1. The document discusses various tumors that can occur in the chest wall, dividing them into benign and malignant lesions. 2. It provides details on specific tumor types including their demographics, imaging appearance on x-ray, CT and MRI, and pathological characteristics. 3. Examples of tumors covered include lipoma, liposarcoma, hemangioma, schwannoma, neurofibroma, and malignant peripheral nerve sheath tumors among others. Imaging findings that help differentiate between benign and malignant lesions are also highlighted.

1. Dr/ ABD ALLAH NAZEER. MD.
Radiological imaging of chest wall tumor.

2. Tumors of the chest wall are varied, some of which are found most often in this
region. They can be divided into benign and malignant tumors and into those which
arise in the ribcage and those of soft tissue density.
Benign
Benign tumours include:
soft tissue
haemangioma: common
lymphangioma: common
lipoma
schwannoma
neurofibroma
ganglioneuroma
paraganglioma
skeletal (ribcage)
fibrous dysplasia: common
aneurysmal bone cyst (ABC): common
giant cell tumour (GCT)
ossifying fibromyxoid tumour
chondromyxoid fibroma
osteochondroma
mesenchymal hamartoma of chest wall: sometimes even considered a
developmental anomaly.

3. Malignant
The most common malignant lesions are metastases. Lesions include:
soft tissue
rhabdomyosarcoma: common
Ewing sarcoma: including Askin tumour (or PNET)
ganglioneuroblastoma
neuroblastoma
angiosarcoma
leiomyosarcoma
malignant fibrous histiocytoma (MFH)
malignant peripheral nerve sheath tumor
dermatofibrosarcoma protuberans
skeletal (ribcage)
chest wall metastases: common
myeloma
chondrosarcoma
osteosarcoma

5. Soft Tissue Tumor.
1) Lipoma
Most common soft-tissue tumor of the thoracic wall.
Usually > 50 years old, obese.
Composed of adipose tissue and variable quantities of non-adipose tissue.
Location: deep soft tissue.
X-ray:
* Ovoid area of low density.
CT:
* Well circumscribed, encapsulated mass.
* Area of low attenuation (usually < -50 HU).
MRI:
•Allows better characterization of worrisome features (differential diagnosis
with liposarcoma).
* Well-defined contours.
* Internally homogeneous.
* T1: hyperintense; saturates on Fat Saturated sequences.
* T2: hyperintense; saturates on T2 Fat Saturated sequences.
* Contrast enhancement: none or minimal.
* Can present thin internal septae that slightly enhance.

6. (a) T2W coronal MRI demonstrates large hyperintense mass with some thin septae. (b) T1W
sagittal and (c) T1W axial MRI display the same large posterior hyperintense lipoma (arrow).

7. Lipoma in a 42-year-old woman. Axial contrast-
enhanced CT scan at the level of the pulmonary
artery (P) shows a well-defined mass with the
same attenuation as fat in the left part of the
chest wall. Soft-tissue septa (arrows) are
clearly visible at the periphery of the mass.
Spindle cell lipoma in a 72-year-old man. Axial
gadolinium-enhanced T1-weighted (500/15) MR image
at the level of the spleen (SP) and stomach (ST) reveals a
nodule (arrow) with heterogeneous enhancement in the
subcutaneous tissues of the back. The fat component in
this tumor is hard to identify on MR images.

8. 2) Liposarcoma
Second most frequent soft-tissue tumor.
> 50 years old.
The imaging features depend on the pathological type: well-
differentiated, dedifferentiated, myxoid, pleomorphic and mixed.
50% cases: well-differentiated (Predominantly fat tissue tumor).
X-ray and CT:
* Depends on the histological type (amount of fat and solid tissue).
* Findings favouring liposarcoma over lipoma include:
heterogeneous attenuation within the mass; invasion of adjacent
structures.
MRI:
* Prominent internal septae (> 2 mm in thickness): thick and
irregular.
* Nodular non-adipose areas that variably enhance.
* Thick septae usually enhance significantly.

9. Well-differentiated liposarcoma in a 51-year-old man. (a) Axial T1-weighted MR image (550/9) of the left chest wall shows a
mass (maximum diameter, ∼7.5 cm) superficial to the rib cage. The mass is well defined but shows marginal invasion of
adjacent muscle and of the rib cage (arrowheads). Most of the tumor has high signal intensity. However, a nonfat component
(arrow) is also seen, suggesting the presence of a malignant component. (b) Axial gadolinium-enhanced fat-suppressed T1-
weighted MR image (550/9) shows diffuse streaky and nodular enhancement of the nonfat region of the tumor (arrowhead).

10. VASCULAR TUMORS
1) Hemangioma
We include benign lesions that present multiple (normal or abnormal) vessels;
can be capillary, cavernous, arteriovenous or venous.
Can present nonvascular elements (fat, smooth muscle, thrombus, fibrous
tissue, phleboliths).
Young patients.
Location: soft tissue of the chest wall.
X-ray:
* If large enough: poorly circumscribed soft-tissue mass that rarely can cause
erosion on adjacent bone.
CT:
* Soft tissue mass with heterogeneous low levels of attenuation (due to the
other mass elements present).
MRI:
* Poorly defined masses.
* T1 and T2: variable regions of high signal intensity that represents the
vascular tissue mixed with adipose content.
* Enhancement is variable.

11. (a) T2W FS axial MRI and (b) T1W axial MRI of a 56 y.o. male patient that presents with an axillary
mass over 30 years, that recently has been increasing in size. Physical examination reveals a soft
elastic pulsatile mass. Both images display a poorly circumscribed lesion, with multiple serpiginous
structures, hyperintense in T2 and hypointense in T1, suggestive of a vascular lesion.

12. Capillary hemangioma in a 34-year-old woman. (a) Axial T1-weighted MR image (600/9) of the left chest wall
shows a mass (maximum diameter, ∼12 cm) superficial to the rib cage. Arrowhead indicates high-signal-
intensity foci at the periphery of the mass, suggesting the presence of intermingled fat tissue. (b) Axial fat-
suppressed T2-weighted MR image (5000/120) shows the mass with high signal intensity and internal septa.

13. Cavernous hemangioma in a 46-year-old man. (a) Axial T1-weighted (repetition time msec/echo time msec = 600/12)
magnetic resonance (MR) image obtained with a surface coil at the level of the liver (L) shows an ill-defined soft-
tissue mass in the right chest wall. The tumor appears as an area of heterogeneous hyperintense signal relative to the
signal intensity of adjacent muscle (arrows). (b) Axial gadolinium-enhanced T1-weighted (600/12) fat-suppressed MR
image shows heterogeneous enhancement and distended vessels (arrow) in the tumor.

14. 2) Lymphangioma
Congenital lesion; presentation < 2 years old.
Location: axilla, mediastinum.
MRI:
* T1: hypointense (identical or less than muscle).
* T1 + C(Gd): Thin peripheral and septal enhancement.
* T2: Hyperintense with thin septae.
3) Angiosarcoma
Most aggressive vascular soft-tissue tumor.
Adults.
10% associated with lymphedema (post mastectomy).
Usually associated with skin thickening, subcutaneous
edema and associated soft-tissue mass.

15. Lymphangioma in a 19-year-old man. (a) Coronal gadolinium-enhanced fat-suppressed T1-weighted MR
image (600/9) of the left posterior chest wall shows a thin peripheral rim and septal enhancement
suggestive of multilocular cystic spaces. (b) Coronal fat-suppressed T2-weighted MR image (3500/80)
obtained at the same level reveals a hyperintense lesion (maximum diameter, ∼6 cm) with internal septa.

16. PNST’S
1) Schwannoma (or Neurinomas)
Tumors of peripheral nerves (intercostals, spinal nerve roots, distal brachial plexus
branches).
20 – 50 years old.
Clinical features: slow growing painless mass.
CT:
* Encapsulated lesion, slow-growing.
* Can be associated to rib erosion.
* Iso or slightly hypodense relative to muscle.
* Homogeneous enhancement of small lesion; heterogeneous in large lesions
(cystic or hemorrhagic changes).
MRI:
* T1: low signal intensity.
* T1 + C (Gd): intense enhancement (small lesions).
* T2: hyperintense.
* Degenerative/cystic or hemorrhage changes if large size.
* Occasionally it is possible to observe the nerve from which the tumor originated.
* Target sign: hypointense center.
* Fascicular sign: multiple ring structures.

17. (a) Posteroanterior chest X-ray of a 44 y.o. female patient with persistent cervicalgias. An ovoid, well
defined tumor, is located in the left superior mediastinum (arrow). (b) T2W coronal and (c) sagittal
MRI of the same patient demonstrate the highly hyperintense, well circumscribed, encapsulated mass
proven on pathology to be a schwannoma. (d) The tumor is hypointense in T1W MRI sequences.

18. Another patient with the diagnosis of schwannoma. (a) T1W with contrast (Gd) demonstrates
heterogeneous enhancement of the tumor. These represent cystic changes or hemorrhage. (b) and (c)
Sagittal T2W MRI of this patient demonstrates an hyperintense mass with some intralesional heterogeneity.

19. Schwannoma (a) Axial gadolinium-enhanced fat-suppressed T1-weighted MR image (600/9) obtained at the level of
the end of the scapula (S) shows a lesion with central enhancement (arrow) and peripheral hypoenhancement
(arrowheads). (b) Axial fat-suppressed T2-weighted MR image (5000/120) obtained at the same level shows a well-
circumscribed mass. The central portion of the mass (arrow) has heterogeneous low signal intensity, whereas the
tumor periphery (arrowheads) has high signal intensity, creating the so-called target sign. S = scapula.

20. 2) Neurofibroma
Sporadic or associated with Neurofibromatosis Type 1 (60-90%).
Patterns: localized/diffuse/plexiform.
Localized: ( Fig. 18 )
** Solitary and sporadic
** Frequently affect superficial nerves
** Small and slow-growing
Diffuse:
** 90% sporadic (not associated to NF1)
** Children and young adults
** Associated to cutaneous and subcutaneous thickening
Plexiform:
** Pathognomonic for NF1
** Early childhood
** Risk of malignant transformation
** Involve long segments of a nerve
Occasionally: cystic degeneration and/or calcification
CT:
* Non-enhanced CT: usually hypodense.
* Enhanced CT: heterogeneous enhancement.
* Calcification (25%).
MRI:
* Target like appearance: T2 hyperintense rim (stromal tissue) surrounding an hypointense center
(cellular component).
* T1: low signal mass.
* T1 + C (Gd): enhancement of the central part of the tumor.

21. (a) T2W coronal and (b) T1W sagittal MRI of a young child with neurofibromatosis type 1.
Multiple polilobulated masses are observed, that present high intensity in T2W image (a) and
low intensity in T1W image (b). The lesions resemble the classic appearance of a "bag of worms"

22. Neurofibroma in a 26-year-old man with type 1 neurofibromatosis. Coronal T2-weighted (6,000/112)
MR image of the thoracic inlet shows intraforaminal and perineural extension of a tumor (arrows)
that has a target like appearance (i.e., a center with signal intensity lower than that in the periphery).

23. 3) Ganglioneuroma
Differentiated neuronal tumors (mature ganglion cells, Schwann cells and
nerve fibers).
Children with slight female predominance.
Often large and encapsulated, slow-growing mass.
X-Ray:
* Posterior mass (paraspinal ganglioneuroma)
CT:
* Ovoid, sharply marginated paravertebral mass.
* Iso- to hypoattenuating to muscle.
* Calcification (25%).
MRI:
* T1: hypointense.
* T2: hyperintense.
* Well defined contours.
* Whorled appearance (curvilinear bands of low signal intensity).
* Slight enhancement.
* Located in paravertebral region.

24. Ganglioneuroma in an asymptomatic 57-year-old woman. (a) Axial T2-weighted
(6,000/112) MR image of the left ventricle (LV) shows curvilinear areas of low signal
intensity (arrowheads) in the tumor, which give it a septated appearance. The tumor
had a broad base and was attached to several vertebral bodies. (b) Photograph of the
cut surface of the resected specimen shows fibrous septa (arrowheads) that correspond
to the curvilinear areas of low signal intensity on the T2-weighted MR image.

25. (a) T2W and (b) T1W sagittal MRI of a 6 y.o. patient presenting a relatively large, paravertebral mass,
hyperintense in T2 and hypointense in T1, confirmed on pathology to be a ganglioneuroma.

26. 4) Malignant PNST
Soft tissue sarcoma.
Associated to NF1 25-70%.
Can arise from a neurofibroma or schwannoma.
Affect medium-large size nerves.
20 – 50 years old.
MRI:
* T1: Iso- to hyperintense.
* T2: heterogeneously hyperintense.
Signs that favor a malignant PNST over a benign neurogenic tumor:
* Size > 5 cm;
* Absence of target or fascicular sign;
* Ill-defined margin;
* Rapid interval growth.

27. Malignant PNST on a 58 y.o. male patient. A posterior, paravertebral, round, solid tumor, isodense to
adjacent skeletal muscle, with ill-defined borders with the thoracic wall and invasion of soft tissues
and the adjacent rib is seen (arrow) on chest CT (axial plane, mediastinal window). The imaging
findings are nonspecific and required biopsy. The patient was submitted to "en bloc" resection of the
tumoral mass and 3 ribs; the histology of the surgical piece revealed a malignant high grade PNST.

28. Malignant PNST in a 43-year-old woman who was referred for management of a large mass (maximum diameter,
∼13 cm) at the neck wall that had grown through the upper chest wall. Coronal T2-weighted MR image (4000/80)
obtained at the level of the thoracic inlet reveals a dumbbell-shaped mass with heterogeneous signal intensity.

29. FIBROBLASTIC-MYOFIBROBLASTIC TUMORS
1) Elastofibroma
Soft-tissue pseudotumor; fibrous tissue with fatty streaks.
4:1 female predominance; > 60 years old
Bilaterality is common
Location: infra or sub-scapular
CT:
* Poorly circumscribed masses.
* Isoattenuating to adjacent skeletal muscle.
•Fatty streaks interspersed.
•MRI:
* T1 and T2 Isointense relative to muscle, with interspersed
streaks of fat in a fascicular pattern.
* T1 + C (Gd): heterogeneous low enhancement.

30. Elastofibroma dorsi of the left postero-lateral chest wall of an elderly woman
(arrow): isodense mass (to adjacent skeletal muscles) with scattered fat streaks.

31. Bilateral elastofibroma dorsi of the posterior chest wall (dotted circles) that present as isointense poorly
circumscribed masses on T2W images (a, b) and T1W image (c) with finely interspersed fat streaks.

32. Elastofibroma in a 78-year-old woman. (a) Axial gadolinium-enhanced fat-suppressed T1-weighted MR image (550/9)
shows a crescent-shaped soft-tissue lesion with diffuse streaky enhancement (arrows) in the deep dorsal region
between the thoracic wall and the lower third of the scapula. (b) On an axial T2-weighted MR image (4500/120), the
mass (arrows) is mostly isointense relative to adjacent muscle, with interspersed streaks of hyperintense fat.

33. 2) Fibromatosis (or Desmoid Tumor)
Composed of well-differentiated fibroblasts in a
collagenous matrix.
May arise in muscle or connective tissue.
CT:
* Poorly circumscribed.
* Non-encapsulated.
* Locally aggressive, infiltrative.
* Variable attenuation.
MRI:
* T1 and T2 heterogeneous and hypointense.
* Heterogeneous enhancement.

34. Fibromatosis in a 19-year-old woman. (a) Axial gadolinium-enhanced fat-suppressed T1-weighted MR image
(650/9) obtained at the level of the clavicle shows a mass with diffuse intense but heterogeneous
enhancement (arrow) and obvious infiltration into the adjacent pectoralis major muscle (arrowhead). (b) Axial
fat-suppressed T2-weighted MR image (3500/95) obtained at the same level shows the mass (arrow) with
intermediate signal intensity. The signal voids within the mass are suggestive of fibrous collagen bands.

35. FIBROHISTIOCYTIC TUMORS
1) UPS (Undifferentiated Pleomorphic Sarcoma)
Most common malignant soft-tissue tumor in adults.
Aggressive lesions.
Various histological subtypes: storiform-pleomorphic; myxoid; inflammatory; giant cell and
angiomatoid.
Usually over 50 y.o.; slight female predilection.
Location: deep fascia or skeletal muscle.
X-ray:
* Usually a large soft-tissue mass.
CT:
* Nonspecific!
* Usually isodense to adjacent muscle.
* Heterogeneous masses with low density areas owing to hemorrhage, necrosis or myxoid
material.
* Enhancement is heterogeneous.
•Calcification is uncommon.
•MRI:
* Useful for purposes of staging.
* Relatively well circumscribed.
* Located within or adjacent to muscle.
* T1: Iso- to hypointense relative to adjacent muscle.
* Heterogeneous due to various fibrous tissue components.
* T1 + C (Gd): enhancement of solid components.
* T2: Iso- to hypointense.

36. 80 year old female patient with an exuberant dorsal mass. Contrast-enhanced (a) and non contrast (b)
chest CT demonstrate a very large dorsal mass, positioned to the right side, well encapsulated,
contacting (but not invading) the right scapula, the right posterior ribs and part of the dorsal column.
Several heterogeneous densities are appreciated on the contrast-enhanced scan (a).

37. UPS in a 58-year-old man. (a) Axial gadolinium-enhanced fat-suppressed T1-weighted MR image (550/9) obtained at the level
of the aortic arch shows a strongly enhancing mass (arrow) with a central nonenhanced region (arrowhead) that is suggestive
of necrosis. (b)Axial T2-weighted MR image (4500/120) obtained at the same level shows the mass (arrow) with nonspecific
heterogeneous signal intensity that is higher than that of adjacent muscle and lower than that of subcutaneous fat tissue.

38. BONE TUMORS
BENIGN TUMORS
1) Fibrous dysplasia
Common; represents a benign developmental anomaly of bone precursors (replacement of lamellar
bone with a mixture of osteoid, woven bone and fibrous tissue).
20 - 30 years; progresses until growth ceases; 1M : 1F.
Location: posterior arc of rib; the ribs are the most common site for the monostotic form of fibrous
dysplasia, Usually asymptomatic.
Imaging features: expansile mass usually associated with cortical thinning.
X-ray:
* Fusiform enlargement and osseous deformity.
* Cystic areas of mixed lucency/sclerosis.
* Ground-glass density (as the matrix calcifies).
•Well-circumscribed lesions.
•CT:
* Cystic or homogeneously sclerotic.
* Well-circumscribed.
* Ground-glass appearance (amorphous mineralization).
* Expansile remodelation of the bone.
* Can contain cartilage nodules.
•No periosteal reaction.
• MRI:
* T1 Iso- to hypointense
* Variable at T2.
* Frequently enhance.
* No extra-osseous mass.

39. Fibrous dysplasia in an asymptomatic 24 y.o. male: Posteroanterior and oblique chest X-ray
(respectively, left and right) demonstrating a fusiform enlargement of the rib due to a lytic
lesion. Also, 3D VRT reconstruction (inferior) depicting this benign condition (arrow).

40. Fibrous dysplasia in the same patient: detail (dotted circle) of non-contrast enhanced chest CT displays a
well circumscribed bone insuflating lesion, of mixed lucency. Also, in oblique 3D VRT reconstruction (arrow).

41. Fibrous dysplasia of bone in a 28-year-old man. (a) Axial nonenhanced CT scan at the level of the
pulmonary artery (P) shows an expansile mass (M) with areas of ground-glass attenuation in a left rib
that indicate mineralization. (b) Axial T2-weighted (5,000/120) MR image shows heterogeneous signal
intensity in the tumor (arrow). (c) Photograph of the cut surface of a resected rib specimen reveals a
dense fibrous lesion (L) that has not invaded the surrounding structures.

42. Fibrous dysplasia of a rib in a 17-year-old boy. (a) Non-contrast CT scan obtained at the level of the
second rib shows a mass with expansile remodeling of a protracted length of bone. Trabeculation is
seen at the periphery (arrowheads), but mineralization was not observed. (b) On a coronal T2-weighted
MR image (4500/120), the tumor (arrowheads) demonstrates heterogeneous signal intensity.

43. 2) Enchondroma
Second most common benign rib tumor; thought to arise in the medullary canal due to
growth of residual cartilaginous rests displaced from the growth plate.
20 – 40 years old.
75% are solitary; 25% are multiple (Ollier’s disease and Maffuci’s syndrome).
Clinical features: incidental finding or painless swelling; may present with fracture.
Location: costochondral junction.
X-ray and CT:
* Small lytic lesions.
* Calcifications (if the matrix calcifies – not all).
* Well defined lobulated margins.
* Mild endosteal scalloping (focal reabsorption of the inner margin of cortical bones,
due to slow growing medullary lesions).
* Cortex may be expanded but is usually intact.
•No periosteal reaction
•MRI:
* T1: Iso- to hypointense;
* T1 + contrast (Gd): variable enhancement peripherally or of trans lesional septae.
* T2: hyperintense (due to the high water content of hyaline cartilage), lobulated
contour. If calcifications present: focal regions of signal drop out.
* No extraosseous mass or soft-tissue edema.

44. Posteroanterior chest X-ray (a) on a 39 y.o. male demonstrated a lytic costal lesion. The subsequent
chest-CT (b, detail of coronal plane, mediastinal window) further displayed the expansile, lytic tumor.

45. Chest CT of the same patient of Fig. 3, showed multiple left-sided enchondromas. Fine calcifications (arrows)
resembling a chondroid mineralization pattern are seen in (b)(arrow)(detail of coronal plane, bone window).

46. 3) Osteochondroma
Bony protuberance that projects from the surface of the affected bone. Uncommon
as a primary chest wall tumor.
Results of displaced growth cartilage that produces lateral bone growth from the
metaphyseal region, creating an excrescence. This exostosis is covered by a
cartilaginous cap which is the source of growth.
10 – 40 years old.
Location: costochondral junction. Also: ventral side of scapula.
Can be pedunculated or sessile.
Growth ceases at skeletal maturity.
Clinical features: pain from impingement of other structures (skin, nerves).
Imaging findings: Continuity with medullary cavity of affected bone.
X-ray and CT:
* Well defined exostosis.
* Base of lesion in continuity with the medullary.
•Growth away from the epiphysis, toward the diaphysis.
•MRI:
* T1: Isointense;
* T2: hyperintense cartilage cap. The thickness of the cartilage cap is an important
indicator of malignant transformation (if exceeds 3 cm in children or 2 cm in adults)
into sarcoma.

47. Osteochondroma (arrows). Posteroanterior chest X-ray (a) and chest CT (b) (axial plane, mediastinal
window) of an obese 17 y.o., asymptomatic. The continuity of the base of the tumor with the medullary
is well depicted on the chest CT (b). The 3D VRT reconstruction (c) demonstrates the bone exostosis.

48. Osteochondroma in a 39-year-old woman. (a) Axial contrast-enhanced CT scan at the level of the left
atrium (A) shows a dense calcification (arrowhead) that projects medially from a right rib. (b)Axial T2-
weighted (6,000/112) MR image of the right side of the chest wall obtained with a surface coil shows a
cartilaginous apical cap (arrow), which has a slightly higher signal intensity than does muscle.

49. Osteochondroma of the scapula that resulted in scapulothoracic bursitis in an 18-year-old man. (a) Coronal fat-suppressed
T2-weighted MR image (5000/120) of the right posterolateral side of the chest wall reveals osteocartilaginous exostosis
(short arrow). Note the extensive scapulothoracic bursitis (long arrows) adjacent to the lesion, which was speculated to
have resulted from irritation by the osteochondroma. (b) Coronal fat-suppressed T2-weighted MR image (5000/120) shows
the lesion with a thin, hyperintense cartilage cap (arrowheads), along with scapulothoracic bursitis (arrows).

50. 3) Chondroblastoma
Rare.
10 – 20 years.
Location: ribs (costovertebral or costochondral junction) or scapulae.
Clinical features: joint swelling or tenderness.
X-ray and CT:
* Well defined lytic lesion.
* Smooth or lobulated margins.
* Thin sclerotic margin.
* Internal calcifications can be seen in up to 40-60% of cases.
MRI:
* T1: hypointense in area of mineralization against an iso- to hypointense
background due to cartilage.
* T2: hypointense in area of mineralization against an hyperintense
background due to cartilage.
* Edema of adjacent bone and soft tissue.
* May present fluid-fluid levels due to associated aneurysmal bone cyst
change.

51. Chondromyxoid fibroma in a 56-year-old woman. (a) Axial T2-weighted (6,000/112) MR image at the level of
the liver (L) shows a mass in the lateral part of the chest wall. The mass has an overall signal intensity higher
than that of fat, but multiple septa (arrow) with lower signal intensity also are visible in the tumor.

52. 5) ABC
Very uncommon at the chest wall.
20 – 40 years old.
Can occur secondarily to another tumor (i.e. chondroblastoma, GCT).
Macroscopically: multiple blood-filled cysts lined with connective
tissue.
Clinical features: progressive or sudden pain (fracture).
X-ray and CT:
* Expansile (sometimes exuberantly) lytic lesions.
* Well defined thin sclerotic margins.
Fluid-fluid levels are characteristic (but not Pathognomonic).
MRI:
* Lobulated or septated mass (the septae may enhance with
contrast).
* Heterogeneously hyperintense in T1 and T2 due to hemorrhage.
* Fluid-fluid levels indicate hemorrhage.

53. ABC of the 9th dorsal vertebrae in a 9 y.o. child. (a) Chest CT demonstrates (arrow) an
expansile lytic lesion. (b) Sagittal and (c) coronal T2W MRI exhibiting the hyperintense
tumor (arrow) with characteristic (but not Pathognomonic) fluid-fluid levels.

54. Aneurysmal bone cyst in a 54-year-old woman. (a) Nonenhanced CT scan at the level of the clavicle
(C) shows an expansile lytic mass (M) in the medial left area of the clavicle. The mass is not well
differentiated from the overlying muscle. (b) Axial T2-weighted (6,000/112) MR image shows a mass
with overall signal intensity higher than that of fat. The mass contains regions with the signal intensity
of fluid (arrow), as well as multiple septa with low signal intensity (arrowheads).

55. Primary ABC of the scapula in an 18-year-old woman. (a) Axial fat-suppressed T2-weighted MR image (4000/99) of the scapula
shows a mass (maximum diameter, ∼6.5 cm) affecting the left chest wall and consisting of multiple cysts with fluid levels.

56. 6) GCT
Very uncommon at the chest wall.
30 – 40 years old.
Macroscopically: vascular sinuses lined with spindle and giant cells.
Location: sternum, clavicle and ribs.
X-ray and CT:
* Sharply defined border that is not sclerotic (80-85%).
* Abuts the articular surface.
* Involved cortex is thinned, expanded or deficient.
* Soft tissue mass is not infrequent.
* No matrix mineralization/calcification.
MRI:
* T1: Iso- to hypointense
* T2: Heterogeneously hyperintense but may be hypointense due to
hemosiderin or fibrosis.
* Fluid-fluid levels if ABC changes.

57. Giant cell tumor in a 54-year-old woman. (a) Sagittal T2-weighted (6,000/112) MR image of the ribs
(R) shows a mass (M) with overall signal intensity higher than that of muscle but with small foci of
low signal intensity in the periphery. (b) Photograph of a resected specimen shows extensive
vascular channels (arrows) that correspond to areas of low signal intensity on MR images.

58. GCT of a rib in a 41-year-old man. (a) Contrast-enhanced CT scan obtained at the level of the kidney (k) shows
a mass with an extraosseous portion (arrowhead) and accompanied by cortical destruction. Mineralization of
the tumor was not observed. (b) On the corresponding axial T2-weighted MR image (3500/89), the tumor is
heterogeneously dark, suggesting a fibrous component with or without chronic hemorrhage. k = kidney.

59. 7) Osteoblastoma
Rare, benign lesion.
20 – 30 y.o.; slight male predominance.
X-ray and CT:
* Predominantly lytic.
* Frequently associated to a rim of reactive sclerosis.
* Expansile lesion.
•Other findings: intralesional calcification; associated soft-tissue
mass.
MRI:
* T1: Iso- to hypointense (if calcification – areas of decreased
intensity).
* T2: Iso- to hypointense.
* “Flare phenomenon”: rim of high intensity around the soft tissue
representing edema.
* T1 + C(Gd): avid enhancement of the tumor and surrounding
tissues.

60. (a) Detail of chest X-ray of a 20 y.o. female with nonspecific posterior thoracic pain: a
predominantly exophytic, lobulated lytic rib lesion is seen. Chest CT (b) (axial plane,
mediastinal window) exhibits an heterogeneous tumor of the 4th posterior rib that pathology
confirmed to be an Osteoblastoma. (c) Also displayed on VRT reconstruction (dotted circle).

61. MALIGNANT TUMORS
1) Chondrosarcoma
Relatively frequent chest wall tumor.
> 50 years old; slight male predominance.
Location: Sternum and upper five ribs.
Variable radiographic presentation.
X-ray and CT:
* Usually a lytic lesion with intralesional calcifications – Chondroid mineralization
pattern - “arc-and-ring appearance”, flocculence or stippled shape with
predilection for periphery.
* Endosteal scalloping.
* “Moth-eaten appearance” in high-grade tumors.
* Cortical remodeling and periosteal reaction.
* Associated soft tissue mass.
•Heterogeneous contrast enhancement.
•MRI:
* T1: Hypointense in area of mineralization against an iso- to hypointense
background due to cartilage.
* T2: Hypointense in area of mineralization against an hyperintense background
due to cartilage (chondroid mineralization, high presence of water).
* Heterogeneous enhancement peripherally or in the septae.

62. Non-enhanced chest CT, mediastinal window (a, coronal plane; b, axial plane) showing a left chest wall tumor
with intralesional calcifications (arrows) and soft-tissue mass component. Note also the associated large hilar
adenopathies (b). The chest wall mass was biopsied and confirmed to be a chondrosarcoma.

63. A 59 y.o. male patient complained of thoracalgia and an anterior thoracic mass with rapid
growth (6 months). Chest CT (mediastinal window) exhibited a considerable sternal tumor,
with important cortical remodeling (a) and an associated soft tissue mass (b).

64. Chondrosarcoma in a 19-year-old woman. (a) Contrast-enhanced CT scan at the level of the left atrium
(A) shows a rib mass with chondroid mineralization (black arrowheads) and invasion of the overlying
musculature (white arrowhead). (b) Sagittal T2-weighted (6,000/112) MR image of the lateral chest
wall shows a mass arising from the rib (R), with a signal intensity higher than that of intercostal
muscle. Areas of low signal intensity (arrowheads) indicate dense mineralization in the tumor.

65. Dedifferentiated chondrosarcoma in a 66-year-old man. (a) Contrast-enhanced CT scan at the level of the pulmonary
artery (P) shows a mass with peripheral calcification (arrow) arising from the costovertebral joint and expanding into
the thoracic cavity. Note the small pleural effusion. (b) Axial T2-weighted (4,500/97.7) MR image at the level of the
pulmonary artery shows a tumor with heterogeneous high signal intensity extending into the thoracic cavity and
invading the vertebral pedicle (curved arrow). The MR image better depicts the tumor extension in the rib (straight
arrow) than does the CT scan. The pleural effusion had increased in size by the time of MR imaging.

66. 2) Myeloma
> 50 years; Male predominance
Results from monoclonal proliferation of malignant plasma cells,
which infiltrate haemopoietic locations (i.e. red marrow).
Can display as a disseminated form or as a solitary plasmacytoma.
Clinical features: progressive bone pain, anemia and renal failure.
Location: Ribs
May be necessary to use various imaging modes (bone scanning,
skeletal radiographic survey).
X-ray and CT:
* “Punched-out” lesions: multiple lytic lesions.
* May present only as diffuse osteopenia, without focal lesions.
MRI:
* T1: Iso- to Hypointense
* T2: Hyperintense
* MRI features are nonspecific!

67. 77 y.o. male with progressive lumbar pain. Sagittal T1W MRI (a) exhibits multiple hypointense lesions
distributed over the dorsal and lumbar vertebraes (arrow). Axial T2W MRI (b) partially displays an
hyperintense, well circumscribed, costal lesion confirmed to be multiple myeloma (dotted circle). (c) Chest CT
depicts a lytic lesion with soft tissue mass, also multiple myeloma. These findings are nonspecific.

68. Multiple myeloma in a 59-year-old man. Contrast-enhanced CT scan at the level of the
aortic arch (A) shows multiple osteolytic lesions involving the sternum, vertebral body,
scapulae, and ribs, and a soft-tissue mass (arrowheads) that originates from a left rib.

69. Plasmacytoma
Solitary form of multiple myeloma.
X-ray and CT:
•“Punched-out” lytic lesions with associated soft-
tissue masses.
•Erosion and/or bone destruction, creating a “soap
bubble” appearance.
• MRI:
* T2: Iso- to hyperintensity.
* Variable heterogeneous enhancement.
* Unspecific features.

70. (a) Posteroanterior chest X-ray demonstrating an extra-pleural opacity (arrow);
(b) corresponding chest CT clearly depicts a lytic rib lesion associated with an
associated large soft-tissue mass. Biopsy confirmed solitary plasmacytoma.

71. (a) Chest CT (axial plane, mediastinal window) showing a lytic costal tumor with a soft-tissue mass
component (arrow). This was a solitary lesion. (b) T2W coronal MRI in another patient with an hyperintense
mass at the upper right lateral chest wall (arrow) - also confirmed to be a solitary plasmacytoma.

72. 3) Osteosarcoma
< 20 years old.
Location: costochondral junction.
Very aggressive, with rapid growth.
The radiographic features may vary widely owing to the amount and
degree of matrix calcification: may range from blastic to totally lytic.
X-ray and CT:
* Cortical bone destruction, with “breakthrough”.
* Wide zone of transition, “moth-eaten” appearance.
* Aggressive periosteal reaction.
* Ill-defined matrix calcification.
* Soft-tissue mass associated.
MRI:
* Osteoid mineralization (occasionally purely lytic).
* Predilection for center.
* Periosteal reaction (Sunburst, Codman’s triangle).
* Hypointense in T1 and T2 in areas of mineralization.
* Soft-tissue tumor and non mineralized areas are hyperintense on T2.

73. Osteosarcoma in a 25-year-old woman. Axial gadolinium-enhanced T1-weighted (500/15) MR image
shows a large mass (M) with heterogeneous enhancement in the upper left hemithorax. The mass has
invaded the posterior chest wall (arrowheads) and filled the thoracic cavity on the left side. V = vertebra.

74. Osteosarcoma in a 39-year-old man. (a) Non-contrast CT scan obtained at the level of the liver shows a rib mass (arrow)
with central mineralization (arrowhead) near the costovertebral junction. (b) Axial T2-weighted MR image (repetition time
msec/echo time msec = 3500/98) obtained at the same level more clearly depicts the extraosseous mass (arrowhead).

75. Parosteal osteosarcoma in a 41-year-old man. (a) Contrast-enhanced CT scan obtained at the mid scapula level shows a mass (maximum
diameter, ∼7 cm) surrounding the scapula from both ventral and dorsal aspects. The mass is densely mineralized, and its mineralized
portion (arrow) crosses the medullary cavity of the scapula, a finding that suggests medullary involvement. (b) Axial T2-weighted MR
image (3200/98) obtained at the same level shows the mass (arrows) as a hypointense region, reflecting dense calcification.

76. 4) Ewing sarcoma
< 20 y.o.; 2nd most common malignant bone tumor in childhood after
osteosarcoma.
Pathology: highly undifferentiated small cells.
Presentation with local pain; less common: pathologic fracture.
Variable imagiologic presentation but with aggressive features!
X-ray:
* Poorly circumscribed lytic lesion.
* Destructive features.
* Associated large soft-tissue mass.
CT:
* Lytic lesion; less commonly: sclerotic or mixed density.
* Periosteal reaction: laminated (“onion-skin”) appearance.
* Occasionally: “Sun-burst” or “hair on end” appearances.
MRI:
* Demonstrates soft-tissue spread.
* T1 +C (GD): important but heterogeneous enhancement.
* T2: heterogeneous hyperintensity

77. 16 year-old male patient chest X-ray (inferior) and shoulder x-ray (superior) demonstrating an Ewing sarcoma
of the left clavicle: exuberant highly aggressive periosteal reaction with voluminous soft tissue component.

78. Ewing sarcoma in a 15-year-old girl. (a) Axial T1-weighted (600/12) MR image at the level of the diaphragm
(D) shows an extraosseous extra pleural mass. A focus of high signal intensity (arrow) indicates intratumoral
hemorrhage. (b) Photograph of the resected specimen reveals no bone involvement. A small focus of
hemorrhagic degeneration (arrow) corresponds to the area of high signal intensity on the MR image.

80. Thank You.