Ex Vivo High-Frequency Ultrasound for Assessment of Basal Cell Carcinoma

Diagnostic accuracy of high-frequency ultrasound for cutaneous neoplasms: a narrative review of the literature

High-frequency ultrasound has been used to visualize depth and vascularization of cutaneous neoplasms, but little has been synthesized as a review for a robust level of evidence about the diagnostic accuracy of high-frequency ultrasound in dermatology. A narrative review of the PubMed database was performed to establish the correlation between ultrasound findings and histopathologic/dermoscopic findings for cutaneous neoplasms. Articles were divided into the following four categories: melanocytic, keratinocytic/epidermal, appendageal, and soft tissue/neural neoplasms. Review of the literature revealed that ultrasound findings and histopathology findings were strongly correlated regarding the depth of a cutaneous neoplasm. Morphological characteristics were correlated primarily in soft tissue/neural neoplasms. Overall, there is a paucity of literature on the correlation between high-frequency ultrasound and histopathology of cutaneous neoplasms. Further studies are needed to investigate this correlation in various dermatologic conditions.

Rationale for Using High-Frequency Ultrasound as a Routine Examination in Skin Cancer Surgery: A Practical Approach

Ultrasound and high-frequency ultrasound assessment of melanoma and non-melanoma skin cancer in the pre-therapeutical setting is becoming increasingly popular in the field of dermatosurgery and dermatooncology, as it can provide clinicians with relevant, "in vivo" parameters regarding tumor lateral and depth extension as well as potential locoregional spread, cancelling the need of more extensive imaging methods and avoiding a delay in diagnosis. Furthermore, preoperative sonography and color Doppler can aid in orienting the clinical diagnosis, being able in numerous situations to differentiate between benign and malignant lesions, which require a different therapeutic approach. This preoperative knowledge is of paramount importance for planning an individualized treatment regimen. Using sonography at the time of diagnosis, important surgical complications, such as neurovascular damage, can be avoided by performing a preoperative neurovascular mapping. Furthermore, sonography can help reduce the number of surgical steps by identifying the lesions' extent prior to surgery, but it can also spare unnecessary surgical interventions in cases of locally advanced lesions, which infiltrate the bone or already present with locoregional metastases, which usually require modern radiooncological therapies in accordance to European guidelines. With this review, we intend to summarize the current indications of sonography in the field of skin cancer surgery, which can help us improve the therapeutic attitude toward our patients and enhance patient counseling. In the era of modern systemic radiooncological therapies, sonography can help better select patients who qualify for surgical procedures or require systemic treatments due to tumoral extension.

Ultrasound Assessment of Skin Tumors Local Recurrence

Skin cancer may recur at or around the surgical site despite wide excisions. Prompt clinical and sonographic detection of local recurrence is important since subjects with relapsing melanomas or nonmelanoma malignancies can be managed efficaciously, with a relevant impact on morbidity and survival. Ultrasound is being employed with increasing frequency in the assessment of skin tumors, but most of the published articles relate to initial pretherapeutic diagnosis and staging. This review aims to offer an illustrated guide to the sonographic evaluation of locally recurring skin cancer. We introduce the topic, then we provide some sonographic tips for patient follow-up, then we describe the ultrasound findings in case of local recurrence, illustrating the main mimickers, and finally, we mention the role of ultrasound in guiding diagnostic and therapeutic percutaneous procedures.

High-Frequency Ultrasound in Diagnosis and Treatment of Non-Melanoma Skin Cancer in the Head and Neck Region

Non-melanoma skin cancer is one of the most frequently diagnosed cancers in the human body and unfortunately the incidence continues to increase. NMSC is represented by the basal cell carcinomas (BCCs) and squamous cell carcinomas (SCCs), which are the most prevalent forms, and basosquamous cell carcinomas (BSC) together with Merkel cell carcinoma (MCC), which are rare types but with a very aggressive pattern and poor prognosis. The pathological diagnosis is hard to assess without a biopsy, even by the dermoscopy. Moreover, the staging can be problematic because there is no access clinically to the thickness of the tumor and the depth of the invasion. The aim of this study was to evaluate the role of ultrasonography (US), which is a very efficient imaging method, non-irradiating and cheap, in diagnosis and treatment of non-melanoma skin cancer in the head and neck region. Thirty-one patients with highly suspicious malignant lesions of the head and neck skin were evaluated in the Oral and Maxillo-facial Surgery Department and Imaging Department in Cluj Napoca, Romania. All tumors were measured with three transducers: 13 MHz, 20 MHz and 40 MHz. Doppler examination and elastography were also used. The length, width, diameter, thickness, the presence of necrosis, status of regional lymph nodes, the presence of hyperechoic spots, strain ratio and vascularization were all recorded. After that, all patients were treated by surgical resection of the tumor and reconstruction of the defect. Immediately after surgical resection, all tumors were measured again after the same protocol. The resection margins were evaluated by all three types of transducers in order to detect malignant involvement and the results were compared with the histopathological report. We found that the 13 MHz transducers offered a big picture of the tumor but the level of details, in the form of the presence of the hyperechoic spots, is reduced. We recommend this transducer for evaluation of surgical margins or for the large skin tumors. The 20 and 40 MHz transducers are better for viewing the particularities of malignant lesions and for an accurate measurement; however, in the case of large size lesions, assessing all three dimensions of the tumor can be difficult. The intralesional hyperechoic spots are present in case of BCC and they can be used for differential diagnosis of BCC.

Imaging technologies for presurgical margin assessment of basal cell carcinoma

Basal cell carcinoma is the most common cancer worldwide, necessitating the development of techniques to decrease treatment costs through efficiency and efficacy. Mohs micrographic surgery, a specialized surgical technique involving staged resection of the tumor with complete histologic evaluation of the peripheral margins, is highly utilized. Reducing stages by even 5% to 10% would result in significant improvement in care and economic benefits. Noninvasive imaging could aid in both establishing the diagnosis of suspicious skin lesions and streamlining the surgical management of skin cancers by improving presurgical estimates of tumor sizes. Herein, we review the current state of imaging techniques in dermatology and their applications for diagnosis and tumor margin assessment of basal cell carcinoma prior to Mohs micrographic surgery.

Virtual segmentation of three-dimensional ultrasound images of morphological structures of an ex vivo ectopic pregnancy inside a fallopian tube

Ex vivo ultrasound (US) of human tissues has been used for decades on the study of the acoustic physical aspects of the US, to the study of the morphology of the organs. Using three-dimensional (3D) US, we demonstrate the possibilities to study surgical specimens from gynecological conditions. 3D images of the surgical specimen were collected and virtually segmented according to the contrast of its images, providing a 3D image of the ectopic pregnancy and its effects on the fallopian tube.

Performance of Ultrasound for Identifying Morphological Characteristics and Thickness of Cutaneous Basal Cell Carcinoma: A Systematic Review

Advances in ultrasound technology and non-surgical treatments of basal cell carcinomas (BCCs) have raised the need to study the performance of high-frequency ultrasound (HFUS) in BCCs. We aimed to assess the performance of HFUS in the evaluation of BCCs to formulate recommendations for its uses and conducted a systematic review of the literature to do so. A search of Central, Medline, Embase, CINHAL, and Web of Science was performed using key/MESH terms "ultrasonography" and "basal cell carcinoma" (January 2005-December 2020). We included primary studies reporting biopsy-confirmed BCCs for which the target intervention was ultrasound assessment at 15 MHz or higher frequency. Thirty articles were included, studying a total of 1,203 biopsy-confirmed BCCs. HFUS provides accurate depth measurements, especially for BCCs >1 mm. The definition of lateral margins in vivo needs further studies; however, ex vivo margin assessment seems convincing. There is a diagnostic role for HFUS in identifying higher recurrence risk BCC subtypes, which can help in risk stratification. Performance of HFUS is significant in BCC management. Pre-surgical scans may support case selection for Mohs. HFUS can improve safety when used to plan brachytherapy treatments, help with case selection and adjunct treatment choice pre-photodynamic therapy. Finally, HFUS can help follow lesions after intervention, particularly non-surgical management, and support the decision to observe or re-intervene. HFUS can enhance clinical practice by providing useful information that cannot be deducted from the clinical examination. It would be recommended to evaluate the extent, mainly depth, and detect the aggressiveness of the BCCs.

Muffin Technique Micrographic Surgery for Non-melanoma Skin Cancer

Background: Mohs micrographic surgery (MMS) is the gold standard treatment for high-risk facial non-melanoma skin cancer. However, patients' access to MMS is limited by cost. The muffin technique micrographic surgery (MTMS) is an alternative micrographic technique wherein the entire excised margin is evaluated post-operatively by a pathologist using paraffin-embedded material. Herein, we describe the implementation and the preliminary results of MTMS in an academic dermatology center.

Objective: To describe the MTMS and outline its efficacy and safety in a real-world clinical academic setting.

Methods: A retrospective chart review was conducted of all patients with basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) who underwent MTMS at the University of Alberta Dermatology Center from June 2016 until July 2019.

Results: A total of 69 patients were included (64 BCCs and 5 SCCs). 68.1% of surgeries had clear margins following the first incision, 100% after second round re-excisions. There were no observed cases of tumor recurrence after a median 40 months of follow-up. There were no major adverse events or complications.

Conclusions: MTMS is a superior alternative to simple excision of skin cancer by providing full margin control and residual tumor mapping.