Table 4.
Summary of the paraspinal soft tissue tumours discussed in this article with their clinical signs, imaging features and incidence
| WHO | Clinical signs | US signs Method of choice for superficial tumours |
CT signs Method of choice for calcifications and bone analysis |
MRI signs Method of choice for soft tissue and bone |
Relative frequency in the back |
|---|---|---|---|---|---|
| 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 |
*Except for retroperitoneal or mediastinal masses with secondary paraspinal invasion
HU, Hounsfield unit; y, years; F, female; M, male; and WI, weighted imaging