TY - JOUR
T1 - Imaging of non-neurogenic peripheral nerve malignancy—a case series and systematic review
AU - Luna, Rodrigo
AU - Fayad, Laura M.
AU - Rodriguez, Fausto J.
AU - Ahlawat, Shivani
N1 - Publisher Copyright:
© 2020, ISS.
PY - 2021/1
Y1 - 2021/1
N2 - Objective: To evaluate the frequency, clinico-pathologic and imaging features of malignant tumors in peripheral nerves which are of non-neurogenic origin (non-neurogenic peripheral nerve malignancy—PNM). Materials and methods: We retrospectively reviewed our pathology database for malignant peripheral nerve tumors from 07/2014–07/2019 and performed a systematic review. Exclusion criteria were malignant peripheral nerve sheath tumor (MPNST). Clinico-pathologic and imaging features, apparent diffusion coefficient (ADCmin), and standard uptake values (SUVmax) are reported. Results: After exclusion of all neurogenic tumors (benign = 196, MPNST = 57), our search yielded 19 non-neurogenic PNMs (7%, n = 19/272), due to primary intraneural malignancy (16%, n = 3/19) and secondary perineural invasion from an adjacent malignancy (16%, n = 3/19) or metastatic disease (63%, n = 12/19). Non-neurogenic PNMs were located in the lumbosacral plexus/sciatic nerves (47%, n = 9/19), brachial plexus (32%, n = 6/19), femoral nerve (5%, n = 1/19), tibial nerve (5%, n = 1/19), ulnar nerve (5%, n = 1/19), and radial nerve (5%, n = 1/19). On MRI (n = 14/19), non-neurogenic PNM tended to be small (< 5 cm, n = 10/14), isointense to muscle on T1-W (n = 14/14), hyperintense on T2-WI (n = 12/14), with enhancement (n = 12/12), low ADCmin (0.5–0.7 × 10–3 mm2/s), and variable metabolic activity (SUVmax range 2.1–13.1). A target sign was absent (n = 14/14) and fascicular sign was rarely present (n = 3/14). Systematic review revealed 89 cases of non-neurogenic PNM. Conclusion: Non-neurogenic PNMs account for 7% of PNT in our series and occur due to metastases and primary intraneural malignancy. Although non-neurogenic PNMs exhibit a non-specific MRI appearance, they lack typical signs of neurogenic tumors such as the target sign. Quantitative imaging features identified by DWI (low ADC) and F18-FDG PET/CT (high SUV) may be helpful clues to the diagnosis.
AB - Objective: To evaluate the frequency, clinico-pathologic and imaging features of malignant tumors in peripheral nerves which are of non-neurogenic origin (non-neurogenic peripheral nerve malignancy—PNM). Materials and methods: We retrospectively reviewed our pathology database for malignant peripheral nerve tumors from 07/2014–07/2019 and performed a systematic review. Exclusion criteria were malignant peripheral nerve sheath tumor (MPNST). Clinico-pathologic and imaging features, apparent diffusion coefficient (ADCmin), and standard uptake values (SUVmax) are reported. Results: After exclusion of all neurogenic tumors (benign = 196, MPNST = 57), our search yielded 19 non-neurogenic PNMs (7%, n = 19/272), due to primary intraneural malignancy (16%, n = 3/19) and secondary perineural invasion from an adjacent malignancy (16%, n = 3/19) or metastatic disease (63%, n = 12/19). Non-neurogenic PNMs were located in the lumbosacral plexus/sciatic nerves (47%, n = 9/19), brachial plexus (32%, n = 6/19), femoral nerve (5%, n = 1/19), tibial nerve (5%, n = 1/19), ulnar nerve (5%, n = 1/19), and radial nerve (5%, n = 1/19). On MRI (n = 14/19), non-neurogenic PNM tended to be small (< 5 cm, n = 10/14), isointense to muscle on T1-W (n = 14/14), hyperintense on T2-WI (n = 12/14), with enhancement (n = 12/12), low ADCmin (0.5–0.7 × 10–3 mm2/s), and variable metabolic activity (SUVmax range 2.1–13.1). A target sign was absent (n = 14/14) and fascicular sign was rarely present (n = 3/14). Systematic review revealed 89 cases of non-neurogenic PNM. Conclusion: Non-neurogenic PNMs account for 7% of PNT in our series and occur due to metastases and primary intraneural malignancy. Although non-neurogenic PNMs exhibit a non-specific MRI appearance, they lack typical signs of neurogenic tumors such as the target sign. Quantitative imaging features identified by DWI (low ADC) and F18-FDG PET/CT (high SUV) may be helpful clues to the diagnosis.
KW - Diffusion-weighted imaging
KW - F18-FDG PET/CT
KW - Malignancy
KW - Peripheral nerve
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U2 - 10.1007/s00256-020-03556-z
DO - 10.1007/s00256-020-03556-z
M3 - Article
C2 - 32699955
AN - SCOPUS:85088303418
SN - 0364-2348
VL - 50
SP - 201
EP - 215
JO - Skeletal Radiology
JF - Skeletal Radiology
IS - 1
ER -