Table 4 Summary of the paraspinal soft tissue tumours discussed in this article with their clinical signs, imaging features and incidence

Adipocytic tumours

Lipoma

40–60 y

Mobile

Grows with weight gain

Multiples (mostly in the back)

Hyperechoic

Fine hyperechoic lines

Compressible

HU in the negative range

Follows subcutaneous fat signal

No nodule

No septation

No enhancement

Common in upper back

Liposarcoma

40–70 y

Lipoma with atypical features:

Hypervascularity Hypoechoic areas

HU in the negative range

Calcification

Variable amount of fat content

Lipoma with atypical features: nodule/septa /enhancement

Uncommon*

Hibernoma

20–40 y

Attenuation

Flow voids

Exceptional

PNST

BPNST

30–60 y

Pain

Multiples

–

Foramen enlargement

Dumbbell shape

Split-fat sign (T1WI)

Tail sign (T1WI)

Target sign (T2WI)

Fascicular sign (T2WI)

Common

Plexiform neurofibromas

15–30 y

Consistency like a «bag of worms»

History of NF1

Superficial

Multiloculated

Cutaneous and subcutaneous Hypoechoic foci

–

Infiltrative appearance

Target sign (T2WI)

Rare

MPNST

30–60 y

Pain

Numbness

Paresthesia

NF1

–

Foramen enlargement

Bone lysis

Large size

Heterogeneous signal

Perilesional oedema

No split-fat sign

Rare

Fibro/myofibroblastic tumours

Desmoid tumour

25–45 y

F > M

Trauma

Rapidly growing

Pain

Multiples

Fascia based lesion

Hypoechoic Staghorn sign

Fascial tail sign

–

Tail sign

Band sign

Temporal change with time hypointense on all sequence

Common

Solitary fibrous tumour

40–60 y

–

Prominent feeding vessels

Prominent feeding vessels

Avid enhancement

Rare

Myxofibrosarcoma

50–70 y

–

–

Water-like appearance (T2WI)

Tail sign

Rare

Vascular tumours

Haemangioma

20–30 y

Painful

Physical exertion

Fluctuating daily size

Heterogeneous Hypoechoic with multiple cysts

Augmentation of out flow by compression

Augmentation of in flow by release

Phleboliths

Fat content (T1WI)

Serpentine vascular structures

Atrophic changes in muscles

Uncommon

Angiosarcoma

60–70 y

–

–

Heterogeneous

Vessels (high or low flow)

Foci of haemorrhages

Exceptional*

Myogenic tumours

Leiomyoma

–

–

–

–

Exceptional

Rhabdomyosarcoma

< 20 y

–

–

–

Exceptional

Leiomyosarcoma

50–70 y

–

Contiguous with a vessel

Contiguous with a vessel

Rare*

Chondro-osseous tumours

Chondro-osseous tumours

30–60 y

–

Chondroid matrix:

arc and ring-like calcifications

Bone matrix

Chondroid matrix:

High T2 signal

Exceptional

Tumours with uncertain differentiation

Myxoma

30–60 y

F > M

Fatty bright cap sign

Aligned in muscle fibre axis

–

Fluid-like signal intensity

Aligned in muscle fibre axis

Uncommon

Undifferentiated pleomorphic sarcoma

50–75 y

–

–

–

Rare

Synovial sarcoma

15–40 y

–

Calcification

Triple sign (T2WI)

Internal haemorrhage

Rare

Muscle metastasis

50–70 y

History of cancer

–

Multiple

Rim enhancement Central attenuation

Rim enhancement

Common