Pain, mast cells, and nerves in peritoneal, ovarian, and deep infiltrating endometriosis.
OBJECTIVE
To detect and quantify mast cells in peritoneal, ovarian, and deep infiltrating endometriosis and to study the relationship between mast cells and nerves in endometriosis.


METHODS
Prospective histological and immunohistochemical study.


METHODS
University of Brussels, Belgium.


METHODS
Sixty-nine women undergoing laparoscopic excision of endometriosis for pain. Thirty-seven biopsies of normal tissue were obtained from women without endometriosis.


METHODS
Excision of endometriosis from different anatomical locations.


METHODS
Immunohistochemistry with chymase and tryptase to confirm the presence of mast cells and activated mast cells, respectively, in endometriotic lesions. Quantification of mast cells, activated mast cells, and degranulating mast cells in the different locations of endometriosis. Study of the relationship between mast cells and nerves by quantifying mast cells located less than 25 mum from nerves immunohistochemically stained with S-100 protein. Preoperative pain score evaluation by visual analogue scales.


RESULTS
Patients with deeply infiltrating lesions had significantly higher preoperative pain scores than patients with peritoneal or ovarian endometriosis. Mast cells and degranulating mast cells are significantly more abundant in endometriotic lesions than in nonaffected tissues. Deep infiltrating lesions show a significantly higher number of mast cells, activated mast cells, and mast cells located <25 microm from nerves than peritoneal and ovarian lesions. We found significantly more degranulating mast cells in deep infiltrating lesions than in peritoneal lesions.


CONCLUSIONS
The presence of increased activated and degranulating mast cells in deeply infiltrating endometriosis, which are the most painful lesions, and the close histological relationship between mast cells and nerves strongly suggest that mast cells could contribute to the development of pain and hyperalgesia in endometriosis, possibly by a direct effect on nerve structures.
Anaf
Vincent
V
Department of Gynaecology, Academic Hospital Erasme, Free University of Brussels, Brussels, Belgium. vincent.anaf@ulb.ac.be
Chapron
Charles
C
El Nakadi
Issam
I
De Moor
Veronique
V
Simonart
Thierry
T
Noël
Jean-Christophe
JC
D000328:Adult; D004715:Endometriosis / Q000150:complications / Q000473:pathology*; D005260:Female; D006801:Humans; D006930:Hyperalgesia / Q000209:etiology / Q000473:pathology*; D008407:Mast Cells / Q000473:pathology*; D010049:Ovarian Diseases / Q000150:complications / Q000209:etiology*; D010053:Ovary / Q000294:innervation / Q000473:pathology; D010532:Peritoneal Diseases / Q000150:complications / Q000473:pathology*; D010537:Peritoneum / Q000294:innervation / Q000473:pathology