[735] Estrogen and Progesterone Receptor Positive Stroma in Pediatric Cystic Renal Dysplasia: An Immunohistochemical Study of 18 Cases

J Coviello-Malle, JK McKenney, A Heerema-McKenney. UAMS, Little Rock, AR; Stanford, Stanford, CA

Background: Estrogen receptor (ER) and progesterone receptor (PR) positive stroma is found in a variety of renal neoplasms including cystic nephroma, mixed epithelial-stromal tumor (MEST), and angiomyolipoma with epithelial cysts. A recent study has reported ER and PR positive stroma in non-neoplastic renal parenchyma and suggested that it represents a metaplastic response related to obstruction (Tickoo S. et al. Mod Pathol 2008;21:60-65). We studied a series of pediatric multicystic renal dysplasia, a non-neoplastic lesion with characteristic spindled stroma surrounding abnormal tubules, to assess expression of ER, PR, CD10, calretinin, and inhibin.
Design: Cases of cystic renal dysplasia were identified from surgical and autopsy archives. Patient age, sex, kidney laterality, and pre-operative diagnoses were recorded. H&E sections were reviewed to confirm the diagnoses. Immunohistochemical stains for ER, PR, CD10, calretinin and inhibin were performed and scored as percent nuclear reactivity (ER and PR) or qualitatively (0-3+) in the spindled stroma.
Results: 15 surgical and 3 autopsy cases were identified (n=18). Ages ranged from 3 days to 13 years (mean: 3 years) and the male:female ratio was 14:4. Only two cases (both autopsy) had bilateral disease. Evidence of urinary obstruction (pelviectasis or megaloureter) was present in 5 (28%) cases. At least focal ER expression was seen in 15/18 cases (83%) including all four females, and 11 males. ER staining ranged from <10% to 70% of spindled cells. PR staining was seen in only three (17%) cases (2 female, 1 male) and all were focal (<10%). Only the three autopsy cases of very young or premature neonates had no ER expression. CD10 expression was seen in 12/18 cases (67%), but no correlation with ER expression was found. Not all cases with obstruction expressed ER, and strong ER reactivity was detected in cases without hydronephrosis. Immunostains for calretinin and inhibin were negative in all cases, consistent with the absence of luteinized stroma.
Conclusions: These findings support that a subset of non-neoplastic renal stromal proliferations express ER and PR. As recently proposed, incidental non-neoplastic stromal proliferations in adults may represent a metaplastic response to obstruction or injury, similar to obstructive or segmental dysplasia in childhood.
Category: Genitourinary (including renal tumors)

Monday, March 9, 2009 9:30 AM

Poster Session I Stowell-Orbison/Autopsy Award # 116, Monday Morning