Mohs Micrographic Surgery Technique

Cutaneous squamous cell carcinoma characterized by MALDI mass spectrometry imaging in combination with machine learning

Cutaneous squamous cell carcinoma (SCC) is an increasingly prevalent global health concern. Current diagnostic and surgical methods are reliable, but they require considerable resources and do not provide metabolomic insight. Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) enables detailed, spatially resolved metabolomic analysis of tissue samples. Integrated with machine learning, MALDI-MSI could yield detailed information pertaining to the metabolic alterations characteristic for SCC. These insights have the potential to enhance SCC diagnosis and therapy, improving patient outcomes while tackling the growing disease burden. This study employs MALDI-MSI data, labelled according to histology, to train a supervised machine learning model (logistic regression) for the recognition and delineation of SCC. The model, based on data acquired from discrete tumor sections (n = 25) from a mouse model of SCC, achieved a predictive accuracy of 92.3% during cross-validation on the labelled data. A pathologist unacquainted with the dataset and tasked with evaluating the predictive power of the model in the unlabelled regions, agreed with the model prediction for over 99% of the tissue areas. These findings highlight the potential value of integrating MALDI-MSI with machine learning to characterize and delineate SCC, suggesting a promising direction for the advancement of mass spectrometry techniques in the clinical diagnosis of SCC and related keratinocyte carcinomas.

Reconstruction after Mohs Surgery for Digit Melanoma: Description of Techniques and Postoperative Limb Function

Introduction

Mohs surgery and reconstruction has enabled tissue-preserving resection of cutaneous malignancies. The goal of our case series evaluation is to present reconstructive techniques and functional outcomes in patients undergoing digit-sparing treatment for primary melanoma.

Materials and Methods

A chart review was performed to identify consecutive patients undergoing Mohs surgery and reconstruction for melanoma of the digits. Quality of life (QOL) survey was performed to assess function after the procedure.

Results

Thirty-two patients (13 hand, 19 foot, Age: 65.03 +/-17.78 years) who were undergoing Mohs surgery were identified. No recurrence was identified with an average follow-up of 16.1 months (1-95 months). The average defect size was 5.79 +/-4.54 cm2. Reconstruction was performed 0-4 days after resection. The most common techniques included full-thickness skin graft (FTSG) (N = 7), collagen matrix + FTSG (N = 4), and volar advancement flap (N = 7). The reconstructive technique choice appears correlated with defect size (p = 0.0125). Neuro-QOL upper extremity survey results showed a difference that approached statistical significance between patients who underwent digit-sparing treatment (n = 7) versus direct to amputation controls (n = 5) (p = 0.072). No survey differences between digit-sparing treatment (n = 10) and amputation (n = 8) were identified in the lower extremity (p = 0.61).

Conclusion

Our results show digit-sparing treatment can confirm clear surgical margins and a trend toward improvement in upper extremity function compared with immediate amputation.

Reported Outcome Measures in Mohs Micrographic Surgery in Studies With Defined Techniques for Embedding and Processing of Tissue: A Systematic Review

BACKGROUND

Mohs micrographic surgery (MMS) is a technique that combines surgical excision and histologic evaluation to achieve higher cure rates for skin cancer than traditional surgical excision. Competing performance measures have fostered numerous histologic techniques for MMS.

OBJECTIVE

To analyze differences in primary outcomes in the published literature regarding the technique of tissue processing and embedding during the MMS process.

METHODS

A systematic review was performed of the published literature in MEDLINE, PubMed, Embase, and Cochrane library that included a description of the manipulation of tissue during the grossing and embedding steps of MMS.

RESULTS

Inclusion criteria were met by 61 articles. Of these studies, the cure/recurrence rate was assessed in 1 article (1.6%), tissue conservation was assessed in 47 (77%), time-saving was assessed in 35 (57%), cost-saving was assessed in 6 (10%), and decreased artifact were assessed in 20 (33%).

CONCLUSION

There is a lack of standardization for assessing clinical outcomes in the published literature regarding MMS process techniques. Cure is a critical outcome in studies comparing MMS processing methodologies.

Repair of Defects of the Nasal Tip After Mohs Surgery

INTRODUCTION

Mohs Micrographic Surgery (MMS) is a treatment option for high-risk facial nonmelanoma skin cancer with high cure rates. Especially on the nasal tip, the tissue sparing properties of MMS are appealing. The nasal tip is a common location of nonmelanoma skin cancer and can be a challenging anatomical structure for reconstructive surgery due to its prominent location in the face, the shortage of spare tissue, as well as the stiffness and composition of different skin types, cartilage and bone.

OBJECTIVES

The aim of the present paper is to review and demonstrate how reconstruction of the nasal tip can be done successfully to improve the care for patients undergoing MMS in this area.

METHODS

Using selected literature on the area and the surgeons experience, each method of repair are described including their individual advantages and challenges. Pictures and consent were selected from one patient who underwent each repair method and three photos are presented in this paper: one after tumor resection, one immediately after repair, and one minimum 6 months post-surgery.

RESULTS

We present eight surgical methods as well as pictures from previous surgeries.

CONCLUSIONS

The results demonstrate obtainable results using very different surgical methods and the importance of an individualized approach to repairing cutaneous defects of the nasal tip.

Tissue-Sparing Outcome of Mohs Micrographic Surgery in Squamous Cell Carcinomas

BACKGROUND

Micrographic Mohs Surgery (MMS) offers the highest cure rates and healthy skin tissue sparing effect compared with standard excision.

OBJECTIVE

To quantify the tissue-sparing properties of MMS in squamous cell carcinoma (SCC) in comparison with standard excision (SE).

METHODS

A bidirectional, descriptive study, including 94 cases of SCC, was performed, on patients with histologic diagnosis of SCC (in situ, well differentiated, moderately differentiated, and undifferentiated), that where operated with MMS between 2013 and 2018 at Hospital de Clínicas Dr. Manuel Quintela in Montevideo, Uruguay. Tumor size and defect area after MMS were measured in 2 perpendicular directions. The suspected defect area was calculated with standard excision using a 4-mm margin for low risk lesions and a 10-mm margin for high risk lesions. The primary outcome of this study was the size of the defect area post MMS compared with the calculated defect area with standard excision.

RESULTS

The median tumor size was 1,41mm², and the median defect size after MMS was 4,12mm². The median defect size calculated for standard surgical excision was 8,36mm².

LIMITATIONS

We do not use all National Comprehensive Cancer Network (NCCN) criteria. We define low and high risk lesions just taking into account anatomical location, size, histopathology and whether it was a primary or recurrent tumor.

CONCLUSION

Our results show that MMS has a tissue-sparing effect of at least 52% compared to SE.

Horizontal histological sections in the preliminary evaluation of basal cell carcinoma submitted to Mohs micrographic surgery

BACKGROUND

Mohs micrographic surgery is a surgical technique for the treatment of nonmelanoma skin cancer. Surgery begins by removing the visible tumor before excision of the tissue specimens for evaluation of the tumor margins.

OBJECTIVES

To present a new way to evaluate the material obtained from debulking, by horizontal histological analysis of the fragment.

METHODS

Descriptive retrospective cross-sectional study based on the medical records and histological lamellae of patients with primary basal cell carcinomas smaller than 1.5cm submitted to Mohs micrographic surgery and who had the visible tumor analyzed by horizontal histological sections.

RESULTS

The sample evaluated included 16 patients with lesions located on the face. Comparing the histopathological examinations of incisional biopsy in vertical sections and debulking in horizontal sections, there was agreement in seven cases. The histological analysis performed in horizontal sections allowed identification of the tumor site in 13 cases, and the relation between tumor and margin showed that in 11 cases, the lateral margin was compromised.

STUDY LIMITATIONS

The technique was better-applied in lesions smaller than 2cm.

CONCLUSION

Horizontal histological analysis of debulking has advantages for Mohs surgery, since it allows visualization of almost all tumor extension in the same view plane of the dermatoscopy, allowing better definition of the histological subtype, tumor site, and tumor/margin of lesions less than 1.5cm.

[The role of the micrographic surgery in the management of basal cell carcinoma: experience in the Department of Dermatology, at the Hassan II University Hospital, Fes, Morocco]

Mohs micrographic surgery (MMS) is a technique allowing for intraoperative histologic assessment of surgical margin of malignant tumors. This study aims to highlight the role of MMS in the achievement of radical healing of basal cell carcinoma (BCC) in our patients. We conducted a study of 29 patients with basal cell carcinoma of the face over a period of 5 years. The median age of patients was 45.8 years (12-80). The sex-ratio M/F was 1.23. One-stage surgical procedure was sufficient to obtain complete resection in 51% of cases. Three-stage surgical procedure was needed in 14% of the cases. The mean duration of one-stage surgical procedure was 1 hour. No complications were reported in the postoperative period and sequelae were simple. The aesthetic and functional result was satisfactory. No recurrence was noted. BCC accounts for approximately 80% of all skin cancers. The decision to use MMS to treat BCC is based on three variables: the seat and the size of the tumor, its histological appearance with the identification of resection margin and its recurrent nature. MMS is currently the most effective method in the treatment of BCC and allows maximum healthy tissue preservation. It is a safe and repeatable surgical procedure based on team work and adapted to the treatment of patients with BCC who are at high risk of recidivism. The aesthetic and functional results are satisfactory. Recurrence rate at 5 years is 10 times lower than with the other methods.

Conservative thickness layers in Mohs micrographic surgery

BACKGROUND

Mohs micrographic surgery (MMS) is used to treat cutaneous malignancies in locations to maximize tissue sparing. The authors' aim is to demonstrate the utility of conservative thickness layers (CTL) in MMS and review patient and tumor characteristics and the potential anatomic locations where this technique may be most useful.

METHODS

We performed a retrospective chart review of patients with tumors treated with CTL in MMS of 339 tumors, recording patient demographics, tumor characteristics, MMS stages for clearance, repairs, complications, and follow-up.

RESULTS

A total of 339 tumors were treated with CTL. The most common site was the leg (28.6%), with 77.4% of these being female. The next most common sites were nose (24.5%), scalp (13.9%), and back (11.5%). Most tumors were cleared with one layer (269), but some required two layers (42), three layers (11), and four layers (1). A total of 264 tumors were left to granulate, while 75 of the nasal tumors had immediate dermabrasion.

CONCLUSION

In the properly selected patient and anatomic location, CTL taken as the first stage in MMS can be an effective and time-saving technique, leaving wounds in optimal condition for granulation with a low complication rate. Tissue sparing may allow for more reconstructive options.

Mohs Micrographic Surgery: Development, Technique, and Applications in Cutaneous Malignancies

Mohs micrographic surgery (MMS) is a specialized technique for treating skin malignancies that offers the highest cure rate by allowing histological evaluation of the entire peripheral and deep margins. MMS also maximally preserves as much uninvolved, normal adjacent tissue as possible, allowing for the best cosmetic and functional outcomes. When used for appropriate indications, this technique is also more cost-effective than other treatment modalities. In this article, the authors will discuss the development of MMS, the steps involved in this procedure, and the indications for this technique. They will also review the use of MMS for basal cell carcinoma, squamous cell carcinoma, melanoma in situ, and some less common skin malignancies.

[Mohs micrographic surgery: 27 year experience in the Northeast of Mexico]

INTRODUCTION

Skin cancer treatment includes surgical and non-surgical techniques. Among surgical techniques, Mohs micrographic surgery permits a complete evaluation of surgical margins with maximal tissue sparing.

MATERIAL AND METHODS

Retrospective review of dermatology database of skin cancer cases treated with Mohs surgery at University Hospital Dr. José Eleuterio González from 1988 to 2015.

RESULTS

A total of 546 cases were included, of these 289 (52.93%) corresponded to women and 257 (47.07%) to men. Mean age at presentation was 64.3. Most tumors (63.2%) corresponded to infiltrative basal cell carcinoma and the majority were located on the nose and cheek; 9.7% of cases corresponded to recurrent tumors. A mean of 1 Mohs stages was used in 56%, with a mean of 2 sections in 23.6%. Cutaneous flaps were used in 47.7%, representing the predominant reconstruction technique.

CONCLUSION

Mohs surgery has emerged in one of the dermatology reference centres in the North of the country as one of the surgical techniques for the treatment of aggressive carcinomas with high risk of recurrence.

On the horizon: Optical imaging for cutaneous squamous cell carcinoma

BACKGROUND

Surgical resection with negative margins remains the standard of care for high-risk cutaneous squamous cell carcinoma (SCC). However, surgical management is often limited by poor intraoperative tumor visualization and inability to detect occult nodal metastasis. The inability to intraoperatively detect microscopic disease can lead to additional surgery, tumor recurrence, and decreased survival.

METHODS

A comprehensive literature review was conducted to identify studies incorporating optical imaging technology in the management of cutaneous SCC (January 1, 2000-December 1, 2014).

RESULTS

Several innovative optical imaging techniques, Raman spectroscopy, confocal microscopy, and fluorescence imaging, have been developed for intraoperative surgical guidance. Fifty-seven studies review the ability of these techniques to improve cutaneous SCC localization at the gross and microscopic level.

CONCLUSION

Significant advances have been achieved with real-time optical imaging strategies for intraoperative cutaneous SCC margin assessment and tumor detection. Optical imaging holds promise in improving the percentage of negative surgical margins and in the early detection of micrometastatic disease. © 2015 Wiley Periodicals, Inc. Head Neck 38: E2204-E2213, 2016.

Nonmelanoma skin cancer of the head and neck: surgical treatment

This article focuses on the surgical treatment of nonmelanoma skin cancers of the head and neck. The risk factors of nonmelanoma skin cancers for recurrence and metastases that are important for choosing the best treatment option are summarized. Surgical treatment options including surgical excision with standard margins, frozen section, staged surgery, and Mohs micrographic surgery are described. Indications, techniques, outcomes, and advantages and disadvantages of each approach are reviewed. Finally, management of incomplete excisions is discussed.