Basal cell carcinoma: a comprehensive review for the radiologist

18F-FDG PET/CT findings in nevoid basal cell carcinoma syndrome: a systematic review and a new case report

BACKGROUND

To demonstrate and analyze the 18F-FDG positron emission tomography/computed tomography (PET/CT) findings in this rare nevoid basal cell carcinoma syndrome (NBCCS).

CASE PRESENTATION

A 71-year-old woman with the left invasive breast cancer was treated with hormone therapy for six months and underwent the 18F-FDG PET/CT examination for efficacy evaluation. 18F-FDG PET/CT revealed the improvement after treatment and other unexpected findings, including multiple nodules on the skin with 18F-FDG uptake, bone expansion of cystic lesions in the bilateral ribs, ectopic calcifications and dilated right ureter. She had no known family history. Then, the patient underwent surgical excision of the all skin nodules and the postoperative pathology were multiple basal cell carcinomas. Finally, the comprehensive diagnosis of NBCCS was made. The patient was still in follow-up. Additionally, we have summarized the reported cases (n = 3) with 18F-FDG PET/CT from the literature.

CONCLUSIONS

It is important to recognize this syndrome on 18F-FDG PET/CT because of different diagnoses and therapeutic consequences.

Skin Malignancies: Imaging Review with Radiologic-Histopathologic Correlation

Skin malignancies are commonly encountered as primary or incidental findings. Neoplasms that affect the skin include primary (basal cell carcinoma, squamous cell carcinoma, melanoma, and Merkel cell carcinoma) and secondary (mesenchymal neoplasms, lymphoma, and metastases) tumors. Imaging provides valuable anatomic information (tumor size, depth of involvement, presence of distant metastasis, and data for guiding biopsy) and functional information (metabolic activity and sentinel node mapping data). This information, in addition to biopsy results, improves the histopathologic characterization of tumors and treatment planning. Various histopathologic types of the same entity exhibit different biologic behavior and have different imaging features. Familiarity with the multimodality imaging features, histopathologic characteristics, and various modes of dissemination (direct invasion; perineural, lymphatic, and hematogenous spread) of the most common skin malignancies helps radiologists narrow the differential diagnosis in clinical practice. ©RSNA, 2023 Supplemental material is available for this article. Quiz questions for this article are available through the Online Learning Center.

Recurrence Following Globe Sparing Excision for Basal Cell Carcinoma with Anterior Orbital Invasion

PURPOSE

Globe-sparing excision for periocular basal cell carcinoma (BCC) with orbital invasion has evident benefits, but the ensuing morbidity and characteristics of recurrence are not well elucidated. This study aims to describe the extent of visual morbidity following globe-sparing excision, and the clinicoradiological characteristics of tumor recurrence.

METHODS

Multicentre retrospective case series.

RESULTS

Eight patients were identified for inclusion in this series. Time to recurrence following globe-sparing excision ranged from 3 to 12 years. Seven patients (87.5%) presented with recurrent disease originating from the medial canthus. Clinical features at presentation included contracture ( n =4, 50.0%), upper lid ptosis ( n =3, 37.5%), a palpable mass ( n =2, 25.0%), and hypoesthesia ( n =2, 25.0%). Radiologically, tumor recurrence was predominantly characterized by isointense signals on T1 and T2-weighted sequences ( n =5, 62.5%) with moderate contrast enhancement. The most common histologic subtype in recurrent tumors was a mixed nodular and infiltrative growth pattern ( n =5, 62.5%). Perineural invasion was a feature in four (50%) cases. Salvage therapy in the form of exenteration was performed in seven cases. Vismodegib and adjuvant radiotherapy were provided for one case with surgically unresectable tumor recurrence.

CONCLUSIONS

Globe-sparing excision for invasive periocular BCC can be complicated by late recurrence that develops rapidly despite silent neuroimaging for years. Early clinical signs are subtle. High-risk features predictive of recurrence include medial canthus location, mixed histological subtypes, and perineural invasion. Patients with such characteristics require lifelong clinical and imaging surveillance following globe-sparing excision.

Management of Non-Melanoma Skin Cancer: Radiologists Challenging and Risk Assessment

Basal cell carcinoma, squamous cell carcinoma, and Merkel cell carcinoma are the three main types of nonmelanoma skin cancers and their rates of occurrence and mortality have been steadily rising over the past few decades. For radiologists, it is still difficult to treat patients with advanced nonmelanoma skin cancer. Nonmelanoma skin cancer patients would benefit greatly from an improved diagnostic imaging-based risk stratification and staging method that takes into account patient characteristics. The risk is especially elevated among those who previously received systemic treatment or phototherapy. Systemic treatments, including biologic therapies and methotrexate (MTX), are effective in managing immune-mediated diseases; however, they may increase susceptibility to NMSC due to immunosuppression or other factors. Risk stratification and staging tools are crucial in treatment planning and prognostic evaluation. PET/CT appears more sensitive and superior to CT and MRI for nodal and distant metastasis as well as in surveillance after surgery. The patient treatment response improved with advent and utilization of immunotherapy and different immune-specific criteria are established to standardized evaluation criteria of clinical trials but none of them have been utilized routinely with immunotherapy. The advent of immunotherapy has also arisen new critical issues for radiologists, such as atypical response pattern, pseudo-progression, as well as immune-related adverse events that require early identification to optimize and improve patient prognosis and management. It is important for radiologists to have knowledge of the radiologic features site of the tumor, clinical stage, histological subtype, and any high-risk features to assess immunotherapy treatment response and immune-related adverse events.

The diagnostic value of imaging techniques for keratoacanthoma: A review

Keratoacanthoma (KA) is a fast-growing skin tumor with solitary KA being the most common type. KAs rarely metastasize and subside spontaneously. Although histopathology is the gold standard for the diagnosis of KA, its histopathological features are sometimes difficult to distinguish from those of other skin tumors. Imaging studies have certain advantages in the preoperative diagnosis of KA; they not only show the exact shape of the lesion but can also accurately determine the extent of the lesion. Combined with histopathological examination, these findings help establish a diagnosis. By summarizing the imaging features of KA, this article aimed to improve radiologists' understanding of the disease and help in the clinical and differential diagnosis of KA.

Basal Cell Carcinoma With Perineural Invasion: A Systematic Review and Pooled Survival Analysis

BACKGROUND

Perineural invasion (PNI) is considered a high-risk histopathologic feature in many skin cancers. Perineural invasion is a well-known poor prognostic factor of squamous cell carcinoma, but is poorly understood in the context of basal cell carcinoma (BCC).

OBJECTIVE

To analyze available demographic, clinical, and treatment data for BCC with PNI and the effect of these variables on recurrence patterns, disease progression, and cancer-specific mortality (CSM).

METHODS

A systematic review and pooled-survival analysis was performed using case reports and series of patients with perineural BCC.

RESULTS

This review included 159 patients from 49 publications. Of these cases, 57 patients reported at least one recurrence. Where reported, median follow-up time was 31 months for patients without recurrence ( n = 79) and 21 months for patients with recurrence ( n = 32). The cumulative incidence of CSM at 5 years was 8.5% (95% confidence interval [CI] 0.028-0.186) and the overall five-year survival was 90.9% (95% CI 0.796-0.961).

CONCLUSION

Male gender, multifocal nerve involvement, presence of clinical symptoms, and PNI detected on imaging are associated with poor prognosis of BCC with PNI. The high rate of disease recurrence and suboptimal cumulative incidence of CSM highlights the importance of early clinical detection, before the onset of symptomatic PNI and multifocal nerve involvement.

Modulation of Hedgehog Signaling for the Treatment of Basal Cell Carcinoma and the Development of Preclinical Models

Basal Cell Carcinoma (BCC) is the most commonly diagnosed cancer worldwide. While the survivability of BCC is high, many patients are excluded from clinically available treatments due to health risks or personal choice. Further, patients with advanced or metastatic disease have severely limited treatment options. The dysregulation of the Hedgehog (Hh) signaling cascade drives onset and progression of BCC. As such, the modulation of this pathway has driven advancements in BCC research. In this review, we focus firstly on inhibitors that target the Hh pathway as chemotherapeutics against BCC. Two therapies targeting Hh signaling have been made clinically available for BCC patients, but these treatments suffer from limited initial efficacy and a high rate of chemoresistant tumor recurrence. Herein, we describe more recent developments of chemical scaffolds that have been designed to hopefully improve upon the available therapeutics. We secondly discuss the history and recent efforts involving modulation of the Hh genome as a method of producing in vivo models of BCC for preclinical research. While there are many advancements left to be made towards improving patient outcomes with BCC, it is clear that targeting the Hh pathway will remain at the forefront of research efforts in designing more effective chemotherapeutics as well as relevant preclinical models.

Basal cell carcinoma: Histopathological gamut

Introduction

Basal cell carcinoma is the most common cutaneous malignancy which is exclusively observed on sun exposed and hair bearing areas of the face.

Diagnosis

We report two rare cases of basal cell carcinoma, which presented as a diagnostic challenge because of rare histopathology.

Findings

Both cases showed pigmentation, while one case resembled adenoid cystic carcinoma because of the glandular and ductal pattern of basaloid cells.

Result

We present these cases because of rare histopathologic presentation.

Pathogenesis of Keratinocyte Carcinomas and the Therapeutic Potential of Medicinal Plants and Phytochemicals

Keratinocyte carcinoma (KC) is a form of skin cancer that develops in keratinocytes, which are the predominant cells present in the epidermis layer of the skin. Keratinocyte carcinoma comprises two sub-types, namely basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). This review provides a holistic literature assessment of the origin, diagnosis methods, contributing factors, and current topical treatments of KC. Additionally, it explores the increase in KC cases that occurred globally over the past ten years. One of the principal concepts highlighted in this article is the adverse effects linked to conventional treatment methods of KC and how novel treatment strategies that combine phytochemistry and transdermal drug delivery systems offer an alternative approach for treatment. However, more in vitro and in vivo studies are required to fully assess the efficacy, mechanism of action, and safety profile of these phytochemical based transdermal chemotherapeutics.

Giant Basal Cell Carcinoma of the Scalp with Intracranial Invasion: MRI Findings with Tract Visualisation

A rare case of recurrent basal cell carcinoma in the scalp that infiltrated multiple intracranial structures is presented. Basal cell carcinoma represents one of the most frequent malignant nonmelanotic skin neoplasms, but the majority of them have no aggressive and recurrent behaviour. The aim of this case report is to provide an overview of the main clinical and radiologic features of basal cell carcinoma, focusing on the conventional and advanced (tractography) MRI findings and providing an overview of treatment and prognosis.

Magnetic Resonance Imaging Findings Differentiating Cutaneous Basal Cell Carcinoma from Squamous Cell Carcinoma in the Head and Neck Region

Objective

This study aimed to evaluate the efficacy of magnetic resonance (MR) imaging in differentiating between cutaneous basal cell carcinoma (cBCC) and cutaneous squamous cell carcinoma (cSCC) in the head and neck region.

Materials and Methods

Among patients with cutaneous head and neck cancers, 14 with primary cBCCs and 15 with primary cSCCs with a histologic tumor height of ≥ 4 mm underwent MR examinations; the findings were then examined for correlations.

Results

cBCCs (71%) occurred more frequently on the nose than cSCCs (13%) (p < 0.01). The maximum diameter (23.5 ± 7.2 mm vs. 12.7 ± 4.5 mm; p < 0.01) and diameter-to-height ratio (2.8 ± 0.9 vs. 1.7 ± 0.4; p < 0.01) were significantly greater in cSCCs than in cBCCs. Superficial ulcer formation (67% vs. 21%; p < 0.05), protrusion into the subcutaneous tissue (60% vs. 21%; p < 0.05), ill-demarcated deep tumor margins (60% vs. 7%; p < 0.01), and peritumoral fat stranding (93% vs. 7%; p < 0.01) were more frequently observed in cSCCs than in cBCCs. Intratumoral T2-hyperintense foci (57% vs. 13%; p < 0.05) were more frequently observed in cBCCs than in cSCCs.

Conclusion

cBCCs predominantly occurred on the nose with intratumoral T2-hyperintense foci, whereas cSCCs predominantly exhibited a flattened configuration, superficial ulcer formation, protrusion into the subcutaneous tissue, ill-demarcated deep tumor margin, and peritumoral fat stranding.

Prevalence of Perineural Invasion in keratinocyte cancer in the general population and among organ transplant recipients

BACKGROUND/OBJECTIVES

Basal cell carcinomas (BCCs) and cutaneous squamous cell carcinomas (SCCs) are the most commonly encountered cancers in fair-skinned populations worldwide. Perineural invasion is associated with worse outcomes for patients with BCC or SCC. Estimates of perineural invasion prevalence range widely, likely reflecting non-representative patient samples. We sought to determine the prevalence of perineural invasion in BCC and SCC in the general population, as well as among cancers arising in solid organ transplant recipients.

METHODS

We retrospectively analysed histopathology reports of BCC and SCC from patients enrolled in the QSkin Study (a population-based cohort of 43 794 Queensland residents recruited 2010-2011) and the Skin Tumours in Allograft Recipients (STAR) study (a cohort of 509 high-risk kidney or liver transplant recipients at the Princess Alexandra Hospital, Brisbane, recruited 2012-2014.) We estimated the prevalence of perineural invasion (and 95% confidence interval) in BCC and SCC, respectively, and identified clinical factors associated with perineural invasion.

RESULTS

In QSkin, we observed 35 instances of perineural invasion in 9850 histopathologically confirmed BCCs (0.36%) and 9 instances of perineural invasion in 3982 confirmed SCC (0.23%) lesions. In the STAR cohort, we identified 4 lesions with perineural invasion in 692 BCCs (0.58%) and 16 reports of perineural invasion in 875 SCC lesions (1.9%).

CONCLUSIONS

These data suggest that the overall prevalence of perineural invasion in keratinocyte cancer is low, although perineural invasion prevalence may be slightly higher among organ transplant recipients when compared to the general population.

Clear Cell Hidradenoma: Characteristic Imaging Features on Ultrasonography, Computed Tomography, and Magnetic Resonance Imaging

OBJECTIVES

The purpose of this study was to evaluate the imaging features of clear cell hidradenoma on ultrasonography (US), computed tomography (CT), and magnetic resonance imaging (MRI).

METHODS

The radiologic and pathologic databases at 2 medical institutions were searched retrospectively from 2004 to 2016 to identify patients with a diagnosis of clear cell hidradenoma. Ultrasonographic, CT, and MRI features were described, and pathologic specimens were reviewed.

RESULTS

There were 5 female and 4 male patients. The mean patient age was 48.9 years (range, 28-70 years). Five patients underwent only US; 2 patients underwent only CT; 1 patient underwent both US and CT; and 1 patient underwent US and MRI. Most of the tumors were located primarily in the subcutaneous fat layer. The mean tumor size was 18.4 mm. On US, 6 masses had a heterogeneous echo texture, including an anechoic portion with protruding echogenic portions. Two masses had multiple septa in the anechoic portion. On color Doppler US, blood flow was both central and peripheral in 5 patients. All 3 cases seen on CT presented as a low-attenuation mass with an enhanced solid internal nodule. On MRI, the mass showed heterogeneous signal intensity on T2-weighted images and enhancement of the peripheral wall and internal solid component on contrast-enhanced T1-weighted images.

CONCLUSIONS

Clear cell hidradenoma is usually located in the subcutaneous fat layer, has a well-defined margin, appears as a cystic mass with an internal solid nodule, and occasionally has multiple septa on US, CT, and MRI.