Oncologic Accuracy of Image-guided Percutaneous Core-Needle Biopsy of Peripheral Nerve Sheath Tumors at a High-volume Sarcoma Center

Abstract

Objectives: Peripheral nerve sheath tumors (PNSTs) are clinically heterogenous, comprising benign (BPNST) and malignant (MPNST) variants. BPNSTs can be managed with nerve-sparing excision or observation. MPNSTs require radical resection and multidisciplinary oncologic management (1, 15). Image-guided core-needle biopsy (IGCNBx) is the well-established standard to obtain preoperative tissue diagnosis of soft tissue tumors. However, there has been resistance to performing IGCNBx of PNSTs because of the presumed risk of nerve injury and unknown accuracy in determining malignancy. We sought to define the accuracy and safety of IGCNBx in PNSTs. Materials and Methods: All patients that underwent both IGCNBx and surgical resection of a PNST at our institution between 2002 and 2016 were analyzed. The accuracy of IGCNBx in determining malignancy was calculated, including subgroup analyses by histologic subtype and neurofibromatosis 1 status. Complication data were collected and analyzed. Results: Among the 78 PNSTs with IGCNBx and postresection surgical pathology, 76% (n=59) had BPNST and 24% (n=19) had MPNST on postresection surgical pathology. IGCNBx accurately determined malignancy in 94% of cases. IGCNBx demonstrating schwannoma or MPNST were 100% accurate in determining malignancy. IGCNBx demonstrating neurofibroma or indeterminate results were 33% and 57% malignant on postresection surgical pathology, respectively. There were no long-term complications, including sensory or motor deficits, from IGCNBx. Conclusions: Percutaneous IGCNBx demonstrates 94% accuracy in differentiating benign from malignant PNSTs. IGCNBx demonstrating neurofibroma or indeterminate pathology should be interpreted with caution because of risk of malignant reclassification on surgical pathology. Our results reaffirm the safety of IGCNBx, as no patients experienced long-term complications.

Cell-free DNA ultra-low-pass whole genome sequencing to distinguish malignant peripheral nerve sheath tumor (MPNST) from its benign precursor lesion: A cross-sectional study

“…Indeed, in current practice, confirmation of MPNST identified by clinical/imaging suspicion is usually attempted by solid tumor biopsy, which can be exquisitely painful given the peripheral nerve site, is often technically difficult due to lesions’ propensity for localizing to viscera and the retroperitoneum, and is associated with serious complications including nerve palsy and dissemination of malignant tumor cells [ 53 ]. Additionally, biopsy is not without diagnostic caveat, as the development of MPNST from within PN lesions causes sampling bias with image-guided biopsies shown to result in low negative predictive value (NPV), with 50% of NF1 patients diagnosed with PN on image-guided core-needle biopsy being subsequently reclassified as MPNST following surgical resection in one retrospective study [ 19 ]. Unlike image-guided tumor biopsy, our liquid biopsy approach to measure tumor fraction reflects chromosomal instability throughout the body, thus limiting the potential for sampling bias.…”

“…Serial PN biopsies are impractical as 9% to 21% of NF1 patients will have multiple PN, with varying levels of malignant potential requiring surveillance [ 16 – 18 ]. Moreover, biopsies can yield false negative results due to geographic tumor heterogeneity resulting from MPNST arising from within heterogeneous PN precursor lesions [ 19 ]. Furthermore, standard cross-sectional imaging cannot distinguish MPNST from PN with adequate specificity [ 20 , 21 ].…”

Malignant Glandular Triton Tumor Arising in the Radial Nerve with Prolonged Survival: A Case Report and Review of the Literature

“…IGCNBx demonstrating schwannoma or MPNST were 100% accurate in determining malignancy. On the other hand, out of 12 neurofibromas diagnosed on IGCNBx, four (33%) proved to be MPNSTs on postresection surgical pathology [39]. This discrepancy is likely because of the heterogeneous nature of neurofibromas.…”

Treatment of malignant peripheral nerve sheath tumors in pediatric NF1 disease

“…Imaging plays an important role in diagnostic work-up, as biopsies are cumbersome in NF1 patients especially since they may be painful and result in persisting nerve damage [42]. Additionally, in NF1 patients, sampling errors are common [43,44]. Magnetic resonance imaging (MRI) is widely used but may be inadequate to detect and especially distinguish benign and malignant lesions [45,46].…”