Delphian (prelaryngeal/precricoid) lymph node

• Small lymph node located directly anterior to the cricothyroid membrane, between the cricothyroid muscles
• Node positioned above the thyroid isthmus in the midline prelaryngeal region (Level VI)
• Enlarged node in patient with laryngeal cancer or thyroid malignancy warrants urgent reporting

• The Delphian node is located in the central compartment (Level VI) between the bilateral cricothyroid muscles, directly anterior to the cricothyroid membrane and above the thyroid isthmus.
• On cross-sectional imaging (CT or MRI), it appears as a small rounded or oval lymph node in the midline prelaryngeal space, anterior to the laryngeal framework.
• Normal Delphian nodes are typically less than 5 mm in short-axis diameter; any node larger than 5-10 mm in this location should be considered suspicious for metastatic disease.
• The node receives lymphatic drainage primarily from the upper poles of the thyroid gland and the larynx, particularly the anterior commissure, making it a sentinel node for laryngeal malignancy.
• On imaging, careful attention to the prelaryngeal space is needed because the Delphian node is small and easily overlooked on routine imaging protocols.
• Enhancement characteristics on contrast-enhanced CT or MRI mirror those of other metastatic cervical nodes; suspicious nodes may show heterogeneous or marked enhancement.
• The Delphian node is distinct from the central compartment nodes (Level VI) that include pretracheal and paratracheal nodes, though all are in the central compartment.
• Clinical significance: involvement of the Delphian node indicates either direct spread from laryngeal cancer or part of diffuse nodal involvement in head and neck squamous cell carcinoma, signifying advanced disease and poor prognosis.

• Thyroglossal duct cyst: located more superiorly in the midline, follows midline raphe from foramen cecum to thyroid, and has different imaging characteristics (fluid signal on MRI, no enhancement unless infected).
• Pretracheal lymph node (Level VI): located inferior to the Delphian node, between trachea and thyroid; distinguished by more inferior location below the thyroid isthmus.
• Small laryngeal granuloma or inflammatory lesion: located on laryngeal surface rather than anterior to cricothyroid membrane; associated with vocal cord pathology or prior intubation.
• Prominent cricothyroid muscle or cartilage artifact: differentiated by lack of lymphoid characteristics on imaging and absence of enhancement pattern typical of metastatic lymph nodes.

When reporting Delphian node findings, clearly state the location ("prelaryngeal lymph node anterior to the cricothyroid membrane at Level VI"), describe the short-axis diameter, and note enhancement characteristics; always alert the surgeon to this location because it is not routinely included in radical neck dissections.

• Overlooking the Delphian node due to its small size and midline location; many radiologists fail to specifically evaluate the prelaryngeal space anterior to the cricothyroid membrane.
• Confusing the Delphian node with other Level VI nodes (pretracheal or paratracheal nodes) located at different anatomic levels, leading to inaccurate surgical planning.
• Underestimating significance of a small (5-10 mm) Delphian node in a patient with laryngeal cancer; any enlargement in this location warrants reporting regardless of size compared to other cervical nodes.
• Assuming that absence of obvious enlarged nodes excludes Delphian involvement; subtle enhancement or minimal enlargement in the prelaryngeal space must be documented, especially in patients with anterior laryngeal or thyroid primary tumors.