Faculty Bibliography

BACKGROUND:Perineural invasion (PNI) in cutaneous squamous cell carcinoma (SCC) is infrequent, occurring in 2.5% to 14% of patients, but it is important prognostically, because it carries an increased risk of recurrence and metastasis. Although both excision and Mohs micrographic surgery (MMS) are used to treat SCC with PNI, postoperative radiation therapy (XRT) often is recommended to minimize the risk of recurrence. To date, the effectiveness of adjuvant XRT in this setting has not been determined definitively. METHODS:The authors evaluated the effectiveness of adjuvant XRT in treating SCC with PNI by performing a thorough literature review. RESULTS:For SCC with PNI, the local control rate after MMS with or without XRT was from 92% to 100% compared with a control rate from 38% to 100% after standard excision with or without XRT. A better prognosis was associated with negative pretreatment magnetic resonance imaging or computed tomography findings than with positive radiographic evidence of PNI. Primary SCC with PNI was associated with better local control than recurrent SCC with PNI. When treatment outcomes were stratified by PNI type, SCC with microscopic PNI and SCC with extensive PNI had local control rates from 78% to 87% and from 50% to 55%, respectively. Adjuvant XRT was associated in selected patients with 100% local control. CONCLUSIONS:Few studies addressed the effectiveness of adjuvant XRT in patients who have SCC with PNI. Although XRT has been established as an adjuvant treatment for selected patients, the extent of nerve involvement by tumor, particularly in the setting of other high-risk features, may be helpful in defining its role. In the future, a multicentered, prospective, randomized clinical trial will be needed to assess the true efficacy of adjuvant XRT in the treatment of patients with SCC and PNI.

Hutchinson-Gilford progeria syndrome (HGPS, OMIM 176670) is a rare disorder characterized by accelerated aging and early death, frequently from stroke or coronary artery disease. 90% of HGPS cases carry the LMNA G608G (GGC>GGT) mutation within exon 11 of LMNA, activating a splice donor site that results in production of a dominant negative form of lamin A protein, denoted progerin. Screening 150 skin biopsies from unaffected individuals (newborn to 97 years) showed that a similar splicing event occurs in vivo at a low level in the skin at all ages. While progerin mRNA remains low, the protein accumulates in the skin with age in a subset of dermal fibroblasts and in a few terminally differentiated keratinocytes. Progerin-positive fibroblasts localize near the basement membrane and in the papillary dermis of young adult skin; however, their numbers increase and their distribution reaches the deep reticular dermis in elderly skin. Our findings demonstrate that progerin expression is a biomarker of normal cellular aging and may potentially be linked to terminal differentiation and senescence in elderly individuals.

BACKGROUND:The purpose of this study was to analyze available datasets to assess the degree of asymmetry typically associated with DFSP, and to study the optimal surgical approach for extirpating these tumors by clearing lateral margins. METHODS:MEDLINE (1994-2004) was searched for English-language multi-patient series concerning DFSP. Case series were included if complete information could be obtained for: (a) two-dimensional preoperative tumor size as measured on the skin surface before removal; (b) postoperative tumor size, as estimated by the dimensions of the final wound defect. Four case series met these criteria, and the authors were contacted directly for unpublished raw data. RESULTS:For each of 98 included tumors we computed: (1) the tumor index, a measure of clinically apparent tumor surface area; (2) clearance margin, or the theoretical best and worst-case surgical margins that would have been required for tumor clearance. We used this information to (a) assess the relationship between clinically apparent tumor size and final surgical margin; (b) determine the proportion of tumors of a given size that would be cleared by a margin of given width. We found that standard wide excision margin of 4 cm was predicted to provide a tumor clearance rate of 95% for tumors of preoperative size less than or equal to 3 cm x 3 cm. CONCLUSIONS:There is a weak relationship between preoperative tumor size and the width of the final defect after clearance. Based on our calculations, very wide local excision is necessary for clearance of most DFSPs.

A 70-year-old man presented with a birthmark on the right upper arm that had been present for as long as he could remember (Figure). His physician had referred him for a dermatology consultation because the lesion had become larger and darker over the past year. What are the next steps in the evaluation and management of this patient? The authors discuss the diagnosis and management of a changing congenital melanocytic nevus. The epidemiology and risk of transformation into melanoma are reviewed. Techniques of biopsy and indications for follow-up are discussed. A brief review of giant congenital melanocytic nevi in the newborn is also included.

Aggressive variants of basal cell carcinoma (BCC), such as infiltrating, morpheaform, and basosquamous types, are associated with invasion of underlying tissues and are often difficult to treat.1 BCCs located in embryonic fusion planes, such as the periauricular region, are thought to exhibit deep extension and, subsequently, high recurrence rates, although this theory has been challenged and remains controversial.2-4 Despite the known features of aggressive BCC, parotid gland invasion and temporal bone and facial nerve involvement are rarely reported occurrences. We describe two patients with morpheaform BCC in the periauricular region demonstrating direct invasion of the parotid gland and concomitant facial nerve involvement. These patients require complex surgical management, as highlighted in this report.

A 90-year-old Caucasian man with a history of basal cell carcinoma and squamous cell carcinoma presented with a friable erythematous nodule on his scalp that had been present for several months. The lesion measured 1.4 x 1.8 cm. What is your diagnosis? How would you proceed?

BACKGROUND:The role of curettage before Mohs micrographic surgery for basal cell carcinoma (BCC) remains controversial. Preoperative curettage may allow the surgeon to better delineate the subclinical extensions of high-risk BCCs, thereby enabling a more precise first-stage excision around tumor-containing tissue. OBJECTIVE:To assess the economic impact of preoperative curettage for high-risk BCCs treated with Mohs micrographic surgery on patients, providers, and insurers. METHODS:Given the enormous variability in practice styles, it was estimated that the time required to complete a second stage of Mohs surgery was 25, 50, or 75% of that required to complete the first stage. New York City Medicare and Standard reimbursement rates were used to approximate the cost of an additional stage of Mohs surgery for high-risk BCCs. RESULTS:Assuming that preoperative curettage increases operative efficiency by reducing the number of required Mohs stages from 2 to 1, the time saved can be quantified. Thus, if the Mohs surgeon estimates that the time required to remove a second stage is 75% of that of the first stage, the time savings with preoperative curettage equals 75% of the duration of a one-stage Mohs surgery. Similarly, when a second stage requires 50 or 25% of the time needed to complete the first stage, the time saved equals 50 or 25% of the duration of a one-stage Mohs surgery. Reducing the number of stages from 2 to 1 saves insurers and privately paying patients approximately $250 and $500, respectively. CONCLUSIONS:Whether preoperative curettage can offer a more precise first-stage excision without compromising tissue conservation remains a subject of debate. Preoperative curettage may reduce the number of Mohs surgical stages required for tumor clearance, potentially shortening patient encounters and allowing surgeons to treat additional patients, while decreasing costs for patients and insurers.