Thomas J. Knackstedt

Antiseptic use in Mohs and reconstructive surgery: an American College of Mohs Surgery member survey.

It is important to highlight that a certain amount of error naturally exists with UV exposure. Solar UV exposure can depend on many factors including altitude, latitude, cloud cover, time of day, season, and individual traits of an exposed person (i.e., skin type, ethnicity, age, exposure history, clothing, etc.). One limitation in this study is that the least-squares regression model does not take into account cloud cover, variation in seasons, and latitude.

Sebaceous Carcinoma: A Review of the Scientific Literature

Opinion statementSebaceous carcinoma is a rare and potentially aggressive cutaneous malignancy. Commonly reported in the periocular area and the head and neck region, sebaceous carcinoma can arise from any sebaceous gland in the skin. The clinical presentation may be nonspecific, and a biopsy is important to establish a diagnosis and to differentiate from mimickers including benign sebaceous neoplasms, other adnexal tumors, and basal cell carcinoma. A diagnosis of Muir Torre syndrome should be considered in patients presenting with a sebaceous neoplasm. Early treatment is important given the potential of sebaceous carcinoma to spread to the regional lymph nodes and beyond. Sentinel lymph node biopsy and imaging to complete tumor staging may be indicated for larger or more aggressive tumors. Surgery, including Mohs micrographic surgery, remains the primary treatment modality for sebaceous carcinoma. Mohs micrographic surgery has the advantage of complete margin evaluation and low recurrence rates. Advanced cases may be treated with orbital exenteration, radiation therapy, chemotherapy, or combination therapy.

Birhombic Transposition Flap for Repair of Surgical Defects on the Nasal Dorsum.

Nasal dorsum defects are frequently encountered yet present specific challenges for the reconstructive surgeon. Small wounds may be left to heal by second intention. Linear closures, especially when lengthened to a 4 or 5 to one length to width ratio, offer superior healing and scar lines but are oftentimes limited by insufficient tissue laxity. A central Burow’s wedge graft may overcome this limitation. Full thickness skin grafts represent a viable option in the appropriate patient. Although a less significant issue on the nasal dorsum in contrast to the convex tip and alar subunits, the risk for poor texture or color match and insufficient volume and contour restoration with full thickness skin grafts remains. Local tissue flaps recruit adjacent tissue and reliably match the color, degree of photodamage, and sebaceous qualities of an individual’s nose. Numerous local random pattern flaps may be considered for defects on the nasal dorsum, including advancement flaps (traditional or based on a nasalis sling), rotation flaps such as the dorsal nasal flap and Peng flap, or transposition flaps such as the bilobed flap. The anchor flap is a previously described flap that uses rotation and advancement similar to a T-plasty rather than transposition to repair similar defects of the nasal tip and dorsum.

Recovery After Matrix Shave Biopsy.

Biopsy of longitudinal melanonychia remains the gold standard for diagnosis of most cases of nail melanoma. While multiple techniques have been advocated, the matrix shave (alternatively termed tangential excision) is increasingly recognizedasafirst-line surgicalapproach. Tangential matrix shave biopsy facilitates excisional sampling of nail matrix tissue (as opposed to many cases of matrix punch biopsy), the result of which allows for conclusive histologic interpretation. The procedure creates a partial thickness wound, which carries several advantages, including minimal scar/postoperative dystrophy, ease of any subsequent surgical procedure performed in the region, and potentially less postoperative discomfort. To date, there have been no cases of missed diagnoses or transected melanomas. However, there are no published series showing the typical and sequential predicted healing course for this procedure. Indeed, most patients who undergo this biopsy would benefit from a photographic slideshow showing the anticipated and predicted postoperative stages of healing.

Mohs Surgery for Nail Tumors

The virtues of Mohs surgery are well established and applicable to the nail unit and periungual tissues. When compared to traditional wide excision, Mohs surgery offers definitive examination of the entire cut surgical margin while sparing uninvolved tissues. There are specific techniques that can specifically maximize efficiency and improve outcomes when utilized on nail tumors. These involve tumor extirpation without plate avulsion and selective bone excision as a part of the Mohs layers. These techniques are demonstrated with pictures and videos.

Characteristics of Nonmelanoma Skin Cancers of the Cutaneous Perioral and Vermilion Lip Treated by Mohs Micrographic Surgery

The lip and surrounding perioral region are susceptible to non‐melanoma skin cancer, but the distribution of basal cell and squamous cell carcinoma on the cutaneous and vermilion lips has not been fully elucidated.

Utilization of indocyanine green to aid in identifying sentinel lymph nodes in Merkel cell cancer

BACKGROUND Merkel cell carcinoma (MCC) is a relatively rare skin cancer with high rates of regional lymph node involvement and metastatic spread. National Comprehensive Cancer Network guidelines recommend sentinel lymph node biopsy (SLNB) for staging purposes. The goal of this study is to report our experience utilizing indocyanine green (ICG) fluorescence-based technology to aid in SLNB detection in MCC. METHODS Consecutive MCC patients who underwent SLNB with radioisotope lymphoscintigraphy, with intraoperative handheld gamma probe, and ICG-based fluorescence imaging from 2012 to 2017 were prospectively studied (Cohort A). A group of historical controls that underwent SLNB for MCC with radioisotope lymphoscintigraphy and vital blue dye (VBD) (lymphazurin or methylene blue dye) was also analyzed (Cohort B). RESULTS Twenty-four consecutive patients underwent SLNB with lymphoscintigraphy and ICG-based fluorescence and 11 controls underwent SLNB with lymphoscintigraphy and VBD. The localization rate by node with VBD was 63.6% and ICG-based fluorescence was 94.8%. For two patients, a positive sentinel lymph node (SLN) was detected only by ICG-based fluorescence and the nodes were not detected by gamma probe and one patients only positive node was identified via ICG fluorescence only. VBD or gamma probe did not identify any unique positive SLNs in either cohort B or either cohort, respectively. CONCLUSIONS In this study, we indicate that ICG-based fluorescence is not only feasible to augment SLN identification, but it has a higher node localization rate as compared to blue dye and it was able to identify positive SLNs otherwise missed by gamma probe. This study suggests the importance of utilizing two modalities to augment SLN identification and that ICG-based fluorescence may be able to identify nodes that would have been otherwise missed by gamma probe. We will continue to follow these patients and enroll more patients in this prospective study to further determine the role that ICG-based fluorescence has in identifying sentinel lymph nodes in MCC.

Aggressive digital papillary adenocarcinoma: treatment with Mohs micrographic surgery and an update of the literature

Aggressive digital papillary adenocarcinoma (ADPA) is a rare adenocarcinoma of the sweat glands.