Cutaneous keratinocyte cancers of the head and neck: Epidemiology, risk factors and clinical, dermoscopic and reflectance confocal microscopic features

Metastatic cutaneous squamous cell carcinoma accounts for nearly all squamous cell carcinomas of the parotid gland

Primary squamous cell carcinoma of the parotid gland (pSCCP) has long been recognized as a separate entity and is included in the WHO classifications of salivary gland tumors. However, it is widely accepted among head and neck pathologists that pSCCP is exceptionally rare. Yet, there are many publications describing series of pSCCP and data from SEER and other cancer register databases indicate erroneously an increasing incidence of pSCCP. Importantly, pSCCP and metastatic (secondary) squamous cell carcinoma to the parotid gland (mSCCP) have nearly identical histological features, and the diagnosis of pSCCP should only be made after the exclusion of mSCCP. Moreover, all of the histological diagnostic criteria proposed to be in favor of pSCCP (such as, for example, dysplasia of ductal epithelium) can be encountered in unequivocal mSCCP, thereby representing secondary growth along preexistent ducts. Squamous cell differentiation has also been reported in rare genetically defined primary parotid carcinomas, either as unequivocal histological squamous features (e.g., NUT carcinoma, mucoepidermoid carcinoma), by immunohistochemistry (e.g., in NUT carcinoma, adamantinoma-like Ewing sarcoma, basal-type salivary duct carcinoma, mucoepidermoid carcinoma), or a combination of both. Another major issue in this context is that the International Classification of Diseases (ICD) coding system does not distinguish between primary or metastatic disease, resulting in a large number of patients with mSCCP being misclassified as pSCCP. Immunohistochemistry and new molecular biomarkers have significantly improved the accuracy of the diagnosis of many salivary gland neoplasms, but until recently there were no biomarkers that can accurately distinguish between mSCCP and pSCCP. However, recent genomic profiling studies have unequivocally demonstrated that almost all SCCP analyzed to date have an ultraviolet light (UV)-induced mutational signature typical of mSCCP of skin origin. Thus, mutational signature analysis can be a very useful tool in determining the cutaneous origin of these tumors. Additional molecular studies may shed new light on this old diagnostic and clinical problem. This review presents a critical view of head and neck experts on this topic.

Grading differentiation in cutaneous squamous cell carcinoma: a review of the literature

Poor differentiation is strongly associated with poor outcomes in cutaneous squamous cell carcinoma (CSCC). In addition, the National Comprehensive Cancer Network (NCCN) guidelines designate poorly differentiated tumors as "very high risk". Despite its clear prognostic implications, there is no standardized grading system for CSCC differentiation in common use today. CSCC differentiation is graded inconsistently by both dermatopathologists and Mohs surgeons, and reliability studies have demonstrated suboptimal inter- and intra-rater reliability in both of these groups. The absence of a standardized and reliable grading system has impeded the use of differentiation in CSCC staging, despite its apparent correlation with disease outcomes. We performed a comprehensive review of the literature summarizing historical CSCC differentiation grading systems, as well as grading systems in non-cutaneous head and neck SCC as a point of reference. Relevant articles were identified by searching Embase and PubMed, as well as by reviewing reference lists for additional articles and histology textbook excerpts. CSCC grading systems that were identified and summarized include the historical Broders system, the World Health Organization system, the College of American Pathologists' system, and a system described by a 2023 Delphi consensus panel of dermatopathologists.

Diagnosis of invasive cutaneous squamous cell carcinoma, imaging and staging

The assessment of patients with a lesion raising the suspicion of an invasive cutaneous squamous cell carcinoma (cSCC) is a frequent clinical scenario. The management of patients with cSCC is a multistep approach, starting with the correct diagnosis. The two main diagnostic goals are to differentiate from other possible diagnoses and correctly recognize the lesion as cSCC, and then to determine the tumor spread (perform staging), that is if the patient has a common primary cSCC or a locally advanced cSCC, or a metastatic cSCC (with in-transit, regional lymph nodal, or rarely distant metastasis). The multistep diagnostic approach begins with the clinical characteristics of the primary cSCC, it is complemented with features with dermoscopy and, if available, reflectance confocal microscopy and is confirmed with histopathology. The tumor spread is assessed by physical examination and, in some cases, ultrasound and/or computed tomography or magnetic resonance imaging, mainly to investigate for regional lymph node metastasis or for local infiltration into deeper structures. In the last step, the clinical, histologic and radiologic findings are incorporated into staging systems.

Diagnostic Value of Dermoscopic Structures in Predicting Superficial Basal Cell Carcinoma in the Skin of Color

Background

Basal cell carcinoma (BCC) manifests different dermoscopic patterns in individuals with dark skin complexion compared to those with fair skin types. This study aimed to investigate the diagnostic utility of dermoscopy in discerning superficial BCC from other types of BCC, specifically in patients with dark skin complexion.

Materials and Methods

This cross-sectional study focuses on patients diagnosed with BCC who were referred for skin biopsy between July 2020 and September 2022. Initially, the demographic characteristics of patients, clinical attributes of lesions, and pathological sub-types of BCC were documented. Subsequently, videodermoscopy was employed to capture comprehensive views and dermoscopic images of the lesions. Univariate logistic regression analysis was then utilized to assess the reliability of dermoscopic structures in distinguishing superficial BCC from other BCC types. Last, the study evaluated the sensitivity, specificity, positive predictive value, and negative predictive value of dermoscopy in the differentiation of superficial BCC from other BCC sub-types.

Results

The study enrolled 49 patients diagnosed with BCC, with a mean age of 66.22 ± 10.41 years. The most prevalent pathological sub-type observed was nodular (53.1%). Dermoscopy exhibited a higher specificity compared to the naked eye in the differentiation of superficial BCC from other types (55% vs. 35%, respectively). Univariate analysis revealed a significant association between spoke-wheel structures and superficial BCC (P = 0.02, odds ratio = 7.2, 95% confidence interval = 1.35-38.32).

Conclusion

Dermoscopy exhibited superior specificity compared to the naked eye in differentiating superficial BCC from other BCC types. Notably, the spoke-wheel structure demonstrated the most robust correlation with superficial BCC.

Exogenous hormone therapy and non-melanoma skin cancer (keratinocyte carcinoma) risk in women: a systematic review and meta-analysis

Previous studies reported inconsistent results regarding the association between keratinocyte carcinoma (KC) and exogenous hormone therapy. This study aimed to investigate the association between the use of exogenous sex hormones and the risk of KC among women. The databases of PubMed, Ovid Medline, Cochrane, and Web of Science were searched until May 2023. A total of 5293 patients with KC and 106,424 controls were included for analysis. The meta-analysis indicated that oral contraceptives (OC) and hormonal replacement therapy (HRT) use were associated with an increased risk of squamous cell carcinoma (SCC) (OR/RR = 1.25, 95% CI 1.10 to 1.43, I2 = 41.6%, p = 0.080). Subgroup analysis showed that OC use increased the risk of SCC (OR/RR = 1.37, 95% CI 1.15 to 1.63), whereas no significant association was shown between HRT use and risk of SCC (OR/RR = 1.13, 95% CI 0.93 to 1.37). Additionally, OC and HRT use were linked to an increased risk of basal cell carcinoma (BCC) (OR/RR = 1.16, 95% CI 1.09 to 1.25, I2 = 30.1%, p = 0.188). Further subgroup analysis suggested both OC and HRT use were associated with an increased risk of BCC (OC: OR/RR = 1.13, 95% CI 1.01 to 1.25; HRT: OR/RR = 1.19, 95% CI 1.09 to 1.30). In conclusion, our findings support the hypothesis that the risk of KC among women may be affected by the use of exogenous hormones.

High-Dimensional and Spatial Analysis Reveals Immune Landscape-Dependent Progression in Cutaneous Squamous Cell Carcinoma

PURPOSE

The tumor immune microenvironment impacts the biological behavior of the tumor, but its effect on clinical outcomes in head and neck cutaneous squamous cell carcinomas (HNcSCC) is largely unknown.

EXPERIMENTAL DESIGN

We compared the immune milieu of high-risk HNcSCC that never progressed to metastasis with those that metastasized using multiparameter imaging mass cytometry. The cohort included both immunosuppressed patients (IS) and patients with an absence of clinical immune-suppression (ACIS). Spatial analyses were used to identify cellular interactions that were associated with tumor behavior.

RESULTS

Nonprogressing primary HNcSCC were characterized by higher CD8+ and CD4+ T-cell responses, including numerically increased regulatory T cells. In contrast, primary lesions from HNcSCC patients who progressed were largely devoid of T cells with lower numbers of innate immune cells and increased expression of checkpoint receptors and in the metastatic lesions were characterized by an accumulation of B cells. Spatial analysis reveals multiple cellular interactions associated with nonprogressing primary tumors that were distinct in primary tumors of disease-progressing patients. Cellular regional analysis of the tumor microenvironment also shows squamous cell-enriched tumor regions associated with primary nonprogressing tumors.

CONCLUSIONS

Effective responses from both CD8+ and CD4+ T cells in the tumor microenvironment are essential for immune control of primary HNcSCC. Our findings indicate that the early events that shape the immune responses in primary tumors dictate progression and disease outcomes in HNcSCC.

High Dose Rate Brachytherapy in non - melanoma skin cancer - systematic review

Non-melanoma skin cancers (NMSC's) are the most common malignancies worldwide. Millions of new cases every year present challenge to healthcare systems. Recent years brought numerous new data concerning High Dose Rate (HDR) brachytherapy as treatment option for NMSC's. International guidelines do not recognize brachytherapy as a method of choice given lack of randomized trials, however many prospective and retrospective studies show promising results. Aim of the study was to present the efficacy of HDR brachytherapy, with analysis of its safety and adverse effects based on review of the English published medical full-text papers. Literature review of thirteen articles published between 1999 and 2021 was performed. Pubmed and Google Scholar databases were searched on October 2021 using keywords: ((Basal cell carcinoma) OR (squamous cell carcinoma) OR (non-melanoma skin cancer)) AND (HDR brachytherapy). Fourteen full text English articles with follow up over 1 year and study group over 50 patients were included into analysis. In analyzed material 2403 patients received High Dose Rate brachytherapy. Local control varied between 71 and 99%.Dominant reported cosmetic effect was good or very good. Results were cross-referenced with recent meta-analyses comparing brachytherapy to surgical excision, Mohs microsurgery and external beam radiotherapy. Radiodermitis is the main adverse effect of radiation treatment during and after radiotherapy. HDR brachytherapy emerges as potentially non-inferior treatment method providing very good reported cosmetic outcomes.

When is a surgical multidisciplinary approach required in the management of head and neck non-melanoma skin cancer and in advanced head and neck pathologies involving skin?

Non-melanoma Skin cancer, including cutaneous squamous cell carcinoma and basal cell carcinoma, is the most common form of malignancy in the Caucasian population, and the skin of the head and neck is the site most involved. They should not be underestimated; in particular, high-risk lesions and advanced skin cancers require accurate diagnostic work up, aggressive surgical treatment and should be managed by the head and neck surgeon, the dermatologist and the plastic surgeon. Cutaneous head-neck malignancies are often overlooked or not routinely treated with a multidisciplinary surgical approach. Similarly, for primary head and neck cancers with involvement of surrounding skin, the involvement of the dermatologist and the plastic surgeon could better define an adequate diagnosis and treatment planning. The management of these patients presents both therapeutic and ethical problems, because the poor prognosis is burdened by facial disfigurement, open malodorous wounds and intractable pain. Therefore, in patients with advanced disease that is not candidate to radical surgery, palliative surgery with flap reconstruction could take place and could be proposed to improve quality of life.

The Role of TROP2 in BCC and Cutaneous SCC: A Clinical and Immunohistochemical Study

BACKGROUND

Nonmelanoma skin cancer (NMSC) mainly includes basal (BCC) and squamous (SCC) cell carcinoma. Trophoblast cell-surface antigen2 (TROP2), a cell-signal transduction, is one of the tumor-related calcium signal transducer gene family. TROP2 was highly expressed in many cancers, however, its role in BCC and SCC has not yet been studied.

OBJECTIVE

To investigate TROP2 immunohistochemical expression in BCC and SCC (lesional and peri-lesional) skin compared to controls and correlates its expression with the clinicopathologic parameters of the studied cases.

METHODS

This case-control study included 17 BCC and 15 SCC patients as well as 12 age and sex matched controls. History and clinical examination were completed. Histological examination of skin biopsies was done together with TROP2 immune-staining.

RESULTS

In the studied BCC and SCC cases, there was a significant stepwise up-regulation of TROP2 H score from control to peri-lesional, ended by lesional epidermis in one hand (p=0.003 for BCC and p<0.001 for SCC) and tumor island in another hand (p=0.001 for BCC and p=0.003 for SCC). TROP2 expression in both BCC and SCC tumor tissues was not affected by any of the studied clinicopathological parameters of the investigated cases.

CONCLUSION

TROP2 could have an important role in BCC and SCC pathogenesis. TROP2 targeting may have appraising effect in clinical application in BCC and SCC management.

High-frequency ultrasound in the diagnosis of the spectrum of cutaneous squamous cell carcinoma: Noninvasively distinguishing actinic keratosis, Bowen's Disease, and invasive squamous cell carcinoma

OBJECTIVE

To evaluate high-frequency ultrasound (HFUS) features for diagnosing cutaneous squamous cell carcinoma (cSCC) as a spectrum of progressively advanced malignancies, including precursor actinic keratosis (AK), Bowen's disease (BD), and invasive squamous cell carcinoma (iSCC).

METHOD

In this retrospective study, 160 skin lesions diagnosed histopathologically (54 AK, 54 BD, and 52 iSCC) in 160 patients were included. The HFUS features of AK, BD, and iSCC were analyzed. The obtained data were evaluated using univariate and forward multivariate logistic regression analyses.

RESULTS

The most significant HFUS features in AK were regular surface (odds ratio [OR], 8.42) and irregular basal border (OR, 6.36). The most significant HFUS features in BD were crumpled surface (OR, 19.62) and layer involvement confined to the epidermis (OR, 3.96). The most significant HFUS features in iSCC were concave surface (OR, 27.06), stratum corneum (SC) detachment (OR, 14.41), irregular basal border (OR, 4.01), and convex surface (OR, 3.73). The characteristics of surface features, basal border, and layer involvement could be valuable HFUS clues in the discrimination of AK, BD, and iSCC.

CONCLUSION

High-frequency ultrasound is valuable for the differentiation of AK, BD, and iSCC, which may allow dynamic and noninvasive monitoring in the spectrum of cSCC.

Misinterpretation of head and neck masses can delay the correct diagnosis. A two-step demolitive-reconstruction surgery for saving patient's life

OBJECTIVE

To present a rare case of sebaceous cyst masking skin squamous carcinoma. The delayed diagnosis made necessary a two-step (demolition and reconstruction) surgery to save patient's life.

MATERIAL AND METHODS

A 77-year-old male, suffering from persistent right hemicrania and eye pain referred to different specialists, who misinterpreted his symptoms. The man presented on the right zygomatic area a big sebaceous cyst which masked a squamous cells carcinoma (SCC) infiltrating the surrounding structures including the orbito zygomatic complex and the orbital content that was the cause of the symptoms. Patient underwent biopsy, CT thorax and MRI of the head and neck as pre-operative examinations. A two-step surgery was performed to remove the tumor.

RESULTS

The skin biopsy showed the presence of sun damaged skin contains moderately differentiated invasive SCC within the context of sebaceous cyst. While the CT chest was negative, the head and neck MRI showed a huge tumor invading the orbit and periorbital tissue, the zygomatic bone and the soft tissues up to the posterior orbital area, without presence of neck lymph nodes. Le lesion has been classified as cT4 N0 M0 (TNM 8) and a two-step surgery approach (demolition and reconstruction) was performed with successful results at 1 year-follow up.

CONCLUSIONS

The delayed diagnosis of SCC was due to the misdiagnosis of the signs of the tumor invasion. Demolitive and reconstructive surgeries allowed to preserve patient's life. The careful attention to patient's skin characteristic, the analysis of general and local clinical signs (irradiated pain, cyst and skin type) and the evaluation of the complex differential diagnosis could be the key to avoid delayed treatment in head and neck cancer.

The first report of diagnosing of keratoacanthoma in Chinese Han patients using dermoscopy and reflectance confocal microscopy

BACKGROUND

Keratoacanthoma (KA) is a special kind of tumor, which is regarded as a variant of squamous cell carcinoma (SCC) in some academic disciplines. But differentiating KA from SCC remains a diagnostic challenge. The noninvasive techniques dermoscopy and reflectance confocal microscopy (RCM) can provide new insights for diagnosis.

OBJECTIVE

To observe the characteristics of KA under dermoscopy and reflectance confocal microscopy (RCM), in order to gain experience and reference for clinicians to facilitate earlier diagnosis.

METHODS

We collected two cases of KA, which were confirmed by clinical and histopathological examination. The two cases were examined by dermoscopy and RCM, respectively. Then, we collected the microscopic characteristics of KA lesions.

RESULTS

The dermoscopy features of KA are concentric circles of central crater, keratin mass, keratin scale, and polymorphic vascular pattern. The RCM features are described as refractile crust, atypical honeycomb pattern, dark center cells, large round nucleated cells, dendritic cells, and linear or round vessels traversing dermal papillae in the dermis.

CONCLUSION

KA has some specific dermoscopy and RCM features, which can provide a basis for doctors to diagnose and intervene earlier.