Endocrine diffuse system--histological and functional aspects interrelated with the tumoral pathology

Area of Science:

• Endocrinology
• Cell Biology
• Neuroscience

Background:

• Historically, endocrine cells were thought to originate exclusively from neural crests.
• Recent discoveries reveal over 40 distinct endocrine cell types with varied developmental origins.
• Only a small subset, approximately 6-7 types, are confirmed to derive from neural crests.

Purpose of the Study:

• To elucidate the diverse origins of endocrine cells within the diffuse neuroendocrine system (DNES).
• To highlight the distinct characteristics and identification methods for various endocrine cell types.
• To address the diagnostic challenges in differentiating benign and malignant endocrine cell proliferations.

Main Methods:

• Fluorescence microscopy was used to differentiate serotonin- (yellow) and catecholamine- (green) secreting cells using formaldehyde.
• Silver salt impregnation is the standard technique for staining diffuse endocrine system cells.
• Electron microscopy was employed to examine dense granules within endocrine cells, noting alterations in malignancies.

Main Results:

• The study confirms that endocrine cells have multiple origins, challenging the sole neural crest derivation theory.
• Specific fluorescence properties (yellow for serotonin, green for catecholamines) aid in cell identification.
• Electron microscopy reveals characteristic dense granules, which are altered in malignant endocrine cell tumors.
• Many hormones secreted in the intestine are also found in the central nervous system.

Conclusions:

• The diffuse neuroendocrine system is more complex than previously assumed, with diverse cell origins.
• Standard histological and ultrastructural methods aid in characterizing these cells and their pathologies.
• The distinction between benign and malignant endocrine cell proliferations requires further clarification due to overlapping features.