Squamous Cell Carcinoma In Situ Upstaged to Invasive Squamous Cell Carcinoma: A 5-Year, Single Institution Retrospective Review.

BACKGROUND: Shave biopsy may not be able to accurately distinguish squamous cell carcinoma in situ (SCCIS) from invasive squamous cell carcinoma (SCC). Information on the incidence of biopsy-proven SCCIS upstaged to SCC after a more complete histologic examination is limited. OBJECTIVE: To determine the incidence and clinical risk factors associated with upstaging the biopsy diagnosis of SCCIS into invasive SCC based on findings during Mohs micrographic surgery (MMS). METHODS: All MMS cases of SCCIS performed between March 2007 and February 2012 were identified, MMS operative notes were examined, and invasive dermal components were confirmed by the MMS slide review. Upstaged SCCIS was defined as biopsy-diagnosed SCCIS subsequently found to be an invasive SCC during MMS. RESULTS: From 566 cases with the preoperative diagnosis of SCCIS, 92 (16.3%) cases were SCCIS upstaged to SCC. Location of ears, nose, lips, and eyelids, preoperative diameter >10 mm, and biopsy report mentioning a transected base were significant predictors of upstaged SCCIS. CONCLUSION: Considering the possibility that over 16% of SCCIS may be truly invasive SCC, biopsy-proven SCCIS should be treated adequately with margin-assessed treatment modalities such as surgical excision or Mohs surgery when indicated.

Nonmelanoma Skin Cancer With Aggressive Subclinical Extension in Immunosuppressed Patients.

IMPORTANCE: Immunosuppression (IS), such as in solid-organ transplant recipients (SOTRs) and patients with human immunodeficiency virus (HIV) or hematologic malignant neoplasms, increases the risk of developing nonmelanoma skin cancers (NMSCs). However, it is unknown whether IS patients are at increased risk of developing NMSCs with aggressive subclinical extensions (NMSC-ASE), which may extend aggressively far beyond conventional surgical margins. OBJECTIVE: To study clinical characteristics of NMSC-ASE among immunocompetent (IC) and various subgroups of IS patients and to suggest a predictive model for NMSC-ASE lesions. DESIGN, SETTING, AND PARTICIPANTS: A 6-year retrospective review of 2998 NMSC cases between February 26, 2007, and February 17, 2012, at the Dermatologic and Mohs Micrographic Surgery Unit of the University of California, San Diego, Medical Center. Nonmelanoma skin cancers that required at least 3 Mohs micrographic surgery stages with final surgical margins of at least 10 mm were defined as ASE lesions. All cases were categorized into 1 of 2 groups, IS or IC. Immunosuppressed cases were further subcategorized into 3 subgroups: SOTRs and patients with HIV or hematologic malignant neoplasm. The data were analyzed in December 2012. MAIN OUTCOMES AND MEASURES: We evaluated the odds ratio of having NMSC-ASE lesions in IS patients (SOTRs, HIV, hematologic malignant neoplasm) compared with IC patients. Other clinical characteristics and preoperative risks were analyzed and compared. RESULTS: Of all 2998 cases, we identified 805 NMSC-ASE cases: 137 IS and 668 IC. Immunosuppressed patients had an odds ratio of 1.94 of having ASE lesions compared with IC patients (95% CI, 1.54-2.44; P < .001). Additionally, the SOTR subgroup was associated with a 2.74 odds of having NSMC-ASE compared with non-SOTRs (95% CI, 2.00-3.76; P < .001), and the presence of hematologic malignant neoplasm was associated with 1.74 times the odds compared with IC patients (95% CI, 1.04-2.90; P = .04). Multivariate analysis found older age (P < .001), lesion locations such as zone 1 (OR, 1.39 [95% CI, 1.04-1.85]; P = .02) or zone 2 (OR, 1.45 [95% CI, 1.08-1.94]; P = .01), and IS status (OR, 1.94 [95% CI, 1.54-2.44]; P < .001) to be significant predictors of ASE. CONCLUSIONS AND RELEVANCE: The findings of this study suggest an increased risk for NMSC-ASE lesions in IS patients, especially in SOTRs and those with hematologic malignant neoplasm, but not patients with HIV. Statistically significant predictors of NMSC-ASE lesions such as age, location, and IS status can help physicians choose the most appropriate treatment modalities and optimize surgical planning.

Mohs micrographic surgery for eccrine porocarcinoma: an update and review of the literature.

BACKGROUND: Eccrine porocarcinoma (EPC) is a rare malignancy of the eccrine sweat glands that is locally aggressive with a high propensity to metastasize. Most cases have been treated by wide local excision (WLE) with 20% local recurrence rate. There have been 20 cases of EPC treated with Mohs micrographic surgery (MMS) in the literature. OBJECTIVE: To review the literature regarding the management of this aggressive tumor using MMS. METHODS: A comprehensive literature review was conducted by searching the PubMed database using the keywords Mohs, porocarcinoma, malignant eccrine poroma, and eccrine neoplasms. RESULTS: Most of the reported cases of EPC were treated by WLE, and only 20 cases were treated with MMS. Of the 20 EPC cases treated with MMS, there was only 1 nodal recurrence and no local recurrence. Other reported treatment modalities include radiation and excision with frozen sections. The authors report the second case of EPC on the temple, and the 21st case successfully treated with MMS. CONCLUSION: Eccrine porocarcinoma is a rare neoplasm with potentially aggressive clinical behavior. In cases where tissue conservation is important, MMS should be considered.