Ungual and periungual human papillomavirus–associated squamous cell carcinoma: A review

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.

Squamous cell carcinoma of the nail apparatus: Histopathology and immunohistochemistry correlation study

BACKGROUND

Nail squamous cell carcinoma (NSCC) is the most frequent ungual malignant tumor, but its incidence remains low. The histopathological description is sparse. We aim to characterize NSCC histopathological aspects, search for a correlation with clinical subtypes, and investigate immunohistochemistry expression of p16, p53, and Ki67.

METHODS

This retrospective study collected NSCC diagnosed in our dermatology department between 2007 and 2021. The histopathological features were correlated with the clinical signs and immunohistochemistry.

RESULTS

A total of 48 patients were included, and immunohistochemistry was available for 36 of them. Two histopathological patterns became prominent: a blue-basaloid type characterized by koilocytosis (p < 0.001), and a pink-keratinizing type. Mean ages were similar when comparing basaloid and periungual versus keratinizing and subungual (p < 0.001). p16 was positive in 31 of 36 cases: 18 basaloid and 13 keratinizing (p = 0.167). p53 and Ki67 were all abnormal.

CONCLUSIONS

Our study described two histopathological NSCC subtypes and associated them with the two clinical subtypes: the blue-basaloid type, HPV-induced, in situ, of periungual localization in younger males; and the pink-keratinizing type, non-HPV-induced, invasive, of subungual site, in elderly. Immunohistochemistry was not contributing on its own, but p16 positivity associated with basaloid histopathological profile helps support HPV etiology.

A case report of squamous cell carcinoma mimicking interdigital intertrigo

Squamous cell carcinoma (SCC), also known as epidermoid carcinoma, represents the most common malignant tumor affecting the nails. A 60-year-old tailor with no significant medical history presented with a three-year history of macerated skin between the toes, previously treated with a topical antifungal. Dermatological examination revealed a verrucous, infected ulceration with infiltrated and hyperkeratotic edges, characterized by a whitish, fissured base. This lesion in the fourth interdigital space and extended onto the dorsal surface of the foot without any other associated symptoms. The clinical diagnosis identified it as a neoplastic ulceration. An initial biopsy found keratoacanthoma but showed no malignant features. However, follow-up biopsy at our department revealed moderately differentiated SCC. Surgical resection was successful in treating our patient. Diagnostic errors due to insufficient understanding of the pathology and inadequate biopsy methods contribute to the progression of SCC. Surgery is the main treatment for such malignant tumors.

Ultrasound of Nails: Why, How, When

Nail disorders are frequently a challenge to diagnose correctly only based on clinical findings. Moreover, biopsies may leave scars due to damage to the nail matrix. Currently, high-frequency ultrasound (HFUS) with probes >15 MHz is the first-choice imaging technique to study the nail. Compared with other imaging tests such as computed tomography and magnetic resonance imaging, HFUS has the advantage of high-resolution imaging of the nail apparatus without exposure to radiation, contrast media, and the risk of claustrophobia of these other expensive imaging methods. Notably, the axial spatial resolution of HFUS is higher than computed tomography and magnetic resonance imaging; therefore, it can better discriminate the anatomical alterations. Our objective is to review the main applications of HFUS of the nail through literature analysis and illustration of cases of the most frequent pathologies found in our experience, exemplifying why, how, and when HFUS could help diagnose nail diseases.

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.

Cutaneous Squamous Cell Carcinoma: An Updated Review

Representing the second most common skin cancer, the incidence and disease burden of cutaneous squamous cell carcinoma (cSCC) continues to increase. Surgical excision of the primary site effectively cures the majority of cSCC cases. However, an aggressive subset of cSCC persists with clinicopathological features that are indicative of higher recurrence, metastasis, and mortality risks. Acceleration of these features is driven by a combination of genetic and environmental factors. The past several years have seen remarkable progress in shaping the treatment landscape for advanced cSCC. Risk stratification and clinical management is a top priority. This review provides an overview of the current perspectives on cSCC with a focus on staging, treatment, and maintenance strategies, along with future research directions.

A pilot study of p53 immunohistochemistry in atypical squamous lesions, using a vulvar scoring system

BACKGROUND

Histopathologic overlap between cutaneous squamous cell carcinoma (cSCC) and its indolent mimics likely leads to the overdiagnosis of cSCC.

OBJECTIVE

To perform a pilot study of the p53 immunohistochemical scoring system developed on vulvar squamous lesions in cSCC.

METHODS

The consistency and reliability of p53 immunostaining using a scoring system developed on vulvar cases, as compared with TP53 genomic sequencing, was studied in an initial cohort of 28 cutaneous cases. p53 labeling was further assessed in an additional 63 cases of atypical squamous lesions, including 20 atypical squamous lesions classified by the authors as benign, 22 cases diagnosed as cSCC without high-risk features, and 21 cases of high-risk cSCC (cSCC-HR).

RESULTS

The concordance of p53 labeling and TP53 sequencing was 82.1%. Four positive patterns of p53 mutation were identified: basal, parabasal/diffuse, null, and cytoplasmic. p53 positivity in atypical, benign squamous lesions (10%) was significantly lower than that of low-risk cSCC (63.6%, p = 0.0004) or cSCC-HR (90.5%, p < 0.0001). p53 positivity in low-risk cSCC versus cSCC-HR was not statistically significant (p = 0.07).

CONCLUSION

p53 Labeling may be a helpful biomarker to support the diagnosis of cSCC and distinguish cSCC from atypical but benign mimics.

Multiple Bowen's disease on the finger associated with human papillomavirus type 34

Human papillomavirus (HPV) infection has been suggested as a potential risk factor for Bowen's disease. Here, we report a case of a 40-year-old man with Bowen's disease on the finger showing a discontinuous skip lesion, in which HPV-34 was detected. Our case is a reminder that the possibility of multiple lesions must be considered when Bowen's disease occurs on the finger.

Microwave therapy for the treatment of plantar warts

BACKGROUND

Plantar warts, or verrucae plantaris, are common lesions causing considerable pain during weightbearing activity. Although current treatment modalities have low success rates, microwave therapy has been introduced as a promising intervention. This study aimed to determine the effectiveness of microwave therapy for the treatment of plantar warts and to determine the clinical factors associated with plantar wart resolution.

METHODS

A retrospective analysis of 150 plantar warts from 45 patients treated with microwave therapy was undertaken. Binomial regression was conducted to explore clinical characteristics (age, gender, immunosuppression, impaired healing, multiple vs single wart, location of lesion, lesion diameter) associated with lesion resolution.

RESULTS

Of the total 150 plantar warts treated with microwave therapy, 125 (83.3%) warts resolved and 25 (17%) warts did not resolve. The mean (SD) total treatment sessions for resolved lesions was 2.8 (1.0). Decreasing age (P = 0.046) was the only clinical characteristic associated with resolution.

CONCLUSIONS

This retrospective study has shown that plantar warts may be resolved with two to three sessions of microwave therapy, which may be more successful in younger populations.

Advances in cutaneous squamous cell carcinoma

Human malignancies arise predominantly in tissues of epithelial origin, where the stepwise transformation from healthy epithelium to premalignant dysplasia to invasive neoplasia involves sequential dysregulation of biological networks that govern essential functions of epithelial homeostasis. Cutaneous squamous cell carcinoma (cSCC) is a prototype epithelial malignancy, often with a high tumour mutational burden. A plethora of risk genes, dominated by UV-induced sun damage, drive disease progression in conjunction with stromal interactions and local immunomodulation, enabling continuous tumour growth. Recent studies have identified subpopulations of SCC cells that specifically interact with the tumour microenvironment. These advances, along with increased knowledge of the impact of germline genetics and somatic mutations on cSCC development, have led to a greater appreciation of the complexity of skin cancer pathogenesis and have enabled progress in neoadjuvant immunotherapy, which has improved pathological complete response rates. Although measures for the prevention and therapeutic management of cSCC are associated with clinical benefit, the prognosis remains poor for advanced disease. Elucidating how the genetic mechanisms that drive cSCC interact with the tumour microenvironment is a current focus in efforts to understand, prevent and treat cSCC.

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.

Cutaneous Squamous Cell Carcinoma Masquerading as a Verruca: Case Report and Literature Review of Coexisting Wart and Invasive Squamous Cell Carcinoma on the Hand

A verruca is a human papillomavirus-associated infection of the mucosal or cutaneous epithelium. Cutaneous squamous cell carcinoma is an invasive skin cancer that commonly occurs on sun-exposed locations. Human papillomavirus infection has also been demonstrated to be a cocarcinogen, along with ultraviolet radiation, in the pathogenesis of cutaneous squamous cell carcinoma. A 63-year-old man presented with a verrucous nodule of nine months duration on his dorsal left hand. The clinical differential diagnosis included a wart and a small punch biopsy of the lesion showed a verruca. The lesion continued to enlarge and the possibility of a squamous cell carcinoma was considered. A second larger shave biopsy of the residual lesion was performed and the microscopic evaluation revealed not only a benign verruca at the lateral portion of the nodule but also an invasive squamous cell carcinoma in the center of the lesion. We hypothesize that the patient's human papillomavirus-associated wart may have contributed to the development of his cutaneous squamous cell carcinoma. Therefore, in an individual with a clinically suspected or biopsy-confirmed wart that persists despite lesion-directed treatment, additional evaluation of the lesion should be considered to assess whether an alternative or concurrent tumor, such as a cutaneous squamous cell carcinoma, is present.

Treatment Options and Outcomes for Squamous Cell Carcinoma of the Nail Unit: A Systematic Review

BACKGROUND

Nail squamous cell carcinoma (nSCC) is the most common nail unit malignancy. However, no studies to date have evaluated treatment options for nSCC based on recurrence data while controlling for invasion.

OBJECTIVE

To identify temporal trends in nSCC treatment modalities and compare treatment outcomes based on invasion.

METHODS AND MATERIALS

The authors performed a systematic review of articles published on PubMed, MEDLINE, and Scopus from inception to April 2020 reporting treatment of nSCC. The primary outcome was disease recurrence.

RESULTS

Reports of nSCC treatments have increased in the past decade. Mohs micrographic surgery (MMS) is the most common treatment reported overall. The lowest recurrence rates for in situ nSCC were seen with wide surgical excision (WSE) and MMS. For invasive disease, the recurrence rates were lowest with amputation, MMS, and WSE.

CONCLUSION

Complete surgical excision of nSCC with either WSE or MMS is associated with lower recurrence rates than limited excision and nonsurgical therapies, regardless of degree of invasion. The prognostic significance of in situ versus invasive disease remains unclear. Confirmation of complete excision may improve outcomes. Digital amputation is indicated for nSCC with bone invasion. Prospective studies and randomized controlled trials are needed to directly compare surgical modalities for nSCC.

Proliferating Onychomatricoma. Clinical, Dermoscopical, and Pathologic Features of Onychomatricoma New Variant Resembling Onycholemmal/Squamous Cell Carcinoma

Proliferating onychomatricoma is a new challenging variant of onychomatricoma that can clinically and histologically mimic squamous cell carcinoma/onycholemmal carcinoma. This is a retrospective case series study of the clinicopathologic and dermoscopic features of 6 patients with a pathologic diagnosis of proliferating onychomatricoma, which was conducted in the dermatology and dermatopathology departments of 2 university hospitals and a private nail's dermatology consultation. The clinical, histological, and immunohistochemical features and follow-up of 6 patients with proliferating onychomatricoma were analyzed; we compare our finding with 6 cases of conventional onychomatricoma. The female-to-male ratio was 1:1 with involvement of fingers in 4 and toe in 2. Among the symptoms were verrucous lesion simulating squamous cell carcinoma, nail thickening, periungual erythema, and pain; symptom duration ranged from 5 to 8 years. Clinical, dermoscopical en face free-margin view, and nail-clipping histologic findings reveal a nail wall-like pattern with pitting. Intraoperative, noncontact, polarizing, light dermoscopy was available in 1 case and showed the typical signs of onychomatricoma (OM). Histologically, all cases showed a well-differentiated, infiltrative, squamous, proliferative lesion exhibiting a lobulated and cystic pattern of growth in the dermis. Abrupt keratinization reminiscent of trichilemmal keratinization, but corresponding in fact to keratogenous spheres, was noted as well as a dysmaturative epithelial pattern. No atypical cytomorphological changes were found. Proliferating onychomatricoma is a new variant of onychomatricoma, which can be misdiagnosed as squamous cell carcinoma/onycholemmal carcinoma; its proper recognition may minimize morbidity associated with inappropriate treatment. Proliferating OM can be differentiated from conventional OM clinically by a free-edge wall-like pattern and on histology of nail clipping by the relatively small size of the cavities. Dermoscopic and nail clipping attributes as free-edge honeycomb-like cavities associated with conventional OM are well established and permit a diagnosis of OM without an invasive nail biopsy. The free-edge wall-like pattern is a distinct new dermoscopic and nail-clipping pattern that should raise for the others onychogenic neoplasms and prompt the clinician to obtain a biopsy specimen. In addition to proliferating OM, the differential diagnosis includes a micropapilliferum variant of OM, onychocytic matricoma, and onychocytic carcinoma.

Mucocutaneous Squamous Cell Carcinoma in a Yucatan Minipig

Minipigs are commonly utilized in dermal toxicology studies, necessitating documentation of background findings, including neoplastic lesions. We describe a case of a Yucatan minipig with a squamous cell carcinoma at the mucocutaneous junction of the lip. The neoplasm appeared grossly as a slightly raised area of skin with ulceration. Histologically, there were nests and trabeculae of neoplastic squamous epithelial cells undergoing keratinization. Multifocally, rafts of these cells were within lymphatic vessels. Squamous cell carcinoma has not previously been reported in Yucatan or other laboratory minipigs, however, has been reported uncommonly in nonlaboratory pot-bellied pigs. Although squamous cell carcinoma has been associated with ultraviolet exposure or papillomavirus in various species, this was unable to be confirmed in this case.

Nail Tumors

This article describes nail tumors and their clinical features, biologic behavior, and treatment. Tumors included are onychopapilloma, onychomatricoma, periungual fibromas/fibrokeratomas, glomus tumors, subungual exostosis, myxoid cysts, and squamous cell carcinoma.

Squamous Cell Carcinoma Arising in Ungual Lichen Planus: Report and Review

Background

Lichen planus (LP) can lead to severe scarring of the nail unit leading to anonychia. There are very few reports of squamous cell carcinoma (SCC) occurring in the lesions of ungual LP.

Objective

The aim of this study was to revise the previously reported cases of SCC appearing in ungual LP and to present a new case.

Methods

A PubMed search was performed with the terms "nail lichen planus" and "squamous cell carcinoma." Reported cases as well as a new case were depicted in a table.

Results

Only 2 indexed articles reporting 3 cases were found. All patients suffered of long-lasting scarring ungual LP.

Conclusions

The occurrence of SCC in nail LP is rare. LP is not "premalignant" per se, but SCC might rarely arise in LP scars.

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.

Subungual Squamous Cell Carcinoma in a Patient with Psoriasis

Subungual squamous cell carcinoma (SCC) is a rare malignant tumour with an indolent course and unknown aetiology. It is usually misdiagnosed as a benign lesion, resulting in delayed treatment. Although psoriasis is not a precancerous skin condition, the treatment modalities cyclosporine and psoralen with ultraviolet A (PUVA) might increase the risk of developing cutaneous SCC, although a relationship has not been confirmed. We describe a patient with psoriasis who had been treated with cyclosporine and PUVA 6 years previously. He developed back SCC 2 years later, a subungual skin lesion after another 2 years and presented to us 1 year later, when nail elevation and biopsy revealed SCC.

LEARNING POINTS

Subungual squamous cell carcinoma (SCC) is often misdiagnosed as a benign condition so most cases are invasive by the time of diagnosis; nail elevation and biopsy are recommended in all suspicious cases.Although psoriasis is not an independent risk factor for subungual SCC, the cyclosporine and PUVA used to treat psoriasis are risk factors for cutaneous SCC.The aetiology for subungual SCC is still unclear, but it should be suspected in patients with psoriasis and a suspicious presentation.

Structure, Genome, Infection Cycle and Clinical Manifestations Associated with Human Papillomavirus

A small, non-enveloped, obligatory parasite, Human papillomavirus (HPV) is known to be the cause of a range of malignancies. These entail benign infections like genital warts as well as malignant, life-threatening conditions such as cervical cancer. Since a very high mortality rate is associated with HPV caused cancers (cervical cancer is a 2nd leading cause of death caused due to cancer among women globally), there is an escalating need to understand and search for ways to combat such medical conditions. Under the same light, the given article provides an insight into the world of this versatile pathogen. Distinct aspects related to HPV have been discussed here. Emphasis has been laid upon the composition, function and assembly of capsid proteins (structural studies) and various genetic elements and their gene products (genomic studies). The essence of the mechanism behind the development of persistent infection and modes responsible for the transmission of the infectious particles has been briefly covered. Finally, the review outlines various infections and diseases caused by HPV with a major focus on their clinical and histological manifestations.

Verrucous Carcinoma of the Nail Bed: A New Case

Verrucous carcinoma (VC) of the nail bed is a rare variant of squamous cell carcinoma that is often misdiagnosed as a benign condition. The clinical presentation of this tumor is very similar to that of warts or onychomycosis hence the delayed appropriate treatment. Its association with human papillomavirus (HPV) infection has rarely been reported. The treatment of VC of the nail unit depends on the extent of the lesion and the presence or the absence of bone. We here report an unusual case of VC of the nail bed of the left big toe in a man associated with HPV53 infection that had been mistaken for a wart for 1 year. The condition was treated by ray amputation.

High-Risk Human Papillomavirus E6/E7 mRNA Is Rarely Detected in Nonanogenital Cutaneous Squamous Cell Carcinoma: An RNA In Situ Hybridization-Based Tissue Microarray Study

High-risk human papillomavirus (HR-HPV) is known to play an oncogenic role in squamous cell carcinoma (SCC) at certain anatomical sites, namely the uterine cervix, oropharynx, and anogenital skin. However, the association between HR-HPV and nonanogenital cutaneous SCC (CSCC) remains controversial. In this study, we addressed this controversy by performing HR-HPV E6/E7 mRNA in situ hybridization (ISH) on 243 CSCC samples. A cocktail of E6/E7 mRNA ISH probes, recognizing 18 HR-HPV genotypes, was applied to a tissue microarray of paraffin-embedded sections of 154 invasive and 89 in situ CSCC specimens. The anatomical sites of CSCC included the head and neck (n = 100), extremities (n = 100), trunk (n = 25), and anogenitalia (n = 18). We also investigated the correlation between the p16 expression and HR-HPV status by immunohistochemistry. The results of HR-HPV E6/E7 mRNA ISH showed that 5.8% (14/243) of all CSCC samples were positive for HR-HPV, including 66.7% (12/18) of the anogenital and only 0.9% (2/225) of the nonanogenital CSCC samples (P < 0.01). For the detection of diffuse p16 expression by immunohistochemistry, the sensitivity was 100% (14/14 HR-HPV-positive CSCC samples), and the specificity was 72.1% (165/229 HR-HPV-negative specimens). Thus, HR-HPV E6/E7 mRNA was rarely detected in nonanogenital CSCC, making it unlikely that the virus contributes to the pathogenesis of this malignancy. In addition, p16 immunoreactivity has a limited value as a surrogate marker for transcriptionally active HR-HPV in nonanogenital CSCC.

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 mucosal HPV types associated with squamous cell carcinoma on the nose tip in an immunocompetent young man

The oncogenic role of high-risk HPV in anogenital, head and neck, and cervical cancer is well recognized, but not in skin cancer in the general population. Some authors have demonstrated their appearance mainly on the hands and feet, particularly in the area of the nail bed, which could be due to contamination with HPV types from anogenital regions. Here, we describe a case of genital HPV associated with SCC on the nose tip in an immunocompetent young man, which was confirmed by histopathological findings and in situ hybridization. The importance of this report is to highlight the potential role of HPV in the etiology of skin cancer in an immunocompetent individual.

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.

Squamous Cell Carcinomas in Two Cases of Nail Lichen Planus: Is There a Real Association?

Lichen planus (LP) is a chronic inflammatory disease that affects the skin and oral mucosa. Although its etiology is unknown, its potential for cancerization has been confirmed. We herein report the cases of a brother and sister, both with a 15-year history of nail lichen planus of the fingers and toes, who developed squamous cell carcinomas of the nail bed and matrix. This article shows the potential for malignant transformation in lichen planus disease and highlights the importance of periodic clinical follow-up.

Marjolin's squamous cell carcinoma of the hallux following recurrent ingrown toenail infections

Marjolin's squamous cell carcinoma (SCC) affecting the toe is rare. Due to resemblance with benign conditions it can often result in misdiagnosis. We report a case of Marjolin's SCC affecting the proximal hallux in a patient with recurrent ingrown toenail infections. A 58-year-old woman with a background of wedge resections for ingrown toenail and distal phalanx amputation for osteomyelitis presented with pain and hyperkeratotic raised ulcer around the proximal phalanx. MRI scan revealed soft tissue mass infiltrating the proximal phalanx with biopsies confirming a SCC. The patient underwent first ray amputation and made a good clinical recovery and remains disease free. Due to clinical similarities with benign conditions, awareness of Marjolin's SCC as a potential diagnosis when treating patients with recurrent ingrown toenail is imperative. We recommend patients with recurrent ingrown toenail or ulceration with a background of chronic infection have biopsies performed to exclude potential malignancy.

Surgical Treatment of Subungual Squamous Cell Carcinoma by Wide Excision of the Nail Unit and Skin Graft Reconstruction: An Evaluation of Treatment Efficiency and Outcomes

Importance

The best surgical treatment modalities for subungual squamous cell carcinoma (SUSCC) without bone invasion need to be determined. The limited available data on Mohs micrographic surgery do not demonstrate its use as a standard procedure. A previous study in a limited series of patients has shown that wide surgical excision of the nail unit was associated with a low rate of recurrence.

Objectives

To confirm the efficiency of wide surgical excision of the nail unit with full-thickness skin graft reconstruction on a series of patients with SUSCC with an extended follow-up and to evaluate short- and long-term postoperative morbidity and patient satisfaction.

Design, Setting, and Participants

A consecutive series of 55 patients with biopsy-proven SUSCC without bone invasion treated by wide surgical excision of the nail unit followed by full-thickness skin graft reconstruction from January 1, 2000, to August 31, 2012 were included. After a minimum follow-up of 5 years, the recurrences were collected from the referring physicians. Statistical analysis was conducted from January 1 to June 30, 2016.

Main Outcomes and Measures

Demographic data, pathologic characteristics of tumors, postoperative follow-up, and recurrences were collected from medical records. Patients' satisfaction with surgery, quality of life, and delayed postoperative morbidity (functional outcome and sensory disorders) were assessed from a questionnaire mailed to patients and physicians.

Results

Among the 55 patients (23 women and 32 men; mean age, 64 years), the mean follow-up was 6.6 years (range, 5.0-11.2 years), with a minimum follow-up of 5 years. Fifty-two questionnaires (95%) were returned. Two recurrences were observed. Minor early postoperative complications, such as graft infection and delayed wound healing, were seen in 6 patients; 8 patients experienced severe pain. Late postoperative complications included hypersensitivity to mechanical shocks (39 of 51 patients [76%]), mildly increased sensitivity to cold (38 of 51 patients [75%]), loss of fine touch sensation (17 of 35 patients [49%]), and epidermal inclusion cysts (9 of 51 patients [18%]). Most patients were very satisfied with cosmetic and global outcomes of the surgery.

Conclusions and Relevance

Total excision of the nail unit followed by a full-thickness skin graft is a safe and efficient treatment for SUSCC without bone involvement, with satisfying cosmetic and functional outcomes.

Human papillomavirus 16 is an aetiological factor of scrotal cancer

Background:

Squamous cell scrotal carcinoma (SCSC) is an infrequent skin cancer associated historically with occupational carcinogens. Human papillomavirus (HPV) DNA has been associated with SCSC but there is no definitive proof of its oncogenic role.

Methods:

Human papillomavirus-DNA and –E6*I mRNA were analysed in six invasive histologically typed SCSC. LCM-PCR was used to localise HPV DNA to tumour cells. P16^INK4aand p53 expression were studied by immunohistochemistry.

Results:

In three warty or basaloid SCSC HPV16-DNA and E6*I-mRNA were detected. LCM-PCR confirmed HPV16 was in p16^INK4a-positive malignant cells. However, of three usual-type SCSC, all were HPV-negative and two expressed p53 protein but not p16^INK4a.

Conclusions:

Human papillomavirus 16 was present in tumour cells and oncogenically active in basaloid and warty SCSC, whereas usual SCSC was HPV-negative and showed immunostaining, suggesting p53 mutation. The dual pathways of oncogenesis and relation between histological type of SCSC and HPV are similar to that in penile cancers.

Nail neoplasms

Nail neoplasms include all tumors occurring in the nail or periungual apparatus tissue. While some nail tumors can be similar to tumors located on the skin, others are unique. Both benign and malignant lesions can affect the nail apparatus. In particular, early malignant tumors like melanoma and squamous cell carcinoma can present similarly to onychomycosis or benign melanonychia and frequently missed by clinicians. Therefore, physicians should be aware of nail structures and the characteristics of nail tumors. Our review covers the normal nail structure and the most common nail tumors from benign to malignant.

Subungual squamous cell carcinoma

Although subungual squamous cell carcinoma is rare, it is the most common primary malignant neoplasms in this location. The higher incidence occurs in the fingernails, but involvement of the toenails is also possible. Subungual squamous cell carcinoma often looks like other more common benign lesions, such as fungal infection, onychomycosis, or viral wart. These factors, together with a general lack of awareness of this disease among physicians, often result in delayed diagnosis. Therefore, it is underdiagnosed, with few reports in the literature. The authors present a case of a man with a diagnosis of subungual squamous cell carcinoma in the hallux, without bone involvement, which was submitted to the appropriate surgical treatment.

Subungual Squamous Cell Carcinoma: The Diagnostic Challenge and Clinical Pearls

Subungual squamous cell carcinoma is a rare entity and difficult to diagnose as its clinical presentation may resemble benign conditions. This case report highlights the need to maintain a high clinical index of suspicion, and recommends a practical approach for subungual conditions. Dermoscopy and a biopsy for histology are important adjuncts to clinch the diagnosis.

[Squamous cell carcinoma of the nail apparatus on the hallux without osseous involvement: study of a patient treated by amputation]

Le diagnostic tardif du carcinome épidermoïde de l'hallux a nécessité une amputation trans phalangienne proximale chez un patient âgée pris en charge en seconde main. C'est une lésion rare aux orteils qui peut mettre en jeu le pronostic fonctionnel du pied. Nous rapportons ce cas clinique dans le but de mettre en évidence les difficultés du diagnostic et les bases de l'amputation avec une revue de la littérature.