Incidence of invasive squamous cell carcinomas in biopsy-proven squamous cell carcinomas in situ sent for Mohs micrographic surgery.

BACKGROUND: Squamous cell carcinoma (SCC) in situ (SCCIS) is often treated without any pathologic confirmation of tumor clearance. It is unclear how often an invasive SCC is harbored within a lesion in which the initial biopsy demonstrated SCCIS because of inadequate sampling. This study examines the final histologic diagnosis of cases in which the initial biopsies were diagnosed as SCCIS and evaluates factors that may correlate with a histologic upstaging of the diagnosis. METHODS: We prospectively recruited 29 consecutive patients with biopsy-proven SCCIS sent for Mohs micrographic surgery (MMS). Each tumor underwent MMS, and the central blocks of the Mohs debulking specimens were horizontally sectioned at 30-µm intervals until exhausted. A fellowship-trained Mohs surgeon and a board-certified dermatopathologist processed and examined these sections to determine the final histologic diagnosis of the tumor. RESULTS: Of the 29 subjects with biopsy-proven SCCIS, nine were found to harbor invasive SCC on final histology. Of the remaining lesions, seven had residual SCCIS, whereas the rest exhibited only actinic keratoses or scars. Approximately 31% of lesions showed evidence of invasive SCC. Correlating the clinical characteristics of the lesions with their corresponding final histologic diagnoses, the lesions harboring invasive SCC were more likely to demonstrate clinical signs of residual tumor (scales and papular changes) and be larger than 1.4 cm in diameter. LIMITATIONS: Our experience at a single institution in the northeastern United States may not be reflective of a wider population. There is also a possible referral bias, because only lesions with high clinical suspicion for invasive SCC were referred for MMS. CONCLUSION: Although biopsy-proven SCCIS is often treated with modalities that are best suited for superficial disease and do not involve a final pathologic confirmation of clearance (e.g., cryotherapy, electrodesiccation and curettage), this study demonstrated that up to 31% of biopsy-proven SCCIS lesions may harbor invasive SCC. Clinical signs of residual tumor and a diameter larger than 1.4 cm are statistically significant predictors of underlying invasive SCC. These data suggest that treatment modalities that include histologic control of tumor removal should also be strongly considered for the treatment of select biopsy-proven SCCIS meeting the above criteria.

A randomized, prospective trial evaluating surgeon preference in selection of absorbable suture material.

This study is the first double-blinded, randomized comparison of two absorbable sutures. To better understand product characteristics and surgeon preference, we conducted a study of two similar-appearing FDA-approved sutures, glyconate and poliglecaprone 25. Four dermatologic surgeons were enlisted. A total of 48 patients with 53 surgical sites were examined. One half of each surgical wound was closed with one type of suture and the other half with the other type. Each half was evaluated for product characteristics. There was no statistically significant difference in surgeon preference for glyconate versus poliglecaprone 25 (P=0.64). Of the cohort preferring poliglecaprone 25, there was a correlation with speed of closure (P=0.06). Of the surgeons that preferred glyconate, we found significantly better visibility (P=0.03), reduced suture breakage during knot tying (P=0.05), and correlation with better handling properties (P=0.06) associated with that preference. The data from this study will enable products to be designed towards these needs and allow surgeons to select sutures that more precisely fit their particular requirements.

Prevention of nickel allergy: the case for regulation?

Nickel is the most common allergen detected in patch-tested patients. Nickel allergy is highest among females and patients under the age of 18, affecting 35.8% of patients patch-tested in this demographic. Nickel allergic contact dermatitis is a T-cell-mediated immune reaction which most commonly presents as a skin rash in areas exposed to nickel; however, more serious reactions to nickel in medical devices and more widespread eruptions to dietary nickel can occur. In contrast to Europe, where regulations have resulted in a decreasing prevalence of nickel allergy, the incidence of nickel allergic contact dermatitis in North America is increasing. This article summarizes primary prevention strategies as well as management of patients already sensitized to nickel.