Evaluation of progesterone and estrogen receptor expression in 15 meningiomas of dogs and cats.
OBJECTIVE
To evaluate progesterone and estrogen receptor expression in meningiomas of the CNS in dogs and cats.


METHODS
8 dogs (1 of which was treated with gestrinone) and 5 cats with intracranial meningiomas and 2 dogs with spinal cord meningiomas; tissue samples were also obtained from 1 clinically normal dog and 1 clinically normal cat.


METHODS
Meningioma tissue was obtained during surgery or at necropsy; samples were processed for histologic classification and immunohistochemical evaluation of the proportion of tumor cells with progesterone and estrogen receptors. Correlation among receptor expression, tumor grade, and histologic subtypes was determined.


RESULTS
Several histologic subtypes of intracranial meningiomas were detected among tissue samples. In the cats, all intracranial meningiomas were benign. Progesterone receptor immunoreactivity was detected in 14 of 15 meningiomas. Progesterone receptor expression was identified in > 80% of cells in 8 intracranial meningiomas (4 dogs and 4 cats) and 2 spinal cord meningiomas. In samples of malignant transitional and granular cell meningiomas in dogs, progesterone receptors were detected in 32 and 4.8% of cells respectively. In 1 cat, 38% of tumor cells had progesterone receptors. In a dog treated with gestrinone, no progesterone receptors were detected in the intracranial meningioma. Estrogen receptors were only detected in the tumor of 1 dog.


CONCLUSIONS
Results indicate a high proportion of progesterone receptors in cells of meningiomas of the CNS in dogs and cats. Antiprogesterone treatment may have a role in the treatment of unresectable or recurrent meningiomas in dogs and cats.
Adamo
P Filippo
PF
Department of Medical Sciences, School of Veterinary Medicine, University of Wisconsin, Madison, WI 53706, USA.
Cantile
Carlo
C
Steinberg
Howard
H
D000818:Animals; D002371:Cat Diseases / Q000473:pathology*; D002415:Cats; D004283:Dog Diseases / Q000473:pathology*; D004285:Dogs; D008577:Meningeal Neoplasms / Q000473:pathology / Q000662:veterinary*; D008579:Meningioma / Q000473:pathology / Q000662:veterinary*; D015877:Miosis; D009336:Necrosis; D009361:Neoplasm Invasiveness; D011960:Receptors, Estrogen / Q000378:metabolism*; D011980:Receptors, Progesterone / Q000378:metabolism*; D013120:Spinal Cord Neoplasms / Q000473:pathology / Q000662:veterinary*
D011960:Receptors, Estrogen; D011980:Receptors, Progesterone