Cutaneous squamous cell carcinoma treated with Mohs micrographic surgery in Australia II. Perineural invasion.
BACKGROUND
Perineural invasion (PNI) is an important histologic factor that plays a significant role in cutaneous tumors' aggressiveness.


OBJECTIVE
We sought to evaluate the incidence, features, and outcomes of cutaneous squamous cell carcinoma with PNI in patients treated with Mohs micrographic surgery (MMS).


METHODS
This prospective, multicenter, case series included all patients in Australia treated with MMS for squamous cell carcinoma with PNI who were monitored by the Skin and Cancer Foundation Australia between 1993 and 2002. The parameters recorded were patient demographics, duration of tumor, site, preoperative tumor size, recurrence before MMS, histologic subtypes, postoperative defect size, and recurrence at 5 years after MMS.


RESULTS
Seventy patients were given a diagnosis of PNI. PNI was more common in men (77.1%) and in previously recurrent tumors (P = .04). The moderately and poorly differentiated histologic subtypes were more likely to be associated with PNI (P < .0001). Tumor sizes before excision, postoperative defect sizes, subclinical extension, and mean number of MMS levels were significantly larger in cases with PNI compared with cases without PNI (P < .0001, P < .0001, P = .002, and P < .0001, respectively). Most patients with PNI (52.9%) were treated with adjunctive radiotherapy. In all, 25 patients completed a 5-year follow-up post-MMS, and two of them (8.0%) were given a diagnosis of recurrence.


CONCLUSIONS
Although PNI is an uncommon feature of cutaneous squamous cell carcinoma, when present, it is associated with larger, more aggressive tumors, and the risk of recurrence is higher. This emphasizes the importance of tumor excision with margin control and long-term patient monitoring.
Leibovitch
Igal
I
Oculoplastic and Orbital Division, Department of Ophthalmology and Visual Sciences, Royal Adelaide Hospital, Adelaide, South Australia.
Huilgol
Shyamala C
SC
Selva
Dinesh
D
Hill
Dudley
D
Richards
Shawn
S
Paver
Robert
R
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001315:Australia; D002294:Carcinoma, Squamous Cell / Q000473:pathology* / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D015580:Mohs Surgery; D009361:Neoplasm Invasiveness; D010524:Peripheral Nervous System Neoplasms / Q000453:epidemiology / Q000209:etiology*; D011446:Prospective Studies; D012878:Skin Neoplasms / Q000473:pathology* / Q000601:surgery*; D013997:Time Factors