Fluid-fluid levels in bone tumors: A pictorial review

Transcription

1 Fluid-fluid levels in bone tumors: A pictorial review Poster No.: C-578 Congress: ECR 2009 Type: Educational Exhibit Topic: Musculoskeletal Authors: L. Figueroa Nasra, C. Martín Hervás, M. Tapia-Viñé, D. Bernabeu Taboada, F. López Barea, V. Pérez Dueñas; Madrid/ES Keywords: MRI, computed tomography, bone tumors, Fluid-fluid levels DOI: /ecr2009/C-578 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. Page 1 of 18

2 Learning objectives To describe the features fluid-fluid levels (FFL) on bone tumors with various imaging modalities, highlighting the value of this sign. To review the bone tumors that may present FFL, emphasizing their most important imaging findings, differential diagnoses, and pathologic correlation. Background Is not a frequent finding in bone tumors but have been described in both benign and malignant tumors and are an important sign that can be useful in the differential diagnosis. They initial report as imaged by magnetic resonance imaging (MRI) was described for aneurysmal bone cysts, but have been also seen in other entities: Chondroblastoma. Condromixoid fibroma. Fibrous dysplasia. Giant cell tumor. Intraosseous lipoma. Osteoblastoma. Simple bone cyst. Telangiectatic osteosarcoma. FFL may occur whenever substances of differing densities are contained within a cystic on compartmentalized structure. The levels are depicted when imaging is performed in a gravity-dependent plane (axial or sagittal slice orientation). The true fluid nature of the cysts can be revealed by the persistence of the horizontal orientation of the FFL following repositioning of the patient. Develop as a result of haemorrhage and subsequent breakdown of blood products (extracellular methemoglobin), tumor necrosis with sedimentation of tumour cells and tissue fluid or separation of blood and serum in large blood filled cavernous spaces. Not indicate aggressiveness and recent work on bone tumours suggests that the proportion of FFL is inversely related to the likelihood of malignancy. Page 2 of 18

3 These can be studied with computed tomography (CT), but MRI is the most useful technique detecting FFL due to its high sensitivity to haemorrhage and excellent tissue contrast. It has been suggested that high signal in the superior layer on short TE sequences is suggestive of malignancy suggesting fresh haemorrhage or necrosis. We reviewed our experience with bone tumors that showed FFL on CT or MRI. Typical signs and morphological features of these tumours will be reviewed. Pathologic correlation, including results of the dissection of gross specimens and examination of the fluid within cavities, was available in all patients. Imaging findings OR Procedure details ANEURYSMAL BONE CYST (ABC) Rare, benign, but locally destructive bone tumors. Expansible lesion containing multiple thin-walled, blood filled cystic cavities. 6% of primary bone lesions. Clinical Features 80% are found in patients from 5 to 20 years of age. Slight female predominance. Most commonly occur within the long tubular bones (70-80%), but they are also found in the pelvis (5-10%), hands (10-15%) and in the spine (posterior elements) (15%). Metaphysis: 80-90%. Intramedullary (most common). Size: 2-20 cm. Primary ABC: It arises de-novo in bone without recognizable pre-existing lesion. Secondary ABC: Arises in preexisting lesion (up to one third of cases) or in areas of previous fracture. Pain and swelling are common presenting symptoms, and pathologic fractures often occur (20%). Regression can occur, but is rare. No malignant transformation. Treatment includes curettage, cryosurgery and bone grafting, with a recurrence rate of 10-20%. Histology "Blood-filled sponge". FFL represent sedimentation of red blood cells and serum within cystic cavities. Page 3 of 18

4 Blood filled spaces alternating with more solid areas lined by single layer of flat undifferentiated cells and fibrous lining contains giant cells. Radiologic Features Radiography: Eccentric, geographic lytic lesion, often with septations. The inner margin is well defined, with the cortical surface expanded or ballooned and with thin periosteal reaction. CT: Intact, thin cortex. No enhancement of cystic components. FFL have 87.5 % sensitivity, 99.7% specificity, 99.7% negative predictive value, 87.5% positive predictive value, and 99.4% accuracy for the diagnosis of ABC. MRI: Cyst of different signal intensity (different stages of blood products) in T1 (T1w) and T2 (T2w) weighted images. Thin, well-defined rim of low-signal intensity surrounding lesion (periosteal membrane). No enhancement of cystic components. Sepal components can enhance ("honeycomb appearance"). Page 4 of 18

5 Fig.: Figure 1. Aneurysmal bone cyst. (a) Lateral knee radiography in a 17-year-old boy shows an eccentric, geographic lytic lesion in the distal metaphysic of the femur with ill-defined margins and soft tissues mass associated. (b) Axial non-enhanced CT image depicts the parosteal mass with intact cortex. Note the presence of fluid-fluid levels. Axial (c) T1-weighted and sagittal (d) T2-weighted MRI reveal cyst of different signal intensity with thin, well-defined rim of low-signal intensity surrounding lesion Page 5 of 18

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7 Fig.: Figure 2. Aneurismal bone cyst. Coronal T2-weighted image in a 30-year-old woman with back pain shows a multichambered heterogeneous mass in the sacrum with intermediate-high signal intensity and fluid-fluid levels. CHONDROBLASTOMA (CODMAN TUMOR) Uncommon, solitary, and benign cartilaginous neoplasms. 1-2% of all bone tumors. Clinical Features 90% occur between the ages of 5 and 25 (immature skeleton). Male to female predominance of 2:1. The proximal and distal femur is the most common locations (43%), followed by the proximal humerus (18%), proximal tibia (17%), as well as the hands and feet (10%). Arise in the epiphysis or apophysis (40%), and can extend into the metaphysis in 25-50% of cases. Size: 2-6 cm. Clinical profile: Local pain, swelling, and tenderness. It may simulate a synovial process, and may be accompanied by an effusion in up to 30% of cases. May become locally aggressive. Pulmonary implants: Rare. Local recurrence after treatment may occur in 5-10%. Histology Proliferation of immature cartilage cells (chondroblast-like) in epiphyseal cartilage plate. Foci of calcification and hemorrhage. Mature chondroid extracelular matrix component. Radiologic Features Radiography: Geographic round/oval lytic and usually eccentric lesion with thin sclerotic margin. A calcified chondroid matrix is noted in 40-50%. A periosteal reaction may also be seen. They may extend thorough growth plate into metaphysic or through cartilage into joint. CT: Helpful in evaluating calcified chondroid matrix. FFL. MRI: There is low signal on T1w, with variable T2w signal characteristics. Enhancement of edematous areas and might suggest aggressive/malignant lesion due to extensive surrounding edema. 21% have cystic features (grossly and histologically) specimens, which account for the FFL seen on imaging. Joint effusions 30-50%. Page 7 of 18

8 Fig.: Figure 3. Chondroblastoma. Postero-anterior radiography (a) and coronal nonenhanced CT images show a geographic round, lytic, eccentric lesion with thin sclerotic margin located in the epiphysis of the right humerus. No calcified chondroid matrix is noted. Sagittal (c) T2-weighted images shows a hyperintense mass with subtle fluidfluid levels. Note the presence of bone marrow edema. (d) Histological specimen depicts the proliferation of immature cartilage cells (chondroblast-like) with foci of hemorrhage. CONDROMIXOID FIBROMA Page 8 of 18

9 Benign tumor composed of immature myxoid mesenchymal tissue with features of primitive cartilaginous differentiation. 0.5% of all primary bone tumors. Clinical Features 5-79 years-old. Male to female predominance of 1.5-2:1. Long bones: 60%. Predilection for proximal tibia. Metaphyses: 95%. Size: 1-10 cm. Clinical presentation: Local swelling and pain. Asymptomatic in 10%. Pathologic fracture in 2-5%. Malignant degeneration: Rare. Recurrence in 25% after curettage. Radiation therapy contraindicated due to risk of malignant transformation. Histology Composed of mixture of chondroid, myxoid, and fibrous tissues. Hemorrhagic and cystic foci can be seen. Dense chondroid matrix. Expression of type II collagen, S100B. Radiologic Features Radiography: Geographic and expansile eccentric lytic lesion with well-defined sclerotic margin and internal septa. Matrix calcification rare. No visible periosteal reaction (unless fractured). CT: Most sensitive modality to evaluate chondroid matrix calcification. Enhancement. MRI: Intermediate to low signal intensity on T1w. High signal on T2w in the lesion and soft tissues affected. Heterogeneous enhancement. FFL. FIBROUS DYSPLASIA Images for this section: Page 9 of 18

10 Fig. 1: Figure 1. Aneurysmal bone cyst. (a) Lateral knee radiography in a 17-year-old boy shows an eccentric, geographic lytic lesion in the distal metaphysic of the femur with ill-defined margins and soft tissues mass associated. (b) Axial non-enhanced CT image depicts the parosteal mass with intact cortex. Note the presence of fluid-fluid levels. Axial (c) T1-weighted and sagittal (d) T2-weighted MRI reveal cyst of different signal intensity with thin, well-defined rim of low-signal intensity surrounding lesion Page 10 of 18

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12 Fig. 2: Figure 2. Aneurismal bone cyst. Coronal T2-weighted image in a 30-year-old woman with back pain shows a multichambered heterogeneous mass in the sacrum with intermediate-high signal intensity and fluid-fluid levels. Fig. 3: Figure 3. Chondroblastoma. Postero-anterior radiography (a) and coronal nonenhanced CT images show a geographic round, lytic, eccentric lesion with thin sclerotic margin located in the epiphysis of the right humerus. No calcified chondroid matrix is noted. Sagittal (c) T2-weighted images shows a hyperintense mass with subtle fluid-fluid levels. Note the presence of bone marrow edema. (d) Histological specimen depicts the proliferation of immature cartilage cells (chondroblast-like) with foci of hemorrhage. Page 12 of 18

13 Fig. 4: Figure 4. Fibrous dysplasia. Axial (a) and coronal (b) T1-weighted images depict expansile hyperintense lesion located in the medullary cavity of the right humerus. Fig. 5: Figure 5. Giant cell tumor. (a) Postero-anterior radiography of the right knee in a 18-year-old man shows a lytic epiphyseal, eccentric, septated and expansile lesion which Page 13 of 18

14 extends to subchondral bone without surrounding sclerosis. (b) In the grossly specimen note the secondary blood-filled cyst formation. Fig. 6: Figure 6. Giant cell tumor. (a) Postero-anterior radiography of the elbow shows a lytic eccentric lesion in the distal methaphysis of the humerus. Axial (b) and coronal (c) T2-weighted images show the hyperintense lesion with fluid-fluid levels. (d) Photography of the surgery procedures. Page 14 of 18

15 Fig. 7: Figure 7. Intraosseous lipoma. Lateral right foot radiography in a 50-year-old man shows an osteolytic lesion with a well-defined sclerotic border and central calcification. Coronal (b) T1-weighted and salgittal (c) T2-weighted MRI depict that the lesion follow subcutaneous fat signal intensity. Page 15 of 18

16 Fig. 8: Figure 7. Telangiectatic osteosarcoma. (a) Lateral plain film and sagittal (b) CT images in a 15-year-old women show a parosteal lytic lesion in the posterior aspect of the tibia. Note the presence of an important soft-tissue mass with calcified matrix. Axial (c), coronal (d) and sagittal (e) T2-weighted MRI depicts multiple predominantly hightsignal intensity cystic cavities separated by septations with cortical destruction and fluidfluid levels. (f) Histological specimen demonstrates the osteoid produced by pleomorphic malignant cells mixed with osteoclast giant cells. Page 16 of 18

17 Fig. 9: Figure 8. Osteoblastoma. Axial CT image of a vertebral body shows a expansile and circumscribed lytic lesion with reactive sclerosis and cortical expansion in the right pedicle. The lesion presents central calcification and matrix. (b) Axial T2-weighted MRI depicts a intermediate signal intensity lesion with foci of signal void and soft-tissues extents. sourrounding inflammatory reaction. (c) Photography of the surgical act. Fig. 10: Figuere 9. Metastatic hypernefroma. Axial (a) and coronal (b) T2-weighted MRI in a 60-year-old man shows a hyperintense lytic lesion in the metaphysis-diaphysis of the left femur that destroy the cortical and has important soft-tissues comprise. Note the presence of fluid-fluid levels. Page 17 of 18

18 Conclusion FFL is a non-specific finding but its presence can significantly aid in formulating a limited differential diagnoses, in combination with clinical and other imaging findings. They are related to prior hemorrhage, and cannot be considered indicative of malignancy. Personal Information Thank you for taking a minute to read our e-poster. If you have any question just contact me. Lourdes Figueroa Nasra Department of Radiology. Hospital Universitario La Paz. Paseo de la Castellana, Madrid, Spain lourdesfi@hotmail.com References Alyas F, et al. Eur Radiol 2008 Nov; 18(11): Alyas F, et al. Clin Radiol 2007 Aug; 62(8): Alyas F, et al. Eur Radiol 2007 Oct; 17(10): Hudson TM, et al. AJR Am J Roentgenol 1984 May; 142(5): Keenan S, et al. J Comput Assist Tomogr 2006 May-Jun; 30(3): O'Donnell P, et al. The prevalence and diagnostic significance of fluid-fluid levels in focal lesions of bone. Skeletal Radiol 2004; 33 (6): Pennekamp W, et al. Eur Radiol 2008 Oct; 18(10): Tsai JC, et al. Radiology 1990 Jun; 175(3): Van Dyck P, et al. Eur Radiol 2006 Dec; 16(12): Page 18 of 18