# A Case of a Longstanding Perianal Lesion Presenting as Advanced Squamous Cell Carcinoma of the Anus

## TL;DR

A man with a long-term untreated perianal lesion developed advanced anal cancer, highlighting the importance of early diagnosis and treatment.

## Contribution

This case highlights the clinical implications of delayed diagnosis and p16-negative tumor biology in anal squamous cell carcinoma.

## Key findings

- Delayed care led to advanced T3N1a SCCA in a patient with psychiatric and nicotine comorbidities.
- HPV-negative and p16-negative tumor biology correlates with poor prognosis in this case.
- Multidisciplinary care and smoking cessation are emphasized for improved outcomes in SCCA.

## Abstract

Squamous cell carcinoma of the anus (SCCA) is a rare malignancy with rising incidence. Early-stage disease has a favorable prognosis, but advanced tumors, nodal involvement, and p16-negative status worsen outcomes. We present a 63-year-old man with psychiatric comorbidities and long-term nicotine dependence who delayed care for a four-year ulcerated perianal lesion. Imaging revealed a large invasive anal mass and bilateral inguinal lymphadenopathy (T3N1a). Biopsy confirmed poorly differentiated, HPV-negative, p16-negative SCCA. He began chemoradiotherapy with supportive care. This case underscores the impact of delayed diagnosis and tumor biology on prognosis, highlighting the need for early recognition, multidisciplinary care, and smoking cessation.