How do you approach patients with polypoid/nodular melanoma for adjuvant therapy when Breslow depth is not available on pathology?

If it is nodular, the depth of invasion (Breslow) starts from the outer edge of the lesion vertically down and perpendicular to the dermis, so most likely if polypoid, it will be at least 3 or 4 mm, thus T3 or T4. If ulcerated, T3b or T4b.

For uncertain cases like this, I would recommend a multidisciplinary discussion with your pathologist first. For melanoma, the actual tumor size is not indicative of its invasiveness/risk of lymph node metastases. Melanoma tumors with a more horizontal growth phase (i.e., superficial spreading melanoma) are generally less risky than melanoma with a more vertical growth phase (i.e., nodular melanoma), in turn of lymph node metastases. Hence it's important to know the Breslow depth as it has strongly prognostic implications. If the Breslow depth is not available after extensive review with the pathologist, you can consider using the older staging system (Clark Level), which looks at how far the melanoma has invaded the different skin layers (...