Final answer:
Sentinel lymph node biopsy (SLN) conditions are related to the characteristics of cancerous lesions, including asymmetry, irregular borders, varied color, diameter larger than 6 mm, and evolving changes in the lesion. SLN is often considered when these criteria are present, alongside a patient's medical history of skin cancer, precancerous lesions, or immune system compromisation.
Step-by-step explanation:
Conditions for sentinel lymph node biopsy (SLN) are related to cancer staging and characteristics that suggest the cancer might have spread. SLN is a procedure used to determine if cancer, such as melanoma or squamous cell carcinoma, has spread to the lymph nodes. For melanoma, the measuring criteria include:
- Asymmetry - meaning the two sides of the mole or lesion are not symmetrical.
- Borders - where the edges are irregular in shape.
- Color - characterized by varied shades, often of brown or black.
- Diameter - specifically, if it is larger than 6 mm (0.24 inches).
- Evolving - any changes in the shape, size, or color of the lesion.
Other criteria consider the patient's history, such as pre-existing conditions like precancerous skin lesions, family or personal history of skin cancer, an immune system compromised by other conditions, or exposure to radiation or carcinogens like arsenic.
Regarding the specific conditions mentioned in the question:
- Smoking is a risk factor for many cancers but not a condition for SLN itself.
- Lesion size greater than 3 cm might be considered for SLN, although 6 mm is a specific threshold for melanoma.
- Calcification and spiculation are characteristics sometimes seen in malignancies and may suggest a higher likelihood of cancer spread, possibly making SLN more warranted.