Diagnosing diseases and conditions may require a various array of diagnostic tests and modalities. This column discusses when a test or procedure is indicated as well as its advantages, disadvantages, economic impact, and reliability of results.
Melanomas are typically pigmented tumors of the skin and mucous membranes. Some melanoma tumors may be nonpigmented (amelanotic).
Early studies found that the World Health Organization (WHO) staging system for melanoma (see Box) provided prognostic information,1 but more recent information suggests that these criteria should be combined with information from histopathology (especially the mitotic index).
Current recommendations for staging melanoma include:
- Detailed information on the location of the primary tumor
- Accurate tumor measurements and lymph node evaluation by cytology or biopsy
- Careful evaluation for metastasis by thoracic radiography, CT, or MRI
- Evaluation of the histopathology criteria listed above.
While such information will not provide an accurate prognosis for every canine patient with melanoma, it will allow the owner and oncologist to make a more individual treatment decision.