Digital squamous cell carcinoma and association with diverse high-risk human papillomavirus types

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.

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.

Defining Novel DNA Virus-Tumor Associations and Genomic Correlates Using Prospective Clinical Tumor/Normal Matched Sequencing Data

This study is the largest analysis of DNA viruses in solid tumors with associated genomics. To achieve this, a novel method for discovery of DNA viruses from matched tumor/normal next-generation sequencing samples was developed and validated. This method performed comparably to reference methods for the detection of high-risk (HR) human papilloma virus (HPV) (area under the receiver operating characteristic curve = 0.953). After virus identification in 48,148 consecutives samples from 42,846 unique patients, novel virus tumor associations were established by segregating tumor types to determine whether each DNA virus was enriched in each of the tumor types compared with the remaining cohort. All firmly established solid tumor-virus associations (eg, HR HPV in cervical cancer) were confirmed, and the novel associations discovered included: human herpes virus 6 in neuroblastoma, human herpes virus 7 in esophagogastric cancer, and HPV42 in digital papillary adenocarcinoma. These associations were confirmed in an independent validation cohort. HR HPV- and Epstein-Barr virus-associated tumors showed newly discovered genomic associations, including a lower tumor mutation burden. The study demonstrated the ability to study the role of DNA viruses in human cancer from clinical genomics data and established the largest cohort that can be utilized as a validation set for future discovery efforts.

A Call for Evidence-Based Conservative Management of Nail Unit Malignancies

SUMMARY

Nail unit squamous cell carcinoma and melanoma are the most common malignancies of the nail apparatus. Compared to their cutaneous counterparts, they are diagnosed later and perceived as more aggressive. This may result in overzealous management, including radiographic imaging with poor sensitivity and specificity, interventional nodal staging by sentinel lymph node biopsy, amputation over digit-sparing tumor resections, and elaborate reconstructions after tumor extirpation. In this review article, the authors evaluate the evidence behind several misconceptions in nail malignancy management and provide evidence-based guidance for more conservative care.

Squamous cell carcinoma in a digit of the hind limb with systemic metastasis in a 17-year-old female koala

We encountered a case of cutaneous squamous cell carcinoma (SCC) in a 17-year-old female koala at a zoo. A fragile, papillary, elevated mass was found on the third digit of the right hind limb. SCC was identified histopathologically: squamous cell-like polygonal tumor cells showed a nest-like growth pattern with epidermal down growth, central keratinization and necrotic foci, and invaded dermal connective tissues. Metastatic lesions were observed in various organs, including the lung and axillary lymph node: in the lung, multiple metastatic foci similar to the primary lesion, and in the axillary lymph node, individual polygonal tumor cells infiltrated the sinusoids. Immunohistochemistry revealed that the tumor cells were positive for proliferating cell nuclear antigen, which exhibited 32–33% of labeling indices in the tumor cells. To our knowledge, this is the first report of a case of SCC in a digit of a koala.

Squamous Cell Carcinoma of the Hand: A Retrospective Study in Immunosuppressed and Immunocompetent Individuals

BACKGROUND

Cutaneous squamous cell carcinoma (SCC) of the hand presents a treatment challenge because of the anatomical complexity of this location. Immunosuppressed patients are disproportionately affected by cutaneous SCC. Existing data on SCC of the hand are primarily presented in the orthopedic literature, and may thus be affected by referral bias.

OBJECTIVE

Characterization of epidemiology and treatment outcomes for hand versus nonhand cutaneous SCC in immunosuppressed versus immunocompetent patients, across all clinical departments.

MATERIALS AND METHODS

Single-institution retrospective cohort study of cutaneous SCC evaluated over 3 years and hand SCC over an additional 5 years.

RESULTS

A cohort of 522 hand SCC cases (1,746 total SCC) was ascertained among 1,064 patients, of whom 175 were immunosuppressed. Occurrence on the hand was more common for SCC arising in immunosuppressed versus immunocompetent patients (38% vs 24% of cases respectively). Hand SCC cases demonstrated balanced laterality and comparable spectra of differentiation regardless of immunosuppression. No cases of hand SCC metastasis were observed over greater than 2 years' mean follow-up, and digital amputation was only required in approximately 1% of hand SCCs.

CONCLUSION

In our cohort, assessment of hand SCC across all clinical departments suggests more favorable prognosis than reflected in the previous literature.

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.

HIV-Related Skin Disease in the Era of Antiretroviral Therapy: Recognition and Management

Antiretroviral therapy (ART) has revolutionized the treatment and prognosis of people living with HIV (PLHIV). With increased survival and improved overall health, PLHIV are experiencing dermatologic issues both specific to HIV and common to the general population. In this new era of ART, it is crucial for dermatologists to have a strong understanding of the broad range of cutaneous disease and treatment options in this unique population. In this review, we outline the most common skin diseases in PLHIV, including HIV-associated malignancies, inflammatory conditions, and infections, and focus on the role of ART in altering epidemiology, clinical features, diagnosis, and treatment of cutaneous conditions.

HPV73 a nonvaccine type causes cervical cancer

HPV73 is classified as possibly oncogenic. It is neither routinely evaluated in HPV screening, nor covered by any of the prophylactic vaccines. We sought to investigate the carcinogenic characteristics of HPV73. Molecular studies were performed on eight cervix cancer biopsy specimens containing HPV73 from a cross-sectional cancer cohort of 590 women referred to the National Cancer Institute in Rio de Janeiro, Brazil. Transcriptional activity of HPV73 was evaluated by detection of spliced transcripts of E6/E6* and E1^E4 in cDNA created from RNA isolated from fresh tissue. Disruption of viral E1 and E2 genes in the tumor DNA was assessed by overlapping PCR amplification. Evaluation of viral integration was performed using a customized capture panel and next-generation sequencing, and an in-house bioinformatic pipeline. HPV73 E6/E6* transcripts were found in 7/7 specimens with available RNA, and three also had HPV73 E1^E4 transcripts. Disruption of E1 and E2 genes was observed in 4/8 specimens. Integration of HPV73 sequences into the cancer cell genomes was identified in all cervix cancer tissues. These results provide evidence that HPV73 is an oncogenic virus that can cause invasive cervix cancer. With current molecular screening and HPV vaccination, not all cervix cancers will be prevented.

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.

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.

Low rate of detection of mucosal high-risk-type human papillomavirus in Korean patients with extragenital Bowen's disease and squamous cell carcinoma, especially in digital cases

Human papillomavirus (HPV) infection has been demonstrated in some of the nonmelanoma skin cancers as well as in precancerous lesions. Multiple infections of mucosal high-risk HPV may contribute to the onset of digital Bowen's disease through, if any, digital-genital transmission. We screened for the presence of the mucosal HPV DNA in patients with extragenital Bowen's disease (n = 30), squamous cell carcinoma (n = 11), bowenoid papulosis (n = 9), verrucous carcinoma (n = 1), actinic keratosis (n = 5), and basal cell carcinoma (n = 5). We used a PANArray HPV Genotyping Chip for high-risk and low-risk mucosal types. Genotyping data was confirmed using a conventional direct DNA sequencing method. Two cases of extragenital Bowen's disease were positive for types 16 and 33 of mucosal HPV, respectively. None of the squamous cell carcinoma cases were positive. Neither patients with digital Bowen's disease (n = 5) nor those with squamous cell carcinoma (n = 3) showed any mucosal high-risk HPV. Mucosal high-risk HPV DNA was confirmed in 5 (55.6%) of the 9 patients with bowenoid papulosis. HPV 16 was most prevalent (n = 3), while the DNA of HPVs 35 and 67 was detected in one sample for each of the two types. Our study demonstrated that two (6.7%) of the patients with 30 extragenital Bowen's disease were positive for types 16 and 33 of mucosal HPV, respectively. HPVs belonging to the mucosal high-risk group may participate in the development of extragenital Bowen's disease. However, we could not find any relationship between the mucosal high-risk HPV and Bowen's disease or squamous cell carcinoma in the fingers.

Bowen disease of the palm associated with human papillomavirus 52

Human papillomavirus (HPV) is a well-known risk factor for many human cancers, especially cervical cancers. Among the nonmelanoma skin cancers, Bowen disease (BD) of the genitalia and fingers has also been shown to be closely associated with the high-risk types of HPV, especially HPV16. We report a case of BD of the palm, which is a very rare location for BD. In addition to its rare location, HPV52, which is classified as a mucous high-risk HPV type, was detected in the lesion by PCR restriction fragment length polymorphism analysis. To our knowledge, this is the first reported case of BD associated with HPV52.

Progeny of Lgr5-expressing hair follicle stem cell contributes to papillomavirus-induced tumor development in epidermis

Epidermal keratinocytes and hair follicle (HF) stem cells (SCs) expressing oncogenes are competent at developing squamous cell carcinomas (SCCs) in epidermis and HFs, respectively. To determine whether bulge and hair germ (HG) SCs from HF contribute to SCC generation at distant epidermis, the most frequent epidermal region where these lesions arise in human skin, we used a skin cancer mouse model expressing E6 and E7 oncoproteins from Human papillomavirus (HPV) 16 in SCs and basal keratinocytes. This previously described mouse model recapitulates the human skin papillomavirus-induced SCC pathology. We show that E6 and E7 expression promote the expansion of keratin 15 (K15)-expressing cells. These K15(+) aberrant cells exhibit some HGSC markers and diminished expression of Tcf3 and Sox9 hair SC specification genes, which are accumulated in HFs and mislocalized to interfollicular epidermis. Leucine-rich G-protein-coupled receptor 5 (Lgr5)-expressing SCs, localized in the bulge and HG, are the origin of the expanded K15(+) cell population. A large subset of the Lgr5(+) SC progeny, expressing K15 and P-cadherin, is aberrantly mobilized to the upper region of HFs and the epidermis, and accumulates at E6/E7-induced pre-neoplastic lesions and epidermal tumors. These findings indicate that aberrant accumulation of altered SCs in HFs and their subsequent migration to the epidermis contribute to HPV-induced tumor development.

Verrucous carcinoma of the nail unit

Verrucous carcinoma (VC) of the nail bed and matrix is a rare malignancy that is often misdiagnosed as a benign condition. We present a case of a 65-year-old woman with a 2-year history of a progressive right fourth fingernail verrucous plaque replacing and surrounding her entire fourth fingernail. Diagnosis of VC was confirmed by a longitudinal biopsy and patient underwent en bloc excision and skin graft placement. The patient remained disease free with acceptable function of the digit at 24 months of follow-up. Although uncommon, VC must be considered in all patients with a persistent and enlarging verrucous lesion involving the nail apparatus. Preoperative evaluation must include an adequate biopsy specimen to avoid misdiagnosis of verruca vulgaris. Digital radiographs are recommended to evaluate local invasion to bone.