June 2007 Tumor Unknown Conference

Case 1 C.G year old male with a history of curretage and bone grafting of a distal ulnar lesion eighteen months ago

Aneurysmal Bone Cyst (ABC)   Osteolytic, hyperplastic, hyperemic-hemorrhagic lesion of unknown origin   Epidemiology   80% before 20 years of age, rare after 30 years old   Most common sites: long bones LE > UE   30% secondary lesions due to pre-existing tumor   Radiographs   Eccentric, expansile, lytic lesion of metaphysis   Cortical attenuation or destruction   Rim of reactive bone   Fluid-Fluid levels on MRI are characteristic

ABC   Histology   Cavernous spaces filled with blood, lacking endothelial lining   Fibroblastic cells, multinucleated giant cells and thin strands of bone

ABC   Treatment   Excision, curettage, and bone grafting   Resection in case of an expendable bone.   Other modalities include adjuvant cryo, chemical cautery, injection of steroids   Radiation not recommended   Prognosis   Local recurrence rate approx 10%, increased if open physis

Case 2 T.K year old male with asymptomatic left ankle swelling for several months

Aneurysmal Bone Cyst (ABC)   Osteolytic, hyperplastic, hyperemic-hemorrhagic lesion of unknown origin   Epidemiology   80% before 20 years of age, rare after 30 years old   Most common sites: long bones LE > UE   30% secondary lesions due to pre-existing tumor   Radiographs   Eccentric, expansile, lytic lesion of metaphysis   Cortical attenuation or destruction   Rim of reactive bone   Fluid-Fluid levels on MRI are characteristic

ABC   Histology   Cavernous spaces filled with blood, lacking endothelial lining   Fibroblastic cells, multinucleated giant cells and thin strands of bone

ABC   Treatment   Excision, curettage, and bone grafting   Resection in case of an expendable bone   Other modalities include adjuvant cryo, chemical cautery, injection of steroids   Radiation not recommended   Prognosis   Local recurrence rate approx 10%, increased if open physis

Case 3 S.P year old male with left hip pain after a minor fall

Unicameral Bone Cyst   Benign fluid filled cystic lesion of bone of unknown cause   Epidemiology   5-15 years of age   Male > Female   Proximal humerus most common, followed by proximal femur

Unicameral Bone Cyst   Symptoms   Asymptomatic unless fracture occurs   Radiographs   Central lytic lesion of metaphysis   Attenuation and slight expansion of cortex   Fluid filled on CT/MRI

  Histology   Thin fibrous membrane lining cyst   Few macrophages, giant cells, leukocytes and slivers of bone and osteoid Unicameral Bone Cyst

  Treatment   Cysts become inactive at skeletal maturity and typically resolve without surgical intervention   Multiple treatments including curettage and bone grafting, steroid injections have been tried with variable efficacy   Fractures tend to lead to resolution of cyst   Displaced fractures are the only absolute surgical indication Unicameral Bone Cyst

Case 4 A.M year old female with an asymptomatic posterior thigh soft tissue mass present for many years, the patient reports that it has increased in size over the past three months

Lipoma   Benign tumor of mature fat   Classification   Superficial: (more common)   contained within subcutis   prevalence for back, neck, proximal limbs   Deep: (less common)   within muscle or intermuscular spaces   Age   Most frequent between years old   Presentation   Slow growing asymptomatic mass

Lipoma   Imaging   Resembles normal fat on all CT and MRI images   Histology   Mature fat cells (lipocytes)   Rarely small areas of hemmorrage, necrosis, calcification   Absence of lipoblasts and pleomorphic, hyperchromatic nuclei differentiate lipoma from liposarcoma   Treatment   Marginal Excision   Local recurrence is rare

  Primary malignant tumor arising from fat   15% of all soft tissue tumors   Usually presents at years of age   Two main types   Myxoid: usually low grade Stage I lesion   Cytogenic marker: reciprocal translocation on chromosome 12   Pleomorphic: usually high grade Stage II lesion Liposarcoma

  Can be very large at presentation due to anatomic location and deep-seated, slow-growing nature   Also typically not painful or tender   MRI   Similar to other soft tissue sarcomas, with multilobular configuration   T1) Low intensity   T2) Bright signal Liposarcoma

  Myxoid Histology   Sheets of lipocytes or lipoblasts interspersed in myxo- matous amorphous matrix with low cell to matrix ratio   Fine branching capillaries with arborization pattern, resemble a road map   Pleomorphic Histology   More cellular   Lacks plexiform capillary network   May have large, bizarre lipoblasts with abundant eosinophilic cytoplasm Liposarcoma

  Treatment   Preoperative adjuvant radiation therapy   Wide surgical excision   Treatment   Wide local excision   Radiotherapy may be used to control local recurrence and lessen the risk of metastasis   Prognosis   Five year survival: well differentiated %, myxoid 75-95%, round cell and pleomorphic 20-50%, dedifferentiated 30%   Local recurrence 10% with adequate margins Liposarcoma

Case 5 T.S year old male with six month history of an anterior shoulder mass

Pleomorphic Sarcoma   Malignant soft tissue tumor of mesechymal origin   Epidemiology   7000 new cases of soft tissue sarcomas diagnosed yearly   Lesions classified according to direction of differentiation   Can be caused by radiation exposure

Pleomorphic Sarcoma   Symptoms   Enlarging mass, most are large, deep and firm at diagnosis   Can be painless or painful   Radiographs   MRI is the best imaging modality

Pleomorphic Sarcoma   Histology   Dedifferentiated mesenchymal cells   Grade of tumors determined on histology   Treatment   Radiation therapy   Wide surgical excision, limb salvage if possible   Prognosis depends on   Tumor Grade   Size (> 5 cm)   Location superficial or deep to fascia

Case 6 D.E year old male with left knee pain after falling from a skateboard three weeks ago

Chondroblastoma   Benign tumor composed of chondroblasts   Epidemiology   Male: female is 3:1   years of age   Localization   Epiphysis, apophysis, or short bone   Extension to metaphysis and even through physeal plate.   Proximal humerus>distal femur>proximal tibia>proximal femur

  Clinical Presentation   Pain, usually referred to a joint   Moderate to long duration   Imaging   XR: Osteolytic with smooth boarders, eccentric   CT/MRI: Well defined boarders, fuzzy mottled intratumoral radio densities Chondroblastoma

  Gross   Rubbery soft with sharp limits toward the surrounding bone   Pink to gray to tan in color   Whitish foci or chalky granules (calcifications)   Histo   Highly cellular: Chondroblasts and Giant cells   Pathognomonic: calcium in fine granules deposited on a reticular network producing a “chicken-wire” pattern Chondroblastoma

  DDX   Giant Cell Tumor, Clear Cell Chondrosarcoma, Chondroma, Chronic Brodie’s abscess   Treatment   Stage 1, 2, and some stage 3: intralesional excision after frozen confirmation   Stage 3: wide intra or extraarticular segmental resection   Prognosis   Local recurrence < 10% after curettage in stage 3 tumors, rare after wide resection Chondroblastoma

Case 7 T.L year old male with left elbow pain and swelling after a fall

Osteomyelitis   Bone Infection   Acute hematogenous, subacute focal disease, and chronic types   Epidemiology   Most common in infants and children   Declining incidence due to better dx/tx   Staph aureus most common in all age groups

Osteomyelitis   Symptoms   Pain, decreased ROM, swelling, erythema, fever, malaise, irritability   Radiographs   Delayed changes on imaging (2-4 weeks)   Lytic lesion with mottled appearance usually in metaphysis   Periosteal elevation/reaction

Osteomyelitis   Histology   Mixed cell population   Sequestrum: dead cortical bone   Involucrum: new cortical bone   Treatment   Biopsy/culture   Acute   IV antibiotics ± surgical debridement   Chronic   IV antibiotics with surgical debridement

Case 8 K.M year old female with a painful soft tissue mass of the left anterior knee

Epithelioid Granulomatous Inflammation   Chronic inflammation   A compact collection of cells of the mononuclear phagocyte system   Types   Low Turnover: Foreign body   High Turnover: Epithelioid, hypersensitivity   Treatment   Marginal excision

Case 9 N.S year old male with a chest wall mass discovered on an x-ray for suspected bronchitis

Calcifying Fibrous Tumor of Pleura   Very rare benign fibrous tumor of pleura   Composed of hyalinised collagen with psam- momatous calcification and inflammatory infiltrate   Rare cases reported in the literature are in patients less than 30 years old   Imaging shows circumscribed lesion with increased density centrally which represents areas of calcification   Treatment is typically excisional biopsy to rule out sarcoma

Case 10 A.Z year old female with left distal thigh pain and swelling for several weeks

B-Cell Lymphoma   Neoplasm of B-Lymphocytes   Most common Non-Hodgkin lymphoma   Fourth through seventh decades   Primary lymph node disease   Extranodal sites   More than 50% of patients will have extranodal involvement at diagnosis   Primary bone lymphomas are rare   (5% of extranodal disease)   Most common site is the thigh

Large B Cell Lymphoma of Soft Tissue   Symptoms   Often mild and prolonged before diagnosis   Radiographs   Lytic lesion with “moth eaten” appearance   Histology   Dense sheets of round cells   CD-20 positive

Large B Cell Lymphoma of Soft Tissue   Treatment   Combined chemotherapy and radiation to bony sites   Chemo: Cytoxan, adriamycin, vincristine, and prednisone   If remission is obtained by 6 cycles of chemo, cure rates approximate 60-70%