The clinical suspicion can be readily confirmed by a punch biopsy.
The first thing to do is a full history and clinical examination. In
particular I would enquire about a past history of any cancers, the family
history, occupation (indoors or outdoors, working with carcinogens), history of
sunburn and smoking history. On examination, I would carefully look for
evidence of metastatic disease in particular in the adjacent lymph node basins,
the side of the neck and the supraclavicular fossa. I would carefully inspect
the skin all over the head and neck because these lesions are often multiple.
There is no blood test that would be of any particular interest.
Detailed scanning should be avoided until the suspected diagnosis is
confirmed. A CXR may be worth while however.
The diagnosis is most readily confirmed by a punch biopsy which may be
easily accomplished under local anaesthetic. An excisional biopsy could be
considered if the lesion was smaller but in this case excision would not be
feasible without embarking on elaborate reconstruction so it would be best to
establish the malignant diagnosis prior to a major excision and
reconstruction.
Skin scrapings (and nail clippings) are usually performed to check for fungal
infection.
An positron emission tomogram (PET) scan may be useful to stage various
malignancies but is not good to establish the diagnosis. The most important
modality to confirm the nature of an abnormality is tissue diagnosis which
depends on tissue.
Woods light is ultraviolet light and is useful in establishing the diagnosis of XXX
