An unusual case of pilonidal p16 positive squamous cell carcinoma-a case report

Area of Science:

• Oncology
• Dermatology
• Virology

Background:

• Basaloid squamous cell carcinoma (BSCC) is a rare, aggressive cancer subtype.
• It is frequently associated with p16-expression and high-risk human papillomavirus (HPV), particularly in oropharyngeal and anogenital sites.
• P16-expression serves as a surrogate marker for oncogenic HPV16.

Observation:

• A case of primary cutaneous p16-positive BSCC is presented in an elderly woman.
• The patient had a history of chronic inverse psoriasis in the natal cleft.
• This represents a rare instance of malignant transformation in pilonidal disease, especially in an elderly demographic.

Findings:

• This case is the first documentation of primary cutaneous p16-positive BSCC.
• The patient's extensive cutaneous disease and p16-positivity led to treatment with radiotherapy.
• Radiotherapy was an effective primary treatment modality for this patient's condition.

Implications:

• Highlights the importance of considering p16-expression testing in primary cutaneous BSCC, similar to its use in other sites.
• Suggests radiotherapy as a viable treatment option for extensive or p16-positive primary cutaneous BSCC.
• Expands understanding of BSCC's occurrence in atypical demographics and its association with chronic inflammatory skin conditions.