis of the bone, with a prominent soft-tissue mass extending from the bone. Older patients (MC >60 yo). Large osteolytic lesion with extension into soft tissues. Endosteal Scalloping. All of these diagnoses can cause decreased signal intensity in the involved bone on T1-weighted images, increased signal intensity in the involved bone on T2-weighted images. This is the diagnosis.

Radiological Presentations Specimen after left leg above knee amputation.

Radiological Presentations

Radiological Presentations

Radiological Presentations Malignant Spindle Cells and Telangiectasia Large areas of hemorrhage and dilated blood vessels, consistent with the diagnosis of telangiectatic osteosarcoma. Some necrosis is present, occupying approximately 30% of the areas. Approximately 70% of the tumor is viable, admixed with fibroblastic proliferation, hemosiderin laden histiocytes and hemorrhage. In areas, atypical mitoses are present, indicating proliferative tumor cells.

Radiological Presentations Malignant Spindle Cells with large hyperchromatic nuclei and bone formation.

Discussion: Osteosarcoma Mixed lytic & sclerotic lesion Periosteal rxns common Codman’s triangle Calcification as well as soft tissue extension common Males affected more than females Common age group is 10-20 years old Codman’s Triangle (Sunburst or hair-on-end appearance) - triangular area of new subperiosteal bone that is created when a lesion, often a tumour, raises the periosteum away from the bone.

Discussion: Osteosarcoma Location: Usually metaphysis of long bones 60% occur in distal femur/proximal tibia region 42% femur 19% Tibia 10% Humerus 15% pelvis 8% facial bones/cranium

Discussion: Osteosarcoma Presentation Swelling, pain around area of joint Natural History Persistent growth and early metastasis to lungs Prognosis 5-year survival rate = 15 – 20% when treated by resection of primary tumor (amputation) 5-year survival rate = 60% with adjunctive chemotherapy following resection

Discussion: Telangiectatic Osteosarcoma An extremely lytic and destructive variant of classic osteosarcoma Same age group and location Accounts for 0.4-12% of all osteosarcomas The pathologic specimen is hemorrhagic, with microscopic evaluation demonstrating the presence of malignant-appearing stromal cells with giant cells Before aggressive multidrug chemotherapy, prognosis extremely poor Now same as prognosis for patients who have classic osteosarcoma and is treated with similar protocols

Radiological Presentations The patient also received a skeletal survey which revealed deformities and lesions elsewhere in the body. Here are some examples. AP radiograph of R femur There is chronic bowing deformity of the right distal femur.

Radiological Presentations AP radiograph of L femur Left femoral neck chronic bowing deformity.

Radiological Presentations Lateral radiograph of skull There are multiple lytic lesions within the skull. Area of bone thickening around left parietal bone indiciating chronicity.

Radiological Presentations Coronal CT of chest low density and groundglass lesions with sclerotic peripheral margins within the lower sternum that may represent bone infarcts or areas of fibrous dysplasia.

Radiological Presentations Coronal CT of chest, more posterior low density and groundglass lesions with sclerotic peripheral margins within the left scapula.

Findings and Differentials Chronic bowing deformities and multiple bony lesions throughout skeleton. Several groundglass lesions with sclerotic peripheral margins The majority of these lesions demonstrate no increased uptake on a PET CT examination. Findings: Differentials: Multiple Myeloma Multiple Enchondromas Polyostotic Fibrous Dyplasia Metastasis Other ddx of multiple lytic lesions: Brown tumors from hyperparathyroidism, infection, eosinophilic granulomas (Langerhans cell histiocytosis)…up to 80% accompanied by scalp rash.

Discussion: Multiple Myeloma Most common primary malignant neoplasm of the skeletal system. The following 3 criteria makes the diagnosis unequivocal: A minimum 10-15% of a bone marrow aspirate demonstrates plasma cells Monoclonal immunoglobulins present in the urine or blood Radiographic survey demonstrates lytic lesions

Multiple Enchondromas Discussion: Multiple Enchondromas Ollier disease - nonhereditary disorder characterized by multiple enchondromas with a predilection for unilateral distribution. Maffuci syndrome is nonhereditary and is less common than Ollier disease. This syndrome results also in multiple hemangiomas. The lesions replace normal bone with mineralized or unmineralized hyaline cartilage, thereby generating a lytic pattern on radiographs. More commonly, there are lytic areas containing rings and arcs of chondroid calcifications.

Discussion: Fibrous Dysplasia Definition - a sporadic disorder characterized by the presence of one (monoostotic) or more (polyostotic) expanding fibrous skeletal lesions composed of bone-forming mesenchyme

Discussion: Fibrous Dysplasia Equal frequency in both sexes The monoostotic form is the most common and is usually diagnosed in patients between 20 and 30 years of age without associated skin lesions The polyostotic form typically manifests in children <10 years of age and may progress with age the lesions most commonly involve maxilla, other craniofacial bones, ribs, and metaphyseal or diaphyseal portions of the proximal femur or tibia. Expanding bone lesions may cause pain, deformity, fractures, and nerve entrapment

Discussion: Fibrous Dysplasia The lesions are typically well-defined, radiolucent areas with thin cortices and a ground-glass appearance Lesions may be lobulated with trabeculated areas of radiolucency Involvement of facial bones usually presents as radiodense lesions

Discussion: Fibrous Dysplasia Frequency of malignant change is increased in polyostotic forms, especially in patients with concomitant McCune–Albright syndrome. Rate of transformation ~ 4% with MAS and 0.5% with monostotic forms Common tumors: Osteosarcoma Fibrosarcoma Chondrosarcoma Patient’s usually in third or fourth decades of life Anatomic Sites: Craniofacial bones Femur Tibia

Diagnosis Polyostotic Fibrous Dysplasia with secondary malignant degeneration of left femoral lesion into Telangiectatic Osteosarcoma

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