Perineural spread of tumor
Updates to Article Attributes
Perineural spread of tumour is a form of local invasion in which primary tumours cells spread along the tissues of the nerve sheath. It is a well-recognised phenomenon in head and neck cancers.
Terminology
An important distinction has to be made between perineural invasion (PNI) and perineural spread (PNS). The former is a histological finding of tumour cell infiltration or associated with small nerves that cannot be radiologically imaged, while the latter is macroscopic tumour involvement along a nerve extending away from the primary tumour; this can be radiologically apparent. A third term, neurotropism, simply means that a tumour has an affinity for growth along nerves.
Pathology
Perineural tumour spread is more frequently associated with 1,2,5:
- mucosal/cutaneous squamous cell carcinoma
- oral cavity/laryngeal (2-30%) > cutaneous (3-8%)
- most common overall 5
-
salivary gland carcinoma
- adenoid cystic carcinoma (highest incidence per individual tumour 5)
- mucoepidermoid carcinoma
- mucosal/cutaneous basal cell carcinoma (2-5% demonstrate perineural tumour spread) 4
-
melanoma
- 0.8 - 2.6% demonstrate perineural spread8
- 65% are desmoplastic subtype
- 0.8 - 2.6% demonstrate perineural spread8
- lymphoma
- sarcoma
- meningioma (rare) 6
Radiographic features
MRI
Signs on MRI suggesting perineural tumour spread are:
- nerve thickening
- widening of the neural foramen
- loss of the fat surrounding the nerve
- abnormal perineural contrast enhancement
MRI can depict PNSperineural tumour spread with a sensitivity of 95%, that falls to 63% regarding the entire spread's map; the. The presence of PNSperineural tumour spread can be determined but for deducing its extent, cautious analysis and patterns of enhancement may be needed 9.
Differential diagnosis
-</ul><p>MRI can depict PNS with a sensitivity of 95%, that falls to 63% regarding the entire spread's map; the presence of PNS can be determined but for deducing its extent, cautious analysis and patterns of enhancement may be needed <sup>9</sup>. </p><h4>Differential diagnosis</h4><ul><li><a href="/articles/radiation-induced-neuritis">radiation-induced neuritis</a></li></ul>- +</ul><p>MRI can depict perineural tumour spread with a sensitivity of 95%, that falls to 63% regarding the entire spread's map. The presence of perineural tumour spread can be determined but for deducing its extent, cautious analysis and patterns of enhancement may be needed <sup>9</sup>. </p><h4>Differential diagnosis</h4><ul><li><a href="/articles/radiation-induced-neuritis">radiation-induced neuritis</a></li></ul>
References changed:
- 8. Michael Occidental, Richard Shapiro, George Jour. Lentigo maligna melanoma in situ with neurotropism. (2020) Journal of Cutaneous Pathology. 47 (12): 1155. <a href="https://doi.org/10.1111/cup.13778">doi:10.1111/cup.13778</a> <span class="ref_v4"></span>
- 8. Occidental M, Shapiro R, Jour G. Lentigo maligna melanoma in situ with neurotropism. J Cutan Pathol. 2020;47(12):1155-1158. doi:10.1111/cup.13778