Endocrine Abstracts

Introduction: Pituicytoma is a rare neoplasm of the sellar region, believed to originate from neurohypophyseal cells. Tumor resection is the primary treatment option, but may remain incomplete due to excessive bleeding of the well vascluarized tumor stroma. Therefore the search for alternative or additional treatment regimens is necessary. In a previous publication in 2012 the presence of VEGF-R was shown in one tumor sample, potentially opening the door for modern treatment options. However no series of pituicytomas was analyzed so far.

Material and methods: We analyzed pituicytoma samples collected from three institutions between 2006 and 2015. The tumor tissues were stained for VEGF, VEGFR, TTF1, SSTR 2, SSTR 3, SSTR 5; furthermore the Ki67 fraction was determined. The strength of the stainings were classified from 0=no staining to +++=strong staining. A complementary retrospective analysis of the patient charts regarding sex, age, and primary symptoms, pituitary function, and peri- or postoperative complications was performed.

Results: Ten samples were analyzed; mean patient age was 57.8 years +-16.3 years. Seven samples were acquired from male patients (one relapse) and three from female. All tumors stained strongly positive (+++) for VEGF-R. VEGF was unavailable in six samples, did not stain in 3 and was slightly positive (+) in one sample. Six samples stained positive for TTF1. As for somatostatin receptors, three samples were slightly positive for SSTR2; seven were negative. SSTR3 was + in 1, 3 were ++, 3 were +++ and 3 were 0. SSTR 5 stained +++ in 1, ++ in 5, + in 1 and 0 in three patients. Ki67 was unavailable for seven samples; it was 5% for two samples and 10% in one.

Conclusion: All pituicytomas stained strongly positive for the VEGF receptor presence thus indicating a possible treatment option through targeted therapies in cases where resection remains insufficient. Further research is necessary as to whether tumor growth can be inhibited using this pathway.