Polydactylous subungual squamous cell carcinoma caused by chemical contact

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.

Squamous Cell Carcinoma of the Nail Unit: A Clinical Histopathologic Study and a Proposal for Classification

BACKGROUND

There is no consensus on the classification, grading, and the treatment of nail squamous cell carcinoma (NSCC).

OBJECTIVE

The aim of the study was to propose a possible classification of NSCC.

MATERIALS AND METHODS

Nail squamous cell carcinoma referred from January 2006 till December 2014 was included. On the basis of the clinical presentation, patients with NSCC were divided in 2 groups. Group A tumors presented as nodular or ulcerated masses of the nail bed, whereas Group B tumors presented as hyperkeratotic bands. In these 2 groups, differences in proportions (sex, histopathologic grading, and treatment performed) were evaluated with the chi-square test.

RESULTS

Forty-one NSCCs were included. The groups of NSCC differed regarding: (1) the age of the patients, (2) histopathology, and (3) surgical approach.

CONCLUSION

Nail squamous cell carcinomas may originate from 2 different epithelia, presenting a diverse clinical behavior. The correct identification and diagnosis of each subgroup of NSCC could be helpful in standardizing management of this tumor. Future studies considering human papillomavirus subtyping and including a major number of tumors should be performed to confirm or reject the authors' hypothesis.

LIMITATIONS

This is a retrospective study, presenting the data and the experience of a single institute.

Squamous Cell Carcinoma of the Nail Unit: Review of the Literature

Squamous cell carcinoma of the nail unit (SCCNU) is often misdiagnosed and improperly treated because it mimics a number of other conditions. This review details current knowledge of anatomy, pathophysiology, clinical presentation, diagnosis, and treatment of SCCNU. A heightened clinical awareness is critical to treating SCCNU and preventing development of advanced disease at which time amputation is needed and metastasis may occur. Physicians should consider SCCNU in each case of a nail abnormality unresponsive to topical treatment. For adequate diagnosis and excision of SCCNU, timely and appropriate specialist referral is necessary.