# Squamous cell carcinoma and Crohn's disease: a sometimes-challenging diagnosis

## TL;DR

Crohn's disease patients may develop squamous cell carcinoma that mimics abscesses, leading to delayed diagnosis and poor outcomes.

## Contribution

Highlights the risk of squamous cell carcinoma in Crohn's disease patients and the importance of early diagnosis.

## Key findings

- Squamous cell carcinoma in Crohn's disease can mimic abscesses, causing diagnostic delays.
- Patients on thiopurines like azathioprine may have increased skin cancer risk.
- Early biopsy and multidisciplinary treatment are crucial for better outcomes.

## Abstract

Aim: Non-melanoma skin cancers are more common in people with inflammatory bowel disease. However, these tumors can rarely mimic a cutaneous manifestation of the disease, which delays diagnosis and clouds prognosis. Observation: A 35-year-old man with stenosing and fistulizing ileocolic Crohn's disease developed squamous cell carcinoma mimicking a groin fold abscess. After surgical drainage of the abscess, despite antibiotics and therapy combining azathioprine with infliximab, the abscess has recurred. Biopsies revealed a cutaneous squamous cell carcinoma. Palliative radiotherapy-chemotherapy was initiated, but the patient died after 3 months. Conclusion: This observation illustrates the increased risk of non-melanoma skin cancers in inflammatory bowel disease patients, particularly those exposed to thiopurines, and the value of diagnosing them at an early stage.

Clinicians should be aware of the risk of skin neoplasia in patients with inflammatory bowel disease (IBD) on long-term azathioprine treatment.

Malignancy should be considered in patients with IBD longstanding peri-anal disease especially in the case of atypical location or appearance.

Where squamous cell carcinoma develops in patients with Crohn's disease, there is often a delay in appropriate medical management due to a low level of clinical suspicion of malignancy.

It is important for clinicians to be cautious when treating immunocompromised patients with skin lesions, and early consideration of biopsy is recommended.

Early diagnosis and timely intervention are essential in the management of squamous cell carcinoma, as a combination of surgical and oncological approaches can potentially lead to a cure.