Non-melanoma skin cancers (NMSC) are increasing in number because of the larger elderly population. NMSCs are less likely to metastasise than melanomas.

Basal Cell Carcinoma (‘Rodent Ulcer’)

Basal cell carcinoma (BCC) is also known as a ‘rodent ulcer’ as the surface can be damaged and ulcerated. BCC is the most common skin and human malignancy and occurs on sun exposed areas of the head and neck in the elderly. With increasing sun exposure BCCs now affect younger adults in their thirties and forties. BCCs grow very slowly but can be locally invasive.

Nodulocystic BCC is the most common type. It usually develops on the face as a pearly skin-coloured cystic papule or nodule with telangiectasia and a rolled edge. It can ulcerate and there may be a history of bleeding or crusting (Figures 34.1 and 34.2). The lesion can be pigmented causing confusion with a melanoma.

Superficial BCC is the second most common type, usually appearing on the trunk as scaly pink to red–brown patches or papules and can have a pearly border (Figure 34.3). The differential diagnoses include Bowen’s disease and inflammatory conditions such as psoriasis and eczema.

Morphoeic (sclerosing) BCC appears as a scar-like, waxy plaque or papule (Figure 34.4). The edges are not well defined, with tumour extension beyond the observed clinical margins. These usually occur on the face and can have ulceration, bleeding and crusting.

Histology

The histology shows neoplastic basaloid cells occurring in nests that are organised as islands of tumour cells more dense at the periphery (palisading) with a dermal inflammatory infiltrate (Figure 34.5).

Diagnosis

Clinical diagnosis is sufficient for most BCCs; however, if there is clinical doubt a biopsy is required. Superficial shave biopsy is the best diagnostic procedure for this epidermal lesion as punch biopsies risk introducing the tumour deeper into the dermis.