Diagnosis of skin cancers
Any skin lesion that is progressively enlarging should be assessed and examined by a trained doctor. Contrary to popular belief, malignant skin tumours do not always cause pain, so this symptom is not reliable. If a skin cancer is suspected, your doctor may advise and order a biopsy under local anaesthetic for microscopic examination. Upon confirmation of a malignant skin tumour, the doctor can assess and advise the best option for treatment.
The most common form of treatment of a malignant skin tumour is surgery. There are 2 surgical options: standard wide excision and Mohs micrographic surgery (MMS). MMS involves surgically removing skin cancer layer by layer like peeling an onion, mapping the excised specimen and examining the entire margins of each layer under the microscope. This facilitates the complete tracing of the tumour roots until healthy, tumour-free tissue is reached.
MMS thus ensures the highest possible success rate. In fact, reported 5 year cure rates for primary skin tumours treated by MMS is 99% versus 93% for standard excision. Standard surgical excisions involve excising the tumours with a predetermined margin and assessing the excised specimens in the pathology laboratory either with a “breadloaf” or “quandrant” method. These methods leave marginal areas between the sections not microscopically visualised. In fact, it has been shown the above techniques only evaluate about 1% of total margins. The failure to detect subclinical microscopic tumour foci may result in tumour recurrence in spite of “clear” margins on histology report.
Furthermore, as the tumour roots are being traced and only tumour involved tissues are removed, the technique is also considered to be tissue sparing and is of great value in the excision of tumours occurring in cosmetic sensitive areas like the “H-zone” of the face (around the eyes, mouth and, nose) and the ear, to maximize cosmetic and functional outcome post surgery.
In addition, as there is greater confidence of clearance of the tumour, the resultant defect can be better managed. Surrounding skin can be mobilized to facilitate closure and hiding the scars at cosmetic subunits junctions, thus achieving better cosmetic outcome.
In certain situations whereby complete excision may not be feasible, other forms of therapy such as radiotherapy, photodynamic therapy or topical therapy may be used.