Faculty Bibliography

Importance: Confocal microscopy has the potential to provide rapid bedside pathologic analysis, but clinical adoption has been limited in part by the need for physician retraining to interpret grayscale images. Digitally stained confocal mosaics (DSCMs) mimic the colors of routine histologic specimens and may increase adaptability of this technology. Objective: To evaluate the accuracy and precision of 3 physicians using DSCMs before and after training to detect basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) in Mohs micrographic surgery fresh-tissue specimens. Design: This retrospective study used 133 DSCMs from 64 Mohs tissue excisions, which included clear margins, residual BCC, or residual SCC. Discarded tissue from Mohs surgical excisions from the dermatologic surgery units at Memorial Sloan Kettering Cancer Center and Oregon Health & Science University were collected for confocal imaging from 2006 to 2011. Final data analysis and interpretation took place between 2014 and 2016. Two Mohs surgeons and a Mohs fellow, who were blinded to the correlating gold standard frozen section diagnoses, independently reviewed the DSCMs for residual nonmelanoma skin cancer (NMSC) before and after a brief training session (about 5 minutes). The 2 assessments were separated by a 6-month washout period. Main Outcomes and Measures: Diagnostic accuracy was characterized by sensitivity and specificity of detecting NMSC using DSCMs vs standard frozen histopathologic specimens. The diagnostic precision was calculated based on interobserver agreement and kappa scores. Paired 2-sample t tests were used for comparative means analyses before and after training. Results: The average respective sensitivities and specificities of detecting NMSC were 90% (95% CI, 89%-91%) and 79% (95% CI, 52%-100%) before training and 99% (95% CI, 99%-99%) (P = .001) and 93% (95% CI, 90%-96%) (P = .18) after training; for BCC, they were 83% (95% CI, 59%-100%) and 92% (95% CI, 81%-100%) before training and 98% (95% CI, 98%-98%) (P = .18) and 97% (95% CI, 95%-100%) (P = .15) after training; for SCC, they were 73% (95% CI, 65%-81%) and 89% (95% CI, 72%-100%) before training and 100% (P = .004) and 98% (95% CI, 95%-100%) (P = .21) after training. The pretraining interobserver agreement was 72% (kappa = 0.58), and the posttraining interobserver agreement was 98% (kappa = 0.97) (P = .04). Conclusions and Relevance: Diagnostic use of DSCMs shows promising correlation to frozen histologic analysis, but image quality was affected by variations in image contrast and mosaic-stitching artifact. With training, physicians were able to read DSCMs with significantly improved accuracy and precision to detect NMSC.

BACKGROUND: While infrequent, nodal metastases in cutaneous squamous cell carcinoma (cSCC) can result in death from disease. Identification of those at risk for metastases is key to improved prognostication and treatment. OBJECTIVE: To review metastatic cSCC at the study institution. METHODS AND MATERIALS: Sixteen patients with metastatic cSCC were identified at the New York University Dermatologic Associates and Cancer Associates from 1998 to 2013. Patients were staged with American Joint Committee on Cancer (AJCC) and modified Brigham and Women's Hospital (BWH) criteria and compared to 32 control subjects. RESULTS: Seven of 16 patients were identified as Stage T2 by AJCC criteria and Stage T2b by BWH criteria; two patients were on Stage T1, three patients were on more advanced T stages, and four patients lacked primary tumor data. Five patients had hematologic malignancy, and one patient had a solid-organ transplant. CONCLUSION: The modified BWH criteria aims to better prognosticate the large group of T2 AJCC tumors, resulting in the majority of mortality. In the experience of the authors, the majority of patients with metastatic disease were on T2, stratifying to stage T2b by BWH criteria, or more advanced T stages. The findings of this study support BWH stratification of T2 tumors and also indicate that hematologic malignancy is a significant comorbidity associated with a poor outcome.

We created a line-scanning, stage scanning confocal microscope as part of a new procedure: video assisted micrographic surgery (VAMS). The need for rapid pathological assessment of the tissue on the surface of skin excisions very large since there are 3.5 million new skin cancers diagnosed annually in the United States. The new design presented here is a confocal microscope without any scanning optics. Instead, a line is focused in space and the sample, which is flattened, is physically translated such that the line scans across its face in a direction perpendicular to the line its self. The line is 6mm long and the stage is capable of scanning 50 mm, hence the field of view is quite large. The theoretical diffraction-limited resolution is 0.7um lateral and 3.7um axial. However, in this preliminary report, we present initial results that are a factor of 5-7 poorer in resolution. The results are encouraging because they demonstrate that the linear array detector measures sufficient signal from fluorescently labeled tissue and also demonstrate the large field of view achievable with VAMS.

We report a series of 20 patients who underwent inferiorly based rotation flaps for reconstruction of defects of the medial and infraorbital cheek and lower eyelid following Mohs micrographic surgery for nonmelanoma skin cancer. Defects ranged from 1.2 to 3.2 cm in longest diameter and patients ranged from 27 to 91 years of age. All 20 patients had excellent functional and cosmetic outcome with up to 2-year follow-up and no subsequent surgical or laser revision. There were no instances of partial or complete flap necrosis, hematoma, or ectropion. Our series includes defects that originated on the cheek as far laterally as directly below the lateral canthus, and terminated as far medially as the nasal sidewall. An inferiorly based rotation flap is a viable alternative to a laterally based rotation flap and should be in the armamentarium of reconstructive dermatologic and facial plastic surgeons.

Basal cell carcinoma (BCC), a malignant neoplasm derived from non-keratinizing cells that originate in the basal layer of the epidermis, is the most common cancer in humans. Several factors such as anatomic location, histologic features, primary or recurrent tumors, and patient characteristics influence the choice of treatment modality for BCC. Mohs micrographic surgery (MMS) facilitates optimal margin control and conservation of normal tissue for the management of BCC; however, other treatment modalities may also be implemented in the correct clinical scenario. Other treatment modalities that will be reviewed include simple excision, electrodesiccation and curettage, cryotherapy, topical immunotherapy and chemotherapy, photodynamic therapy, and radiation therapy. In addition, targeted molecular therapeutic options for the treatment of advanced or metastatic BCC will be discussed in this informal review based on recent literature obtained by using PubMed with relevant search terms.