Top 10 Nested Pattern Head and Neck Lesions to Notice

Area of Science:

• Pathology
• Oncology
• Head and Neck Surgery

Background:

• The "nested" pattern, defined as cellular clusters with intervening stroma lacking lumens, is observed in diverse head and neck lesions.
• This pattern necessitates a broad differential diagnosis encompassing neoplastic and non-neoplastic entities.
• Lesions are categorized by differentiation: neuroendocrine, squamous, thyroid follicular cell, and others.

Purpose of the Study:

• To provide a comprehensive guide for diagnosing "nested" lesions in the head and neck.
• To systematically review entities exhibiting a nested growth pattern.

Main Methods:

• Literature review of head and neck lesions with a nested appearance.
• Analysis of morphologic, immunohistochemical, clinical, and radiographic features.

Main Results:

• Numerous entities demonstrate a nested pattern, including neuroendocrine neoplasms, paraganglioma, middle ear neuroendocrine tumors, medullary and poorly differentiated thyroid carcinomas, olfactory neuroblastoma, ectopic pituitary neuroendocrine tumors, hyalinizing trabecular tumors, solid papillary thyroid carcinoma, solid cell nests/C-cell hyperplasia, necrotizing sialometaplasia, and meningioma.
• Morphologic and immunohistochemical characteristics are crucial for differentiating these entities.

Conclusions:

• A systematic approach integrating morphologic and immunohistochemical findings is essential for accurate diagnosis of nested head and neck lesions.
• This review aids pathologists and clinicians in navigating the differential diagnosis of these challenging entities.