Desmoplastic squamous cell carcinoma of skin and vermilion surface: a highly malignant subtype of skin cancer.

Abstract

The prognosis of squamous cell carcinoma (SCC) of the skin is directly related to the development of metastases or local recurrence. This is affected by numerous factors, most of which are independent: clinical tumor size, histopathologic tumor thickness, depth of penetration, degree of cell differentiation, degree of keratinization, location, and immunosuppression. The determination of whether desmoplasia, previously described in only one case of SCC, constitutes an additional prognostic factor was the objective of this study. The study was performed prospectively on 594 SCCs from 509 patients. All of the factors mentioned earlier were present. Forty-four SCCs were identified by light microscopy as desmoplastic due to their prominent trabecular growth patterns, narrow columns of atypical epithelial cells, and marked desmoplastic stromal reaction, in some cases with perineural and perivascular invasion. Follow-up ranged from 4 to 10 years (median, 5.3 years). All tumors in the study patient population were treated using the paraffin section method of micrographic surgery. The 44 desmoplastic SCCs were found to metastasize 6 times more often than the remaining 550 tumors (22.7% vs. 3.8%), with 10 times as many local recurrences (27.3% vs. 2.6%). Desmoplasia is a highly significant (P < 0.001) prognostic factor for SCCs and is associated with the development of metastases or recurrence.