Eileen S. Flores

Intraoperative imaging during Mohs surgery with reflectance confocal microscopy: initial clinical experience

Abstract. Mohs surgery for the removal of nonmelanoma skin cancers (NMSCs) is performed in stages, while being guided by the examination for residual tumor with frozen pathology. However, preparation of frozen pathology at each stage is time consuming and labor intensive. Real-time intraoperative reflectance confocal microscopy (RCM), combined with video mosaicking, may enable rapid detection of residual tumor directly in the surgical wounds on patients. We report our initial experience on 25 patients, using aluminum chloride for nuclear contrast. Imaging was performed in quadrants in the wound to simulate the Mohs surgeon’s examination of pathology. Images and videos of the epidermal and dermal margins were found to be of clinically acceptable quality. Bright nuclear morphology was identified at the epidermal margin and detectable in residual NMSC tumors. The presence of residual tumor and normal skin features could be detected in the peripheral and deep dermal margins. Intraoperative RCM imaging may enable detection of residual tumor directly on patients during Mohs surgery, and may serve as an adjunct for frozen pathology. Ultimately, for routine clinical utility, a stronger tumor-to-dermis contrast may be necessary, and also a smaller microscope with an automated approach for imaging in the entire wound in a rapid and controlled manner.

Video-mosaicing of reflectance confocal images for examination of extended areas of skin in vivo

With cellular-level resolution comparable to histology, reflectance confocal microscopy (RCM) imaging is a promising approach both for diagnosis of skin cancer in vivo with high sensitivity and specificity1,2, and for pre- and intra-operative detection of cancer margins to guide treatment.3–5 However, RCM images are limited to a field of view (FOV) of 1 mm -by- 1 mm, much smaller than the typical size of skin lesions. Many diagnostic features cannot be reliably identified in such small FOVs. Moreover, clinicians rely heavily on visual context of the surrounding tissue to perform diagnoses. Thus, larger areas must be imaged to evaluate cellular and morphologic features with high accuracy and repeatability. To address this concern, mosaicing approaches, which increase the FOV by acquiring a matrix of adjacent images and stitching them together to display a large area, have been developed for confocal microscopy6. In standard mosaicing, images are acquired while mechanically translating the microscope lens relative to the skin along pre-determined linear (straight-line) trajectories. This approach was implemented in the RCM scanner used in the cited studies1–5, and, in fact, is now routinely used on patients. However, the mechanics of translation limit speed and coverage to pre-selected small rectangular-shaped areas, currently up to 8 mm-by-8 mm, imaged in ~4.5 minutes. Coverage and speed could be increased, of course, with larger and faster mechanical translation systems, but would add significant size and cost to RCM scanners, and would certainly not be practical for routine use on patients. Miniaturized confocal endoscopes have been developed that allow the operator flexible control for imaging in vivo, without the constraints of mechanical translation7,8 Similar flexibility is now possible for imaging skin with the recent advent of smaller and miniaturized handheld confocal microscopes9,10,11. The operator manually moves the microscope along a desired curvilinear trajectory, with the lens gently pressed against the tissue, while acquiring a video sequence of images. Video microscopy enables the operator to choose the trajectory in real-time, allowing adaptive coverage of areas that can be selected in real-time during acquisition. Thus, an area with any shape and size may be rapidly imaged, without the previous constraints of straight-line trajectories and rectangular coverage. However, observing a video, by itself, merely as a time-sequence of small FOVs, does not readily provide the necessary visual context from the surrounding tissue. In this paper, we present results from an approach for computationally transforming such videos into mosaics that display the entire imaged area. Algorithms for video-mosaicing have been developed in the fields of computational photography and computer vision12, and their use has previously been reported for confocal endoscopic imaging7,8.We report here application of video-mosaicing to reflectance confocal images of human skin lesions and margins in vivo.

Variation in dermoscopic features of basal cell carcinoma as a function of anatomical location and pigmentation status

DEAR EDITOR, Detecting basal cell carcinomas (BCCs) early and at relatively small sizes may expand therapeutic choices and enable less invasive treatment options. To this end, dermoscopy is a useful tool to diagnose BCC at early stages with high sensitivity and specificity. Superficial BCCs have been shown to be independently associated with location on the trunk and extremities and nodular BCCs have been independently associated with a head/neck location. Few studies have evaluated dermoscopic variation in BCC morphology as a function of anatomical location and pigmentation status. Herein, we evaluate BCC dermoscopic morphology based on pigmentation status and anatomical location. We conducted a retrospective analysis of patient demographics and dermoscopic and clinical features of consecutive histopathologically proven BCCs that had been biopsied between 1 December 2007 and 1 March 2014 at the Pigmented Lesion Clinic of Skin and Cancer Associates, Plantation, FL, U.S.A. Collision and recurrent tumours, and cases with poor image quality were excluded. Clinical and dermoscopic images were taken in vivo with a Nikon Coolpix 4500 camera Nikon USA, Inc., Melville, NY, U.S.A. and DermLite II Pro HR and DermLite II Fluid dermoscopes, 3Gen Inc., San Juan Capistrano, CA, U.S.A. at 910 magnification. Dermoscopic images were routinely taken via nonpolarized and polarized contact and noncontact dermoscopy. Each lesion was classified by anatomical site as: head/neck, upper extremities (UE), trunk, and lower extremities (LE). Lesions were assessed for pigmentation and for the presence/absence of dermoscopic features. Of 479 consecutively biopsied BCCs evaluated, 392 histopathologically proven BCCs on 348 unique patients were included in the study (87 BCCs were excluded because of poor image quality). Tumours were on the head/neck for 169 (43%) lesions, trunk for 129 (33%), LE for 54 (14%) and UE for 40 (10%). The average patient age was 64 9 years (range 50 0–79 8). Pigmented lesions varied significantly across anatomical sites, with the highest frequency on the UEs (65 0%) and lowest frequency on the head/neck (49 1%). Compared with other anatomical sites (head/neck, UE and trunk) combined, BCCs on the LEs had a higher frequency of polymorphous vessels (74% vs. 44%), thin serpentine vessels (81% vs. 63%), shiny white blotches (85% vs. 46%), long white strands (76% vs. 45%), erythema (87% vs. 59%) and erosions/ulcers (69% vs. 35%) (P ≤ 0 01 for all comparisons). BCCs on the LE had the lowest frequency of arborizing vessels (24% vs. 78%) (P ≤ 0 0001) when compared with all anatomical sites. Overall, while 264 lesions contained arborizing vessels, 84 contained additional vessel morphologies resulting in the polymorphous attribute. Clinically, 35 2% BCCs were pigmented, and 57 7% were pigmented under dermoscopy. Compared with pigmented BCCs, nonpigmented BCCs were more likely to have arborizing vessels (77% vs. 59%), erythema (57% vs. 46%), shiny white blotches (48% vs. 34%) and long white strands (47% vs. 33%) (P < 0 05 for all) (Table 1). BCCs on the LE have been associated with female sex, a younger age at diagnosis, and a superficial histopathological subtype. While studies examined dermoscopic morphology of BCC of the head/neck vs. truncal location, data are limited on dermoscopic features of BCCs on the LE. In corroboration with Suppa et al., we found that BCCs of the head/neck frequently presented with arborizing vessels and BCCs on the trunk frequently presented with leaf-like structures, concentric structures, erosions/ulcers and polymorphous vessels. It is important to note that our analysis included the full spectrum of BCC histopathological subtypes (including infiltrative and morphoeiform). In addition, the present study evaluated all BCCs with nonpolarized and polarized images. By including nonpolarized and polarized images for every lesion, we characterized the full spectrum of dermoscopic features in BCC. The dermoscopic picture of BCCs on the LEs described in this study is strikingly different from those on the head/neck. Our study has established that shiny white streaks (SWS), polymorphous vessels and ulceration/erosions should raise suspicion for BCC. This is an important finding because polymorphous vessels and ulceration are features highly associated with melanoma. Our experience and the findings show that the combination of dermoscopic features of polymorphous vessels, ulcerations/erosions and SWS, identified via polarized light, can tilt the differential towards BCC, especially in LE lesions. In the present study, the BCC subtype was predominantly nodular, then infiltrative, superficial and other. The subtype distribution reflects an older population with sun-damaged skin presenting to the study clinic. Our sample size precluded us from meaningfully exploring the relationship between BCC subtype and anatomical location. Other limitations include the use of images from a single practice and a retrospective study design. Despite these limitations, we demonstrate that BCCs

Clinical Outcome and Prognosis of Young Patients with Mycosis Fungoides

Mycosis fungoides (MF) in young patients is rare and may have atypical presentations. There are limited data in these patients. The objective was to determine the clinical outcome and prognosis of young patients with MF.

Reflectance confocal microscopy features of mycosis fungoides and Sézary syndrome: correlation with histopathologic and T-cell receptor rearrangement studies.

Mycosis fungoides/Sézary syndrome (MF/SS) often requires multiple skin biopsies for definitive diagnosis. In vivo reflectance confocal microscopy (RCM) visualizes high‐resolution cellular detail of the skin. The objective of this study is to evaluate the morphologic features of MF/SS using RCM and to correlate RCM features with histopathology and T‐cell receptor (TCR) gene rearrangement studies.

Automated video-mosaicking approach for confocal microscopic imaging in vivo : an approach to address challenges in imaging living tissue and extend field of view

We describe a computer vision-based mosaicking method for in vivo videos of reflectance confocal microscopy (RCM). RCM is a microscopic imaging technique, which enables the users to rapidly examine tissue in vivo. Providing resolution at cellular-level morphology, RCM imaging combined with mosaicking has shown to be highly sensitive and specific for non-invasively guiding skin cancer diagnosis. However, current RCM mosaicking techniques with existing microscopes have been limited to two-dimensional sequences of individual still images, acquired in a highly controlled manner, and along a specific predefined raster path, covering a limited area. The recent advent of smaller handheld microscopes is enabling acquisition of videos, acquired in a relatively uncontrolled manner and along an ad-hoc arbitrarily free-form, non-rastered path. Mosaicking of video-images (video-mosaicking) is necessary to display large areas of tissue. Our video-mosaicking methods addresses this need. The method can handle unique challenges encountered during video capture such as motion blur artifacts due to rapid motion of the microscope over the imaged area, warping in frames due to changes in contact angle and varying resolution with depth. We present test examples of video-mosaics of melanoma and non-melanoma skin cancers, to demonstrate potential clinical utility.

Overview Photography and Short-term Mole Monitoring in Patients Taking a BRAF Inhibitor

Overview Photography and Short-term Mole Monitoring in Patients Taking a BRAF Inhibitor Patients taking BRAF inhibitors develop new primary melanomas and nevi. Many of these neoplasms are BRAF wild-type,1 which may be due to the paradoxical activation of the RAF/ MEK/ERK pathway via an alternative driver mutation, similar to the mechanism involved in inducing the development of squamous cell carcinomas in these patients.2 In addition, some nevi in these individuals involute,3 and many of these involuting lesions harbor a BRAFV600E (OMIM *164757) mutation. Baseline-overview photographs allow for the detection of new melanocytic lesions (MLs) and permit monitoring for morphologic changes. This study was designed to investigate the magnitude of the volatility of these MLs. We used overview photography and dermoscopy to determine the extent of melanocytic changes in patients taking a BRAF inhibitor and described their dermoscopic morphology.

Survival, disease progression and prognostic factors in elderly patients with mycosis fungoides and Sézary syndrome: a retrospective analysis of 174 patients

Advanced age at diagnosis is considered a poor prognostic factor in mycosis fungoides (MF) and Sézary syndrome (SS).

Peri-operative imaging of cancer margins with reflectance confocal microscopy during Mohs micrographic surgery: feasibility of a video-mosaicing algorithm

Reflectance confocal microscopy (RCM) imaging shows promise for guiding surgical treatment of skin cancers. Recent technological advancements such as the introduction of the handheld version of the reflectance confocal microscope, video acquisition and video-mosaicing have improved RCM as an emerging tool to evaluate cancer margins during routine surgical skin procedures such as Mohs micrographic surgery (MMS). Detection of residual non-melanoma skin cancer (NMSC) tumor during MMS is feasible, as demonstrated by the introduction of real-time perioperative imaging on patients in the surgical setting. Our study is currently testing the feasibility of a new mosaicing algorithm for perioperative RCM imaging of NMSC cancer margins on patients during MMS. We report progress toward imaging and image analysis on forty-five patients, who presented for MMS at the MSKCC Dermatology service. The first 10 patients were used as a training set to establish an RCM imaging algorithm, which was implemented on the remaining test set of 35 patients. RCM imaging, using 35% AlCl3 for nuclear contrast, was performed pre- and intra-operatively with the Vivascope 3000 (Caliber ID). Imaging was performed in quadrants in the wound, to simulate the Mohs surgeon’s examination of pathology. Videos were taken at the epidermal and deep dermal margins. Our Mohs surgeons assessed all videos and video-mosaics for quality and correlation to histology. Overall, our RCM video-mosaicing algorithm is feasible. RCM videos and video-mosaics of the epidermal and dermal margins were found to be of clinically acceptable quality. Assessment of cancer margins was affected by type of NMSC, size and location. Among the test set of 35 patients, 83% showed acceptable imaging quality, resolution and contrast. Visualization of nuclear and cellular morphology of residual BCC/SCC tumor and normal skin features could be detected in the peripheral and deep dermal margins. We observed correlation between the RCM videos/video-mosaics and the corresponding histology in 32 lesions. Peri-operative RCM imaging shows promise for improved and faster detection of cancer margins and guiding MMS in the surgical setting.

Feasibility of intraoperative imaging during Mohs surgery with reflectance confocal microscopy

Mohs surgery for the removal of non-melanoma skin cancers (NMSCs) is performed in stages, while being guided by the examination for residual tumor with frozen pathology. However, preparation of frozen pathology at each stage is timeconsuming and labor-intensive. Real-time intraoperative reflectance confocal microscopy (RCM) may enable rapid detection of residual tumor directly in surgical wounds on patients. We report initial feasibility on twenty-one patients, using 35% AlCl3 for nuclear contrast. Imaging was performed in quadrants in the wound, to simulate the Mohs surgeon’s examination of pathology. Images and videos of the epidermal and dermal margins were found to be of clinically acceptable quality. Bright nuclear morphology was identified at the epidermal margin. The presence of residual BCC/SCC tumor and normal skin features could be detected in the peripheral and deep dermal margins. Nuclear morphology was detectable in residual BCC/SCC tumors. Intraoperative RCM imaging may enable detection of residual tumor, directly on Mohs patients, and may serve as an adjunct for frozen pathology. However, a stronger source of contrast will be necessary, and also a smaller device with an automated approach for imaging in the entire wound in a rapid and controlled manner for clinical utility.