Perils of diagnosis and detection of subungual squamous cell carcinoma

First Dorsal Metacarpal Artery Flap for Thumb Reconstruction Postresection of Subungual Squamous Cell Carcinoma

Subungual squamous cell carcinoma refers to rare tumors that arise from the digits, most commonly in the thumb and big toe. These tumors are frequently diagnosed late due to them presenting as chronic wounds or wart infections. They are low-grade tumors that rarely have nodal involvement, and their treatment options include surgical resection with or without amputation, and radiotherapy for patients who cannot tolerate surgery. We present a case of a patient who underwent tumor excision and immediate reconstruction of the digit.

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: 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.

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.

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.

Subungual squamous cell carcinoma

Subungual squamous cell carcinoma (SCC) is rare. We present a case of subungual SCC with invasion into the underlying bone and review the literature.