Primary intradural malignant peripheral nerve sheath tumor (MPNST) is an extremely rare diagnosis and is associated with an extremely poor prognosis. A 77-year-old man diagnosed with an intradural MPNST, more than 40 years after radiation for a testicular seminoma, is reported. Intradural MPNSTs of the spine outside the setting of neurofibromatosis is extremely rare and can masquerade as common benign nerve sheath tumors, on imaging. An older age at presentation with short duration of symptoms and prior regional radiation treatment encompassing the spine in the treatment field regardless of remoteness should alert the oncologists and neurosurgeons to the possible existence of this rare and aggressive tumor, as the management, and overall prognosis of this tumor is distinctly different compared to the usual intradural spinal tumors.
Malignant peripheral nerve sheath tumors (MPNSTs) are aggressive, locally invasive rare soft tissue sarcomas arising from peripheral nerves that originate from Schwann cells or pluripotent cells of neural crest origin [
Primary spinal malignant peripheral nerve sheath tumors (MPNST) reported in the literature.
Author & year | Age (yrs), sex | Location | Presentation | NF history | Radiation history | Extent of resection | Radiation therapy | Chemotherapy | Recurrence | Metastasis | Outcome |
---|---|---|---|---|---|---|---|---|---|---|---|
Thomeer et al., 1981 [ |
42, M | Cauda equina | Low back pain for 9 yrs with occasional L radiculopathy, impotence for 4 wks, leg weakness for 3 wks | Not specified | Total | T11-S4 2.5 Gy 4x/wk for 6 wks | Yes, 3 yrs T9-11 | No | Alive at 3 yrs | ||
Valdueza et al., 1991 [ |
40, F | Thoracic | Thoracic pain, R leg weakness | Not specified | Partial | Total 12 Gy after initial operation, total 40 Gy after spinal metastasis | No | Yes, 2 mo | Chest, pelvis, spine | Alive at 4 yrs | |
43, F | Thoracic | Low back pain for 1 mo, leg weakness for 2 wks | Not specified | Partial | Total 24 Gy after first operation, total 32 Gy after second operation for recurrence | No | Yes, 8 yrs | No | Alive at 10 yrs | ||
47, M | Cervical | Neck pain radiating to R shoulder for 9 mo, R arm weakness for 1 mo | NF1 | Not specified | Total | Total 10 Gy | No | Yes, 3 mos | Brain, lumbar | Dead at 18 mos | |
18, M | Cervical |
|
Not specified | Total | No | No | No | No | Alive at 8 mos | ||
70, F | Cervical | Neck pain radiating to R shoulder for 6 mos | Not specified | Total | No | No | No | No | Alive at 7 mos | ||
Seppälä et al., 1993 | 13, M | Lumbar | Paraparesis | NF1 | 12 yrs ago for Wilm’s tumor | Partial | Not specified | Not specified | Yes | Brain, systemic | Dead at 2 mos |
13, M | Lumbar | Paraparesis | Not specified | Total | Not specified | Not specified | Yes | Systemic | Dead at 7 mos | ||
45, F | Sacral | Not specified | NF1 | Not specified | Partial | Not specified | Not specified | Yes | Systemic | Dead at 2 mos | |
35, M | Lumbar | Radiculopathy | NF2 | Not specified | Total | Not specified | Not specified | Yes | Systemic | Dead at 18 mos | |
23, F | Thoracic | Not specified | Not specified | Total | Not specified | Not specified | Yes | Systemic | Dead at 8 mos | ||
37, F | Cervical | Radiculopathy | Not specified | Total | Yes | No | Yes, 2 yrs | Systemic | Dead at 6 yrs | ||
Celli et al., 1995 [ |
52, F | Thoracic | Pain for 8 mos, weakness | Not specified | Total | No | No | No | No | Alive at 6 yrs | |
68, F | Lumbar | Pain for 9 mos, weakness | Not specified | Total | No | No | No | No | Alive at 2 yrs | ||
43, M | Lumbar | Pain for 3 mos | Not specified | Total | No | No | No | No | Alive at 6 yrs | ||
36, F | Thoracic | Pain for 5 mos | Not specified | Total | Yes | No | Yes | No | Alive at 4 yrs | ||
22, F | Cervical | Pain for 2 yrs, weakess, incontinence | NF1 | Not specified | Total | Yes | No | Yes | Lung | Dead at 6 mos | |
30, M | Thoracic | Pain for 3 yrs, weakness | Not specified | Total | Yes | No | Yes | Lung | Dead at 14 mos | ||
West et al., 1997 [ |
40, M | Sacral | Radiculopathy | 8 yrs ago for testicular seminoma, 30.6 Gy | Total | No | No | Yes, 7 mos | No | Not specified | |
Kourea et al., 1998 [ |
11, F | Lumbar, sacral | Not specified | NF1 | Not specified | Partial | Yes | Yes | Yes, 0.5 mos | Yes, location not specified | Dead at 5 mos |
25, F | Lumbar | Not specified | NF1 | Not specified | Partial | Yes | Yes | No | No | Alive at 18 yrs | |
33, F | Lumbar | Not specified | NF1 | Not specified | Partial | No | No | No | Yes, location not specified | Dead at 2 mos | |
33, M | Lumbar | Not specified | NF1 | Not specified | Partial | Yes | Yes | Yes, 3 mos | Yes, location not specified | Dead at 22 mos | |
31, F | Lumbar | Not specified | NF1 | Not specified | partial | yes | Yes | yes, 6 mos | yes, location not specified | dead at 10 mos | |
37, F | Lumbar | Incidental | Not specified | Partial | No | Yes | Yes, 3 mos | No | Dead at 4 mos | ||
40, M | Sacral | Not specified | For testicular seminoma | Total | No | No | Yes, 9 mos | Yes, location not specified | Alive at 14 mos | ||
17, M | Thoracic | Not specified | NF1 | Not specified | Partial | No | Yes | Yes | Yes, location not specified | Dead at 11 mos | |
19, F | Thoracic | Incidental | NF1 | Not specified | Total | No | No | No | No | Alive at 35 mos | |
53, F | Thoracic | Not specified | For breast carcinoma | Partial | No | No | Yes, 6 mos | Yes, location not specified | Dead at 7 mo | ||
26, M | Thoracic | Not specified | For Hodgkin’s lymphoma | Partial | Yes | No | Yes, 13 mos | Yes, location not specified | Dead at 27 mo | ||
Acharya et al., 2001 [ |
32, M | Cauda equina | Back pain, leg weakness, bowel and bladder dysfunction | Not specified | Partial | Yes | No | No | No | Alive at 18 mos | |
Yone et al., 2004 [ |
4, M | Cauda equina | Low back pain, radiculopathy, bladder dysfunction | Not specified | Total | Yes | Yes | Yes | Brain, spine | Dead at 21 mos | |
Adamson et al., 2004 [ |
37, M | Cervical | L C6 radiculopathy | 6 yrs ago for Hodgkin’s lymphoma | Partial | Yes | No | Not specified | No | Dead after 1 yr | |
30, F | Cervical | R Horner syndrome, R C6 radiculopathy, R tricep and wrist extensor weakness | 5 yrs ago for Hodgkin’s lymphoma | Partial | No | No | Not specified | No | Dead after 1 yr | ||
Amin et al., 2004 [ |
38, M | Cauda equina | Back pain, leg weakness, bowel and bladder dysfunction | 10 yrs ago for testicular seminoma, 30 Gy/15 fractions over 3 wks | Biopsy | No | Yes, palliative | Yes, 7 mos | Not specified | Not specified | |
Albayrak et al., 2006 [ |
25, M | Thoracic | Paraparesis, bladder dysfunction | NF1 | Not specified | Total | No | No | Yes, 7 wks | Lung | Alive at 7 wks |
Chamoun et al., 2009 [ |
5, F | Cervical | Pain, gait disturbance | Not specified | Partial | Yes | Yes | Yes | Brain, thoracic and lumbar spine | Alive at 4 mos | |
Xu et al., 2012 | 8, M | Lumbar | Pain | Not specified | Total | Yes | No | Yes | Brain | Dead at 16 mos | |
Mitsuhara et al., 2013 | 47, F | Cauda equina | Back pain, R leg weakness, bowel and bladder dysfunction, altered mental status | NF2 | 15 yrs ago for uterine and cervical cancer, 22 Gy | Partial | Yes, 36 Gy brain and spine, additional 14.4 Gy to lumbosacral lesion/28 fractions | No | Not specified | No | Not specified |
Stark et al., 2013 | 56, F | Sacral | L leg radiculopathy, L foot paresis | 15 yrs ago for non-Hodgkin’s lymphoma | Not specified | No | Yes | Yes | Brainstem, spine | Dead at 24 mos | |
Wu et al., 2014 | 9, F | Thoracic, lumbar, sacral | R hip pain, bilateral leg weakness | NF2 | Not specified | Partial | No | No | Yes | Brain | Dead at 9 mos |
Li et al., 2014 | 33, F | Low thoracic, upper lumbar | Low back pain, R leg radiculopathy, hydrocephalus | Not specified | Partial | Yes, 28 Gy/19 fractions | No | Yes | Brain, diffuse spine | Dead at 29 mos | |
Lau et al., 2014 [ |
43, M | Cauda equina | Low back pain, L leg radiculopathy for 5 mos | 10 yrs ago for testicular seminoma | Total | No | Yes, alternating between ifosfamide/doxorubicin and ifosfamide/etoposide | Yes, about 60 mos | Brainstem, cervical spine, renal | Dead at 5 yrs | |
Thomas et al., 2014 | 49, M | Cauda equina | Low back pain, paraparesis | Not specified | Partial | No | No | No | Brain and spine | Not specified | |
Baharvahdat et al., 2016 | 3, F | Cervical, upper thoracic | Paraplegia, bladder and bowel dysfunction | Not specified | Partial | No | No | No | Brain and spine | Dead shortly after surgery | |
Chou et al., 2017a | 5–74 (mean 40) | 76% had adjuvant therapy | 38% over 2 yrs | 59% alive at 2 yrs | |||||||
Samancia et al., 2017 | 27, M | Cervical, upper thoracic | Hydrocephalus | Not specified | Partial | Yes | Yes | No | No | Not specified | |
Present study | 77, M | Lumbar | Left hip and buttock pain for 3 mos | About 45 yrs ago for testicular cancer | Partial | No | No | No | Intracranial leptomeningeal disease | Dead at 2 mos |
F: Female, Gy: gray, L: left, M: male, mos: months, NF1: neurofibromatosis type 1, NF2: neurofibromatosis type 2, R: right, wks: weeks, yrs: years.
a Multicenter series (
A 77-year-old man with past medical history significant for esophageal adenocarcinoma as well as testicular seminoma that was treated with conventional external bean radiation therapy (EBRT) almost 40 years back presented with three months of left hip and buttock pain in addition to left foot weakness. He had no history or clinical stigmata of neurofibromatosis.
A magnetic resonance imaging (MRI) of the lumbar spine with and without gadolinium demonstrated a homogenously enhancing, well demarcated intradural extramedullary neoplasm (Figure
(a) Magnetic resonance imaging (MRI) T1-weighted sagittal image of the lumbar spine with gadolinium demonstrates a well demarcated intradural extramedullary mass. (b) Corresponding axial image.
A partial L2 and complete L3 laminectomy was performed and a midline durotomy was made. A greyish mass was found in the intradural space arising from the left L3 nerve root with obvious enlargement and involvement of the nerve root. A frozen specimen was sent early for pathological evaluation that was diagnosed as MPNST. The nerve root of interest was clearly identified both proximally and distally, which on stimulation resulted in robust electrophysiological response suggestive of origin from a motor nerve root. No obvious plane was found between the tumor and the nerve root. Given the risk of motor deficit, the nerve root was preserved with partial resection of the tumor. Final pathology confirmed the diagnosis of MPNST (Figure
(a) Hematoxylin and eosin (H&E) staining showed high cellular density with marked pleomorphism and spindle cells arranged in fascicles (200x). (b) Immunohistochemistry was positive for SOX 10 (100x) and (c) S-100 (100x). (d) Ki-67 labeling revealed a high proliferative index (100x).
Given the initial pathologic diagnosis on frozen section, subsequent management including reoperation with extensive resection was discussed. Given his preoperative status, the patient, and family elected to observe in the short term with consideration of further treatment options following final pathology. The patient did well initially and was discharged to a skilled nursing facility. Two weeks post-operatively, however, the patient was readmitted with encephalopathy. An MRI brain with and without gadolinium demonstrated leptomeningeal metastasis (Figure
(a) Magnetic resonance imaging (MRI) T1-weighted axial image of the brain with gadolinium demonstrates leptomeningeal metastasis. (b) Corresponding sagittal image.
MPNSTs are rare entities with an incidence of 0.001%, with 20–50% of cases arising in patients with NF-1. The most common locations include the trunk, extremities, and head, and neck [
The present case developed almost four decades after being treated with EBRT for testicular seminoma, which is a significantly longer latency period as compared to other cases previously reported. Also, the imaging features were fairly characteristic of a benign intradural extramedullary neoplasm unlike a MPNST, which is typically an irregularly-bordered heterogeneously enhancing mass often with destruction of surrounding osseous structures. Similarly, the presence of leptomeningeal spread is also rare in primary intradural MPNSTs and as illustrated in this case, portends an ominous prognosis [
A rare case of an intradural MPNST diagnosed more than 40 years after radiation for a testicular seminoma is reported. Intradural MPNSTs of the spine outside the setting of neurofibromatosis are extremely rare and can masquerade common benign nerve sheath tumors on imaging. Short duration of symptoms and prior regional radiation treatment encompassing the spine in the treatment field regardless of remoteness should alert the physician to the possible existence of this rare and aggressive tumor. Being cognizant of this rare pathology can help initiate appropriate work up and evaluation, allow preoperative counselling, and alter overall surgical strategy.
Cerebral spinal fluid
Computer tomography
External bean radiation therapy
Hematoxylin and eosin
Malignant peripheral nerve sheath tumor
Magnetic resonance imaging
Neurofibromatosis type 1.
The authors declare that they have no conflicts of interest.