Dermatologic Surgery and Cutaneous Oncology

Imaging Use in Squamous Cell Carcinoma of the Nail Apparatus

Squamous cell carcinoma (SCC) is the most common nail unit malignancy, and bony invasion may occur at this site. Mohs micrographic surgery (MMS) or surgical excision is the standard of care. Amputation is considered when bony involvement cannot be addressed with digit sparing surgery.

Imaging findings changed management in 17.6% of patients undergoing preoperative imaging and in 10.9% of all patients. A change in treatment was defined as amputation rather than local excision or MMS.

No clinical or histologic factors in a 20-year retrospective study reliably predicted the risk for underlying bony invasion or correlated with bony abnormalities on imaging. While imaging may play a role in select cases, the majority of nail unit SCC cases can be successfully managed without imaging.

Demographic and Tumor Comparison by Imaging Status (N = 55)

1997 – 2017

A multicenter, follow-up study will further identify variables predictive of bony invasion on imaging to guide clinical decision making. 

The most commonly used imaging modalities and observed imaging findings are summarized below. In 6 patients (17.6%), imaging findings directly impacted patient care and showed findings of bony infiltration.

Imaging Characteristics Among Patients (N = 34)

1997 – 2017

SCC Treatment Modality by Imaging Status (N = 55)

1997 – 2017

No significant differences in treatment were identified when comparing groups with and without imaging.