Which methods can be used for microscopic assessment of cN?

The chosen answer accurately reflects the methods used for microscopic assessment of cN, which refers to clinical nodal status in oncology. Fine Needle Aspiration (FNA), core biopsy, and sentinel node biopsy are procedures specifically designed to obtain tissue samples from lymph nodes. These methods allow for histopathological examination, enabling pathologists to determine the presence of cancer cells.

FNA is minimally invasive, using a thin needle to extract a small sample of tissue, while a core biopsy uses a larger needle to obtain a larger sample, providing more tissue for evaluation. Sentinel node biopsy involves removing a limited number of lymph nodes, which are the first nodes to receive lymphatic drainage from the tumor, and is crucial for staging certain cancers, particularly breast and melanoma.

The other options encompass imaging or treatment methodologies rather than direct microscopic assessments. Imaging techniques such as CT scan, MRI, or ultrasound provide visual insights but do not allow for direct tissue sampling to assess microscopic features. Similarly, surgery and radiotherapy, while integral in managing cancer, do not serve the purpose of microscopic assessment necessary for determining the presence and characteristics of cancer within lymph nodes. Thus, the significance of choice B lies in its direct applicability to the evaluation of lymph nodes through tissue sampling, which is essential