This study examines tumor- en surgical characteristics of stage T3 cutaneous squamous cell carcinomas on the scalp, diagnosed between 2010 and 2018. Histological data and patient- and tumor characteristics were collected.

Cutaneous squamous cell carcinoma is the second most common type of non-melanoma skin cancer, following basal cell carcinoma. Following the American Joint Committee on Cancer Tumour, Node and Metastasis (TNM) Classification of Malignant Tumors staging system (TNM8), T3 cutaneous squamous cell carcinomas comprise an interesting group, especially on the scalp, because of the thin subcutaneous fat layer. According to the TNM8 criteria, T3 include all cutaneous squamous cel carcinomas with greatest tumor dimension ≥4cm, tumors with minimal bone erosion or perineural growth (defined as involvement of the nerve sheath of a nerve lying deeper than the dermis or measuring 0.1mm or larger in caliber or showing clinical or radiographic involvement of nerves without invasion of the skull base) or with deep invasion. Deep invasion is defined as invasion deeper than the subcutaneous fat or a tumor thickness >6mm. The scalp has a natural anatomical and oncological barrier for extension in depth known as the epicranial aponeurosis, also called the galea aponeurotica.

This retrospective study, examines the tumor- en surgical characteristics of these stage T3 cutaneous squamous cell carcinomas on the scalp.

Inclusion Criteria:

• stage T3 cutaneous squamous cell carcinoma of the scalp (histologically proven)
• surgical treatment or radiotherapy treatment

Exclusion Criteria:

• metastasis by diagnosis
• stage T1/T2/T4

Data from patients are collected retrospectively using data from the Pathological Anatomical National Automated Archive (PALGA) of the MUMC+ between 2010 - 2018. The TNM staging of all cutaneous squamous cell carcinomas in the research period was reassessed and classified following the TNM 8 criteria.