Cutaneous head and neck basal and squamous cell carcinomas with perineural invasion
ABSTRACT Perineural invasion (PNI) occurs in 2% to 6% of cutaneous head and neck basal and squamous cell carcinomas (SCCs) and is associated with mid-face location, recurrent tumors, high histologic grade, and increasing tumor size. Patients may be asymptomatic with PNI appreciated on pathologic examination of the surgical specimen (microscopic), or may present with cranial nerve (CN) deficits (clinical). The V and VII CNs are most commonly involved. Magnetic resonance imaging (MRI) may be obtained to detect and define the extent of PNI; computed tomography (CT) or ultrasound-guided fine needle aspiration cytology (UGFNAC) may assist with detecting or excluding regional lymph node metastases. Patients with apparently resectable cancers undergo surgery, usually followed by postoperative radiotherapy (RT). Patients with unresectable cancers are treated with definitive RT. Moreover, RT may be considered if significant functional or cosmetic impairment is expected after surgical treatment. The 5-year outcomes after treatment for clinically unsuspected microscopic compared with clinical PNI are: local control, 80% and 55%; cause-specific survival, 75% and 65%; and overall survival, 55% and 50%, respectively. The incidence of grade ⩾3 complications is higher after treatment for clinical PNI versus microscopic PNI; approximately 35% compared with 15%, respectively. Proton beam RT may be used to reduce the risk of late complications by reducing RT dose to the visual apparatus and central nervous system (CNS).
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ABSTRACT: Background Nonmelanoma skin cancer (NMSC) with perineural invasion (PNI) is most commonly seen in cutaneous squamous cell carcinoma of the head and neck (SCCHN). The cranial nerves are a conduit for skin cancer to reach the brainstem. Methods The histopathological features of 51 tissue specimens from 49 patients with cutaneous SCCHN and clinical PNI were assessed with consecutive transverse and longitudinal sections. ResultsNo skip lesions were identified. Tumor spread was contiguous in all specimens. No tumor spread into the perineural space from surrounding or adjacent tumor was seen. Proximal large cranial nerves showed epineural involvement in 3.9% in areas with large tumor bulk, extensive PNI, and intraneural invasion. Conclusion Perineural tumor spread in cutaneous SCCHN was contiguous and no skip lesions were evident in nerve specimens assessed in this series. Spread beyond cranial nerve perineurium was uncommon, reflecting its multilayer barrier function at this level. These findings may have treatment implications. (c) 2013 Wiley Periodicals, Inc. Head Neck 36: 1611-1618, 2014Head & Neck 11/2014; 36(11). DOI:10.1002/hed.23509 · 2.83 Impact Factor
Article: Proton therapy for head neck cancerOral Oncology 11/2014; 51(2). DOI:10.1016/j.oraloncology.2014.10.015 · 3.03 Impact Factor
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ABSTRACT: Background Perineural invasion (PNI) is an important histologic finding and may be a negative prognostic factor for squamous cell carcinoma (SCC). It may be associated with more-aggressive tumor behavior. Mohs surgeons encounter microscopic PNI regularly and must be able to diagnose it accurately to guide care decisions.Objective To describe benign histologic mimickers of PNI and neural structures in SCC commonly encountered on frozen, hematoxylin and eosin–stained sections and to review how to differentiate them from PNI.Methods and MaterialsReview of the literature regarding histologic mimickers of PNI and additional contributions to frozen section PNI and nerve tissue mimickers.ResultsWe describe benign findings, including arrector pili muscles, eccrine muscles, vessels, granulomatous inflammation, and eddies of SCC, that may each be mistaken for nerves or PNI. We discuss the ways in which they may be distinguished on frozen sections and review other commonly encountered entities that resemble PNI.Conclusion Perineural inflammation and peritumoral fibrosis are common mimickers of PNI on frozen section, although other mimickers exist on permanent sections. Normal structures may appear “neural” by way of frozen tissue orientation, processing, or inflammation and thus must be differentiated from nerve tissue and PNI during Mohs surgery.Dermatologic Surgery 03/2014; 40(5). DOI:10.1111/dsu.12473 · 1.56 Impact Factor