Lymph Node Fine-Needle Aspiration: 2 Cases Demonstrating Benefits of Ultrasound Guidance
Pathologist performed fine-needle aspiration (FNA) biopsies yield high adequacy rates, result in effective triage of material for additional studies, and offer a minimally invasive method for tissue procurement. Ultrasound-guided FNA (US-FNA) expands the scope of pathologists' FNA capabilities allowing for deeper, nonpalpable lesions to be biopsied while avoiding crucial structures and enabling targeted biopsies of sonographically concerning regions. To illustrate the utility of US-FNA in clinical practice, we present 2 cases in which diagnostic material was obtained by pathologist-performed US-FNA from neck lymph nodes detected on positron emission tomography scans. The first was a 71-year-old woman with a history of both invasive lung and breast adenocarcinomas, and the second was a 60-year-old woman with a history of lower gastrointestinal tract squamous cell carcinoma. The lymph node biopsy from the first patient yielded adequate material to perform molecular diagnostic studies, detecting an activating KRAS mutation, providing additional prognostic and therapy guiding information. In the second case, ultrasound guidance allowed the pathologist to perform a biopsy on a nonpalpable lymph node and obtain a diagnosis from this minimally invasive procedure. Both lymph nodes featured characteristics indicative of involvement by metastatic carcinoma. Ultrasound examination can help characterize lesions, guiding cytopathologists to select an appropriate biopsy trajectory for optimal sampling.
