Clinical Diagnosis of Basal Cell Carcinoma Subtype

Skin cancer is the most common cancer in Caucasians. Basal cell carcinoma (BCC) is the most frequent skin cancer with around 44.000 new tumours per year in the Netherlands, and its incidence is still rising. Prior to treatment, a punch biopsy (PB) is taken from the suspected lesion, in order to determine the subtype of BCC. There are three different histological subtypes of BCC, from least to most aggressive: superficial, nodular and aggressive. Based on the most aggressive subtype seen in the PB, a suitable surgical margin is chosen. Surgical excision (SE) is the treatment of first choice in all BCC subtypes according to the Dutch guidelines. Recent developments of non-invasive therapies for superficial BCC might be the first choice of treatment in the future. These non-invasive treatments (photodynamic therapy (PDT), Imiquimod and 5-fluorouracil (5-FU)) have better cosmetic results than SE and are therefore also used in the Maastricht University Medical Center. Drawback is a higher recurrence rate than SE. As nodular and aggressive subtypes grow deeper into the dermis, they have to be treated with SE with a 3 mm and 5 mm margin respectively. If BCC are located in the H-zone, the treatment will be Mohs micrographic surgery (MMS). Unfortunately, 30% of subtypes seen in the PB do not correspond with the subtype seen in the subsequent SE/MMS. The consequence is overtreatment and undertreatment. A potential better or equal way to determine the BCC subtype might be the clinical diagnosis. To our knowledge, there is no literature about the diagnostic value of the clinical diagnosis to determine the subtype of BCC seen in the SE/MMS specimen. We want to confirm the hypothesis that the clinical diagnosis is as good as, or even better than the histological diagnosis by PB to determine the BCC subtype in the subsequent SE/MMS. In this case, patients don't have to undergo an extra procedure, diagnostic route is shortened. \- Primary objective: to establish the observed agreement of clinical diagnosis compared to histological diagnosis by to determine the most aggressive subtype of BCC \- Secondary objectives: inter-observer and intra-observer variability of dermatologists and pathologists to determine subtype BCC.

Sex

All

Minimum age

18 Years

Inclusion Criteria:

* All patients aged 18 years or older, otherwise healthy, with ≤ three primary (no previous treatment) clinically determined BCC will be recruited for this study.

Exclusion Criteria:

* Patients using immunosuppressive drugs. Genetic skin cancer disorders. Earlier treatments at the same site. Age under 18 years. More than 3 clinical suspected BCCs. Not capable of informed consent.