Analysis of incomplete excisions of basal-cell carcinomas after breadloaf microscopy compared with 3D-microscopy: a prospective randomized and blinded study

Review on the Role of Paraffin-embedded Margin-controlled Mohs Micrographic Surgery to Treat Skin Tumors

Paraffin-embedded margin-controlled Mohs micrographic surgery (PMMS) includes various procedures such as slow Mohs or deferred Mohs technique, the Muffin and Tübingen techniques, and staged margin excision, or the spaghetti technique. PMMS is a variation of conventional Mohs micrographic surgery (MMS) that allows histopathological examination with delayed margin control. PMMS requires minimum training and may be adopted by any hospital. The setback is that PMMS can require procedures across multiple days. PMMS lowers the rate of recurrence of basal cell carcinoma vs wide local excision in high-risk basal cell carcinoma, and improves the rates of recurrence and survival in lentigo maligna. PMMS can be very useful in high-risk squamous cell carcinoma treatment. Finally, it is a promising technique to treat infrequent skin neoplasms, such as dermatofibrosarcoma protuberans, or extramammary Paget's disease, among others. In this article, we present a literature narrative review on PMMS, describing techniques and indications, and highlighting long-term outcomes.

Review on the Role of Paraffin-embedded Margin-controlled Mohs Micrographic Surgery to Treat Skin Tumors

Paraffin-embedded margin-controlled Mohs micrographic surgery (PMMS) includes various procedures such as slow Mohs or deferred Mohs technique, the Muffin and Tübingen techniques, and staged margin excision, or the spaghetti technique. PMMS is a variation of conventional Mohs micrographic surgery (MMS) that allows histopathological examination with delayed margin control. PMMS requires minimum training and may be adopted by any hospital. The setback is that PMMS can require procedures across multiple days. PMMS lowers the rate of recurrence of basal cell carcinoma vs wide local excision in high-risk basal cell carcinoma, and improves the rates of recurrence and survival in lentigo maligna. PMMS can be very useful in high-risk squamous cell carcinoma treatment. Finally, it is a promising technique to treat infrequent skin neoplasms, such as dermatofibrosarcoma protuberans, or extramammary Paget's disease, among others. In this article, we present a literature narrative review on PMMS, describing techniques and indications, and highlighting long-term outcomes.

[Micrographic controlled surgery in everyday dermatosurgery]

Micrographic controlled surgery (MCS) has become established in dermatosurgery in recent years and includes various methods to enable the histologically proven complete resection of malignant cutaneous tumors, while at the same time sparing tumor-free tissue in the immediate vicinity as much as possible. MCS is of great importance in the surgical treatment of cutaneous malignancies in so-called problem locations and aggressive tumor subtypes. Indications for MCS include basal cell carcinoma, cutaneous squamous cell carcinoma, Bowen's disease and Bowen's carcinoma, melanoma in chronic light-damaged skin with acral lentiginous melanoma, dermatofibrosarcoma protuberans (DFSP), and Merkel cell carcinoma. However, other tumor entities are also treated using MCS, such as extramammary Paget's disease and various cutaneous sarcomas. All procedures subsumed under MCS have in common the marking of the surgical specimen for topographical orientation, which provides assignment of remaining tumor remnants. Various methods of MCS (3D histology, the horizontal method or Mohs surgery) are presented in this article. Furthermore, this article aims to raise awareness of the possibilities and limitations of micrographically controlled surgery.

A review of the evidence for Mohs micrographic surgery in the treatment of basal cell carcinoma

MMS is considered the gold standard treatment for basal cell carcinoma (BCC) particularly for sites with a high-risk of incomplete excision such as the central face, tumours with an aggressive growth pattern and consequent unpredictable sub-clinical extension and recurrent tumours. However, the process is more time consuming and the magnitude of benefit is uncertain. This article aims to provide a more complete picture of current evidence, including a review of cosmetic outcomes, tissue sparing ability and cost-effectiveness of MMS. Whilst robust evidence is lacking, there is a large volume of observational data supporting a low recurrence rate after MMS. The risk of incomplete excision and higher recurrence rate of standard excision favours the use of MMS at high-risk sites. There is some low certainty evidence that MMS results in a smaller defect size than SE and that incomplete excision with SE results in larger defects. Larger defects may affect cosmetic outcome but there is no direct evidence that MMS improves cosmetic outcome compared to SE. There is conflicting evidence regarding the cost of MMS in comparison to SE with some studies recognising MMS as less expensive than SE and others more which may reflect the healthcare setting. A multi-centre 10 year RCT comparing MMS and SE in the treatment of high-risk BCC would be desirable, but is unlikely to be feasible or ethical. Collection of robust registry data capturing both MMS and SE outcomes would provide additional long-term outcomes.

Modification of Skin Flaps for Single-Stage Reconstruction of the Nasal Ala Using All-Layer Suture-A Prospective Study

BACKGROUND AND OBJECTIVES

After local flaps, it may be necessary to reconstruct the contour of the nasal ala. This is possible with a single-stage all-layer shaping suture. In the present study, the functional and aesthetic results after single-stage reconstruction of the nasal ala were prospectively evaluated.

PATIENTS AND METHODS

Patients who underwent surgery for skin tumors of the nose between 06/2019 and 06/2020 who required reconstruction of the nasal ala as part of the defect closure and had an all-layer suture used were prospectively included in the study. A standardized evaluation of aesthetic and functional outcome was conducted by the patient and a physician at discharge as well as 4 weeks later. Patients additionally underwent a follow-up survey 6 months later.

RESULTS

Thirty-seven patients were included in the study. Four weeks postoperatively, all flaps were found to be fully healed and vital. Aesthetic outcome at 4 weeks was rated as very good or good by physicians in 73% and by patients in 78.4%. Persistent complications due to reduced blood flow were not observed.

CONCLUSION

The reshaping of the nasal ala as part of the defect reconstruction with an all-layer suture demonstrates very good aesthetic as well as functional results and can be performed in a single-stage procedure. .

Local Recurrence Rates of Skin Tumors After Resection With Complete Circumferential Peripheral and Deep Margin Assessment-Identification of High-Risk Entities

BACKGROUND

The local recurrence rates of malignant skin tumors after micrographic controlled surgery using complete circumferential peripheral and deep margin assessment (CCPDMA) are reported to be low. However, in daily practice, tumor entities with a significantly higher recurrence rate are found.

OBJECTIVE

The aim of the investigation was to identify these high-risk tumors to develop approaches for risk stratification.

PATIENTS AND METHODS

We included different malignant tumors that were surgically treated and examined with CCPDMA using paraffin sections and H&E staining. Re-excisions were performed until the tumor was completely removed.

RESULTS

Ninety-nine thousand three hundred seventy-two tumors were included in the study; the follow-up period was 4 years (median). Eight tumor entities were identified as high-risk entities, showing a significantly higher local recurrence rate of over 20%: desmoplastic squamous cell carcinoma, desmoplastic melanoma, Merkel cell carcinoma, microcystic adnexal carcinoma, pleomorphic sarcoma, liposarcoma as well as angiosarcoma, and extramammary Paget's disease.

CONCLUSION

Complete circumferential peripheral and deep margin assessment allows complete control of the resection margins and enables skin-sparing resections with low recurrence rates for basal cell carcinomas, nondesmoplastic squamous cell carcinomas, lentiginous melanomas, and dermatofibrosarcoma protuberans. However, other tumors show significantly higher recurrence rates and therefore need to be classified as high-risk tumors.

Three-dimensional histology vs. serial section histology in the treatment of primary basal cell carcinoma: a randomized, prospective, blinded study of 569 tumours

BACKGROUND

For basal cell carcinoma (BCC), only few controlled data have been published so far, which directly compare micrographically controlled surgery with conventional serial section histology. In addition to Mohs surgery, which uses cryostat sections, also three-dimensional histology (3D-histology), based on paraffin sections, is available to ensure complete control of the margins and basic sections.

OBJECTIVES

To investigate the rate of local recurrence (LR) as well as the number of required re-excisions for basal cell carcinomas with serial section histology vs. 3D-histology.

METHODS

We compared serial sections histology with 3D-histology in a prospective, randomized, controlled blinded trial and analysed 569 BCC of all subtypes up to 30 mm diameter, 287 BCC in the 3D group and 282 BCC in the serial section group. Excisions were performed with adapted primary resection margin according to location and size of the tumour. Surgeons were blinded at the time of surgery as they did not know which histological method will be used. Both methods used paraffin sections.

RESULTS

Both groups did not differ regarding patients age, tumour location, tumour diameter, tumour subtypes or primary resection margins. In the serial section group, re-excisions were required in 21%; 24 tumours (8.4%) recurred after a median of 2.2 years. In the 3D-histology group, re-excisions were required in 39%; 10 tumours recurred (3.5%) after a median of 2.8 years. The recurrence rates differed significantly between both groups. Mean follow-up was 4.5 years.

CONCLUSIONS

3D-histology is a useful technique to detect tumour outgrowths at the excision margins, but required a high rate of re-excisions. 3D-histology was associated with a significantly lower LR rate than serial section histology.

[Surgical techniques in the treatment of basal cell carcinoma-a prospective investigation]

Hintergrund

Basalzellkarzinome sind die häufigsten epithelialen Hauttumoren und eine häufige Indikation für dermatologische Eingriffe. Trotz der Etablierung medikamentöser Therapieoptionen stellt die Operation weiterhin die Therapie der Wahl dar. Hierbei stehen verschiedene Möglichkeiten zur Verfügung, die von der Kürettage bis hin zu komplexen dermatochirurgischen Eingriffen reichen. Neben dem Hauptaspekt der geringen lokalen Rezidivraten sind auch ästhetische Faktoren und die Anzahl der Eingriffe für die Wahl der Therapie wichtig.

Methoden

In dieser Studie wurden 347 Patienten mit 398 Basalzellkarzinomen (nodulärer Typ, Durchmesser bis 10 mm) prospektiv untersucht. Die Patienten wurden randomisiert in 2 Behandlungsarme eingeteilt: In einer Gruppe wurden die Tumoren kürettiert, in der anderen Gruppe exzidiert. Als Kontrolle dienten Patienten, die im gleichen Untersuchungszeitraum 3‑D-histologisch kontrolliert operiert wurden.

Ergebnisse

Die höchste lokale Rezidivrate wurde nach der Kürettage (14,0 %) beobachtet, während die Gruppe mit 3‑D-Histologie die niedrigste Rezidivrate (0,9 %; p < 0,001) aufwies. In der 3‑D-Gruppe waren mehr Re-Exzisionen erforderlich, um eine vollständige Entfernung des Tumors zu erreichen, als in der Gruppe mit histologischen Serienschnitten. Die Patienten bewerteten das ästhetische Ergebnis am besten nach der Kürettage. Die mittlere Nachbeobachtungszeit betrug 3,9 Jahre.

Schlussfolgerung

Die Wahl der chirurgischen Therapie bei kleinen nodulären Basalzellkarzinomen hängt von den individuellen Gegebenheiten ab. 3‑D-histologisch kontrollierte Exzisionen mit Wundverschluss nach vollständiger Tumorentfernung zeigten in unserer Studie die geringste Rezidivrate. Aber auch die Kürettage stellt eine mögliche chirurgische Therapieoption mit minimalem Aufwand und einer akzeptablen Rezidivrate dar, die zu guten ästhetischen Ergebnissen führen kann.

S2k Guidelines for Cutaneous Basal Cell Carcinoma - Part 1: Epidemiology, Genetics and Diagnosis

Basal cell carcinoma is the most common malignant tumor among fair-skinned individuals, and its incidence has been rising steadily in the past decades. In order to maintain the highest quality of patient care possible, the German S2k guidelines were updated following a systematic literature search and with the participation of all professional societies and associations involved in the management of the disease. Part 1 highlights new developments in genetics in particular as well as aspects regarding epidemiology, diagnosis, and histology.

Diagnostic accuracy of a new ex vivo confocal laser scanning microscope compared to H&E-stained paraffin slides for micrographic surgery of basal cell carcinoma

BACKGROUND

For safe excision of malignant skin tumours, complete negative surgical margins are mandatory. The gold standard for analysis is frozen sections or paraffin-embedded haematoxylin and eosin (H&E)-stained slides. The production of H&E-stained slides is time-consuming (>20 h) while wounds remain unclosed. An upcoming method is confocal laser scanning microscopy (CLSM), a technique that scans unfixed fresh tissue rapidly.

OBJECTIVE

Evaluation of the process to generate and analyse CLSM images and assessment of the accuracy to detect basal cell carcinoma (BCC) tissue.

METHODS

Digital microscopic images were generated by the Histolog Scanner v1 from 544 fresh specimens of 148 BCCs that had been stained with a 0.01% proflavine solution. CLSM images were compared to the histological diagnoses of the corresponding H&E-stained slides.

RESULTS

A total of 525 images could be analysed. The sensitivity was 73% (95% CI = [65.27%; 80.47%]), and the specificity was 96% (95% CI = [93.40%; 97.60%]). Detection of BCCs in punch biopsies was certainly detected (sensitivity of 100%). The median total time to generate and evaluate a CLSM image was 5.17 min (maximum 20.17 min and minimum 2.05 min). The greatest challenge was flattening the specimen to assure complete representation of the surgical margins.

CONCLUSION

Confocal laser scanning microscopy is a time-saving and very effective alternative to classical paraffin-embedded or frozen sections. Patient treatment could be improved due to shorter hospital stays or faster outpatient therapy due to reduced intervals between surgical stages. Diagnostic accuracy of the microscope used still must be improved.

Pathways to clinical CLARITY: volumetric analysis of irregular, soft, and heterogeneous tissues in development and disease

Three-dimensional tissue-structural relationships are not well captured by typical thin-section histology, posing challenges for the study of tissue physiology and pathology. Moreover, while recent progress has been made with intact methods for clearing, labeling, and imaging whole organs such as the mature brain, these approaches are generally unsuitable for soft, irregular, and heterogeneous tissues that account for the vast majority of clinical samples and biopsies. Here we develop a biphasic hydrogel methodology, which along with automated analysis, provides for high-throughput quantitative volumetric interrogation of spatially-irregular and friable tissue structures. We validate and apply this approach in the examination of a variety of developing and diseased tissues, with specific focus on the dynamics of normal and pathological pancreatic innervation and development, including in clinical samples. Quantitative advantages of the intact-tissue approach were demonstrated compared to conventional thin-section histology, pointing to broad applications in both research and clinical settings.

S1 guideline: microscopically controlled surgery (MCS)

When using procedures that enable complete examination of surgical margins (3D histology), microscopically controlled surgery (MCS) represents a safe and proven method to confirm R0 resection of infiltrating tumors, especially at problematic sites, while preserving the adjacent tissue. This allows for excellent or good aesthetic results that are superior (cryosurgery, short-range irradiation) or equivalent (PDT) to nonsurgical and less safe procedures (PDT).

Basal cell carcinomata: Risk factors for incomplete excision and results of re-excision

INTRODUCTION

Re-excision of incompletely excised basal cell carcinomas (BCCs) can be unsatisfactory in the absence of residual tumours. Recommended guidelines do suggest re-excision as a treatment modality; however, its value has been questioned due to low or variable residual tumour presence. We analysed the incomplete excision and re-excision rates and the presence of residual tumours over an 18-month period in a single unit.

METHOD

Using pathology results and case notes, 2586 primary excisions of BCCs in 1717 patients were reviewed.

RESULTS

The incomplete excision rate was reported to be 7.1% (184/2586). Excision of a lesion by multiple excision lesion procedure was associated with a higher rate of incomplete excision when compared to single lesion excision procedure (61.5% vs. 38.5%). Of the incompletely excised BCCs, 33.6% (62/184) were re-excised, of which 62.9% (39/62) had residual tumours. Although the figures are small, most anatomical sites examined had a residual tumour presence >50%.

CONCLUSION

After evaluating each patient individually, considering the high residual tumour rate, re-excision of an incompletely excised BCC would be a worthwhile procedure.