Bowen disease of the nail unit: a retrospective study of 12 cases and their association with human papillomaviruses

Nails in older adults

As the world's population of adults greater than 60 years old continues to increase, it is important to manage nail disorders that may impact their daily lives. Nail disorders may have significant impact on quality of life due to decreased functionality, extreme pain, or social embarrassment. In this review, we discuss nail disorders affecting older patients, including physiologic, traumatic, drug-induced, infectious, environmental, inflammatory, and neoplastic conditions. Diagnosis of these conditions involves a detailed history, physical examination of all 20 nails, and depending on the condition, a nail clipping or biopsy and/or diagnostic imaging. Nails grow even more slowly in older adults compared to younger individuals, and therefore it is important for accurate diagnosis, and avoidance of inappropriate management and delay of treatment. Increased awareness of nail pathologies may help recognition and management of nail conditions in older adults.

Update on Squamous Cell Carcinoma of the Nail Unit: An Human Papillomavirus-Associated Condition

Background

Squamous cell carcinoma (SCC) and SCC in situ (Bowen's disease) are the most common malignancies of the nail unit. They are frequently seen in men over 50 and most commonly affect the fingers. The role of high-risk human papillomavirus (HPV) infection has been identified as a key contributor to the development of nail unit SCC.

Summary

In this review, we aimed to summarize the current state of our understanding of how HPV contributes to nail unit SCC, the role of genitodigital transmission of HPV, and the clinical features of HPV-associated nail unit SCC. We also review current advances in the treatment of nail unit SCC, with a focus on the potential role of HPV vaccination in the treatment and prevention of nail unit SCC.

Key Messages

Nail unit SCC should be recognized as an HPV-associated disease. HPV vaccination may represent a non-surgical modality for the management of these challenging malignancies in the appropriate clinical setting.

Basic Concepts in Nail Pathology

ABSTRACT

Understanding nail pathology is complex for general pathologists and even for those dermatopathologists who do not receive many nail samples in their laboratories. In this article, we attempt to review some of the primary entities in nail pathology with the aid of modern interpretations of nail histology and embryology. We also provide diagrams that can aid in comprehending this field of pathology.

High-risk mucosal human papillomavirus-associated squamous cell carcinoma of the fingers presents distinctive clinicopathological characteristics and outcomes: a bicentric retrospective study

BACKGROUND

High-risk mucosal human papillomavirus (HR-HPV) seems to play a role in cutaneous squamous cell carcinoma (cSCC), particularly in nail tumours, where genitodigital transmission has been suggested. The role of HR-HPV in nonungual cSCC of the finger needs to be clarified.

AIM

To evaluate the prevalence, clinicopathological characteristics, surrogates and outcomes of HR-HPV in cSCC of the finger.

METHODS

This was an observational bicentric study including patients with an excised in situ or invasive cSCC located on the finger. Differences in HR-HPV and non-HR-HPV tumours were evaluated.

RESULTS

Forty-five patients (45 tumours) were included. HR-HPV was detected in 33% of cases (22% HPV type 16). The mean age was lower in patients with HR-HPV than in those with non-HR-HPV (62·4 vs. 81·1 years, P = 0·001). HR-HPV tumours were smaller (10 mm vs. 15 mm, P = 0·07) and more frequently intraepidermal (60% vs. 20%, P = 0·004). The absence of elastosis (P = 0·030) and inflammation (P = 0·026) and the presence of basaloid morphology (P = 0·003) were surrogates of HR-HPV detection. Mean p16 positivity was 61% in HR-HPV and 36% in non-HR-HPV tumours (P = 0·061). Recurrence after surgery was more common in HR-HPV tumours (58% vs. 34%), although this was not statistically significant. HR-HPV was detected in 27% of the nonungual tumours.

CONCLUSION

HR-HPV-associated cSCC of the finger appears in younger patients, is smaller and is less infiltrative than non-HR-HPV tumours. The presence of a basaloid morphology and the absence of elastosis and inflammation could be used as markers for HR-HPV detection. The high prevalence of HR-HPV in nonungual cSCC suggests its aetiopathogenic role in these tumours.

Squamous Cell Carcinoma in Situ of the Nail Unit: Current Evidence and Recommendations for Patient Centered Treatment

Squamous cell carcinoma in situ of the hand and nail is an infrequent tumor but represents the majority of hand and nail malignancies. While the conventional treatments of invasive nail unit squamous cell carcinoma include Mohs micrographic surgery, wide local excision, or distal digit amputation, no standardized management paradigm for in situ disease exists and the necessity of surgical options is debated. This review aims to discuss the most commonly reported treatment methods and critically assess relevant management considerations in order to facilitate appropriate treatment decisions for nail unit SCCis across dermatologic practice settings. Assessment of the current literature reveals insufficient evidence to determine a standardized treatment for nail unit squamous cell carcinoma in situ. Rather, management is greatly impacted by multiple factors including the presence of subungual involvement, surgical candidacy, importance of curative treatment, and patient preferences regarding cosmesis and function versus cure. When cure is desired, Mohs micrographic surgery is the treatment of choice in most cases. In the setting of desired curative intent, but poor surgical candidacy, radiotherapy may be effective and provide a reasonable chance of functional and cosmetic preservation. Other methods including photodynamic therapy, electrodesiccation and curettage, cryotherapy, and intralesional chemotherapeutics may be appropriate in specific circumstances, but are generally limited by lack of evidence or impracticalities. Lastly, observation with palliation may be appropriate when considering exceedingly rare disease-related mortality.

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.

Polydactylous Squamous Cell Carcinoma of the Nail Unit: A Structured Review of the Literature

Squamous cell carcinoma of the nail unit (SCCNU) is a rare neoplastic condition that involves multiple digits (polydactylous SCCNU) in only 3.9% of cases. Here, we report a case of polydactylous SCCNU and perform a comprehensive review of MEDLINE and Embase to collate 44 cases of polydactylous SCCNU reported to date. Polydactylous patients were younger on average (48 to 61-63 years) and had a longer diagnostic delay (44 vs 35.1 months) compared with reported monodactylous cases. Human papillomavirus (HPV) positivity was observed in 49% of cases, and the most common serotypes noted were 16 (25.8%), 73 (16.1%), 58 (9.7%), 18 (6.5%), and 33 (6.5%). Twenty percent of the cases were in immunosuppressed individuals who had a statistically significant lower age at diagnosis (39.33 years vs 51.12 years; P = .01) and diagnostic delay (2.50 months vs 132.46 months, P = .04). Patients with HPV positivity had a lower age at diagnosis (43.74 years vs 53.29 years, P = .04). Environmental exposures noted to be associated with polydactylous disease included X-rays, paint/solvents, soluble oils, and stagnant water. This comprehensive literature review serves to characterize polydactylous SCCNU and distinguish the differences in its characteristics to improve diagnosis and clinical recognition.

The role of reflectance confocal microscopy in the diagnosis and management of squamous cell carcinoma in situ treated with photodynamic therapy

BACKGROUND

Reflectance confocal microscopy (RCM) is increasingly used for noninvasive in vivo diagnosis of skin cancers. We seek to determine if RCM is useful for the diagnosis and follow-up of squamous cell carcinoma in situ (SCCIS) posttreatment to document clearance.

METHODS

A pilot prospective study enrolled 10 patients with a total of 11 SCCIS lesions. Clinical, confocal, histological features and fluorescence diagnosis (FD) were recorded pre- and posttreatment.

RESULTS

Four SCCIS lesions underwent RCM imaging prior to biopsy, while 11 SCCIS lesions were followed up with RCM imaging. Clinical features of persistent SCCIS post-PDT in four out of 11 follow-up cases were confirmed with RCM and FD. There were no RCM features of SCCIS in seven lesions which were clinically cured. All eight (four new SCCIS and four follow-up) cases displayed atypical honeycomb pattern. Two cases (25%) showed numerous epidermal dendritic cells, while small bright refractive cells were present in the epidermis in two lesions (25%). Round blood vessels in the superficial dermis were seen in four lesions (50%), while three lesions (37.5%) showed dermal inflammatory cells.

CONCLUSION

There was good correlation between histological and confocal features in patients who underwent RCM imaging prior to biopsy. RCM may be a complementary tool in diagnosing SCCIS and to monitor response to nonsurgical treatment by avoiding unnecessary biopsies especially in lesions with persistent residual postinflammatory erythema.

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.

High-risk human papillomavirus in a child with digital pigmented Bowen's disease: Case report and dermoscopic findings

Squamous cell carcinoma in situ, also known as Bowen's disease (BD), is a skin malignancy most commonly seen in middle-aged and elderly adults. Pediatric BD is rare and can be a diagnostic challenge for physicians. Digital BD has largely been associated with human papilloma virus. We report an immunocompetent 11-year-old girl with periungual pigmented BD induced by high-risk human papilloma virus.

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).

Important malignant and new nail tumors

The nail apparatus is an integral part of the functional unit of the digital tip. Although overall uncommon, all cells and tissues occurring in this area can give rise to neoplastic lesions. Given the special anatomical location, such tumors frequently show morphological and symptom-related differences compared to similar lesions located elsewhere on the skin. Though particularly threatening, there is often a substantial delay in the diagnosis of Bowen's disease, ungual squamous cell carcinoma, and melanoma. Nevertheless, local excision with sufficient surgical margins is usually sufficient and superior to amputation of the distal phalanx. In recent years, a number of nail-specific tumors have been described. Tumors such as onychomatricoma, onychocytic matricoma, onychocytic carcinoma, and onychopapilloma originate from the nail matrix. Onycholemmal cysts, onycholemmal horn, and the proliferating onycholemmal tumor are characteristic nail bed tumors. Onycholemmal carcinoma is a slowly growing low-grade malignancy. Using modern diagnostic methods, careful examination - including biopsy and histopathology - of nail changes not responding to conservative treatment will help identify nail-specific neoplasms and prevent the progression of malignant nail tumors.

Dermoscopy in the Evaluation of Nail Disorders

Nail dermoscopy was initially used only in the assessment of nail pigmentation, but now it is widely utilized for the evaluation of many nail disorders. In daily practice, dermoscopy may confirm clinical diagnoses and guides in the management of nail diseases and treatments, permitting a better visualization of symptoms. Dry dermoscopy is required for evaluation of the nail plate surface, while gel as an interface is necessary for assessment of nail pigmentation and onycholysis, as well as for the evaluation of the distal nail margin. In this review, we describe the dermoscopic features of the most important nail disorders, looking at the different areas of the nail. Dermatoscopic changes that usually accompany specific nail diseases are also reviewed.