The detection of human papillomavirus-16 in squamous cell carcinoma of the nail unit: A case series

Mutational landscape in squamous cell carcinoma of the nail unit

Squamous cell carcinoma (SCC) is the most common malignancy of the nail unit. Pathogenetic mechanisms are yet to be determined, and a deeper molecular characterization of this disease is still necessary. The aim was to obtain a molecular characterization of NU SCC samples using an NGS approach to identify the genetic drivers involved in this tumor. The presence of HPV infection was also assessed. Furthermore, the mutational status was correlated with specific clinical-pathological features for a better insight into the carcinogenesis of this uncommon tumor. We analysed twenty paraffin-embedded nail unit SCC samples from patients diagnosed with primary SCC of the nail unit by next genome sequencing. In the 20 tested samples, the neoplastic cells enrichment ranged from 10% to 50% (mean value: 25.7%). In 14/20 cases (70.0%), at least one mutation was detected; whereas in the other six cases (30.0%), no alterations were observed ('wild-type/WT cases'). Overall, a total of 23 mutations were identified in the 20 specimens. TP53 was the most mutated gene (6/20 cases, 30.0%), while cKit, GNAS, EGFR, DICER1 and CTNNB1 were observed in one sample each (5.0%). No clinical-pathological parameters (age, sex, depth of invasion-DOI, histological subtype, grading and HPV) were significantly associated with the mutational status. The nail unit SCC mutational landscape appeared to be heterogeneous, favouring the hypothesis of a complex pathogenesis and an interaction of multiple elements, including HPV infections. This wealth of information undoubtedly improves our understanding of SCC biology.

Viruses and Skin Cancer

Advances in virology and skin cancer over recent decades have produced achievements that have been recognized not only in the field of dermatology, but also in other areas of medicine. They have modified the therapeutic and preventive solutions that can be offered to some patients and represent a significant step forward in our knowledge of the biology of skin cancer. In this paper, we review the viral agents responsible for different types of skin cancer, especially for solid skin tumors. We focus on human papillomavirus and squamous cell cancers, Merkel cell polyomavirus and Merkel cell carcinoma, and human herpesvirus 8 and Kaposi’s sarcoma.

Nail squamous cell carcinoma: A hidden high-risk human papillomavirus reservoir for sexually transmitted infections

Human papillomavirus (HPV) causes cervical cancer, anal cancer, vulvar cancer, vaginal cancer, penile cancer, and oropharyngeal cancer. Squamous cell carcinoma (SCC) in the genital region in particular is recognized to be caused by HPV infection, and intraepithelial lesions of the penis and vulva are termed penile intraepithelial neoplasia and vulvar intraepithelial neoplasia, respectively. Although SCC of the nail apparatus is recognized as being associated with high-risk HPVs, it is not well-known in general medicine, and its analysis has been insufficient. In this article, we reviewed 136 cases of HPV-associated nail SCC and SCC in situ and delineated their clinical characteristics. We found that half of the cases were high-risk HPV-associated. Almost all of the types were high-risk α-HPVs. This disease had a male dominance and left hand digit 3 and right hand digits 1-3 were typically affected. In this review, 24% of the cases of nail SCC had a history of other HPV-associated diseases, suggesting the possibility of genitodigital transmission. We propose that nail SCC is a hidden high-risk HPV-associated reservoir and should be recognized as a sexually transmitted infection.

Squamous cell carcinoma of the nail unit: a retrospective review of 19 cases in Asia and comparative review of Western literature

BACKGROUND

Reports regarding squamous cell carcinoma of the nail unit (SCCnu) are rare in Asia.

OBJECTIVES

To investigate the features of SCCnu in the Asian population.

METHOD

We performed a retrospective review of patients diagnosed with SCCnu at our institution between 2012 and 2017.

RESULTS

Nineteen cases were included. Thirteen patients were male (68.4%). The fingers were most frequently affected (73.7%). Mean delay to diagnosis was 62.4 months. Misdiagnosis rate was high (78.9%). Frequent clinical features were subungual tumor, subungual hyperkeratosis, nail dystrophy, ulcer, and nail loss. The majority of cases were invasive SCC in 15 cases (78.9%), while SCC in situ was found in four cases (21.1%). Local recurrence was detected in two cases (10.5%) following surgical resection. However, distant metastasis was not reported.

CONCLUSION

This study provides data of 19 SCCnu cases in Asia. Clinical characteristics of SCCnu in this study were similar to those of reports from Western countries. However, we found a higher frequency of more invasive cases and longer delay to diagnosis in our study; this advocates the need for greater attention on nail disorders among healthcare providers, particularly in Asia.

Squamous cell carcinoma of the nail unit

Squamous cell carcinoma (SCC) of the nail apparatus is a rare malignant tumor that usually originates underneath the nail plate and grows slowly with possible bone invasion. The etiology remains unknown, although a strong association with different conditions, such as high-risk human papillomavirus (HPVs), trauma, or radiation exposure has been demonstrated. Nail SCC is called "the great mimicker nail tumor" because different clinical presentations may coexist, resembling benign or malignant nail lesions. For this reason, there is often a significant delay between the onset of nail SCC and the diagnosis. Clinical manifestation includes onycholysis and erythema, while in the advanced stages nail ulceration can be observed. The association with pain, swelling, and inflammation usually indicates an invasive SCC with involvement of the underlying bone. Metastasis is rare but possible with involvement of lymph nodes. A multidisciplinary approach to assessment, management, and follow-up is advised. Using careful examination and modern diagnostic methods, including onychoscopy, biopsy, and histopathology, will help identify SCC and prevent the invasive progression. X-ray is important to investigate the bone invasion to determine the best surgical approach that will have satisfying cosmetic and functional outcomes. Nevertheless, local excision with sufficient surgical margins, best if using Mohs surgery, is usually sufficient and superior to amputation of the distal phalanx. This review aims to highlight the correct approach in suspected SCC of the nail unit.

Mohs micrographic surgery for nail unit tumours: an update and a critical review of the literature

Mohs micrographic surgery (MMS) is a good treatment option for epithelial neoplasms, especially when localized in areas where tissue conservation is crucial, such as the nail unit (NU). MMS is a method of radical excision offering high cure rates due to the margin control and functional preservation. Our aim is to provide a review on the use of MMS for the treatment of the most common nail tumours. We revised the current literature on the use of MMS to treat malignant neoplasms (Bowen's disease, squamous cell carcinoma, melanoma, basal cell carcinoma, keratoacanthoma, carcinoma cuniculatum) and benign neoplasms (onychomatricoma and glomus tumour). MMS represents a successful surgical option for nail tumours, firstly in terms of tissue conservation: the NU anatomy is complex and the preservation of the component structures is imperative for its functionality. Secondly, due to the surgical radicality, which is essential not only for the clearing of malignant tumours, but also for benign cases, in order to reduce recurrences. Although a conservative treatment of NU melanoma with MMS has been proposed, in our experience, the conservative approach with functional surgery is a good option for the treatment of non-invasive melanoma (in situ and Ia).