[478] Clinicopathological & Immunohistochemical Features of Cutaneous Squamous Cell Carcinomas of the Lip

JZ Pat, RS Krause, M Raju, WH Leyva, AR Prasad. University of Arizona, Tucson, AZ; Southern Arizona VA Health Care System, Tucson, AZ; University of Washington, Seatle, WA

Background: Cutaneous squamous cell carcinoma of the lip (CSCCL) typically has an aggressive behavior compared to CSCC involving other sites. There is a paucity of data regarding the clinical and immunohistomorphologic features of these aggressive tumors especially regarding microstaging parameters.
Design: Consecutive patients with CSCCL were identified from the clinicopathologic archives. Incidence of recurrence, metastasis, Co-morbid factors and mortality were noted. Histopathologic features and immunoprofiles were studied on formalin fixed, paraffin-embedded tissue.
Results: 46 patients had excisional biopsies for CSCCL (Lower lip=37, Upper lip=9). All were Caucasian males, age range 50 to 97 years (av. 75 yrs). 45/46 patients had altered immunity: Chronic leukemia (n=8), visceral malignancy (n=8), organ transplantation (n=4), chronic renal disease (n=7), diabetes (n=9), HIV (n=1), immunosuppressive treatment (n=9). Tumor size: 0.9 to 5.2 cm (av. 3.2cm). Tumor depth: <2mm (n=11), 2-6mm (n=26), >6mm (n=9). Differentiation: 9 poor, 26 moderate, 11 well differentiated. Tumor subtypes: acantholytic (n=3), desmoplastic (n=4), spindle cell (n=2). 27 tumors invaded the deep dermis, 12 were in the underlying muscle. 4 cases had regional lymph node metastases and 6 showed local recurrences, 3 of whom died of the disease. Vascular (n=10) and perineural (n=13) invasion were seen. Average mitotic activity was >4/10 hpf. 31 tumors had infiltrative pattern of growth. Tumor showed over expression of cyclin-D1 (43/46) and p53 (44/46), and decreased E-cadherin expression (36/46). The average Ki-67 proliferative index was 89% and correlated with increased depth of invasion (p<0.001). Recurrent tumors had a higher proportion of decreased E-cadherin expression (p=0.04).
Conclusions: 1. CSCCLtend to invade into the deep dermis and beyond with the majority deeper than 2mm. 2. Most tumors have an infiltrative growth pattern, majority are moderately to poorly differentiated. 3. CSCCL show over expression of cyclin-D1 and p53, with high Ki-67 proliferative index. E-cadherin expression is decreased. 4. All of the recurrent and fatal tumors were deeper than 6mm and were not well differentiated, hence microstaging of CSCCL employing histologic grade, level of invasion, and tumor thickness, with assessment of proliferative activity may offer a more accurate assessment of tumor prognosis.
Category: Dermatopathology

Wednesday, March 11, 2009 9:30 AM

Poster Session V # 58, Wednesday Morning