Mast cells in cluster headache. Ultrastructure, release pattern and possible pathogenetic significance.

Cluster headache remains a disease with almost totally unknown etiology and poorly understood pathogenesis. Some evidence has been presented to suggest that histamine released from mast cells might possibly be responsible for the initiation of pain attack. The authors present ultrastructural data concerning cutaneous mast cells in the painful region in patients suffering from cluster headache. The biopsies were taken between attacks in a bout. The fine structure of the mast cells (namely swollen granules, zones of decreased density, membrane-bound vesicles and granular fusion) are consistent with the dissolution pattern of secretion. The possible role of antidromic-reflex activation of the mast cells is also discussed.