ACTA ENDOCRINOLOGICA (BUC)

Pituitary adenomas are fully characterized only by immunohistochemistry. The technical limitations, gaps and peculiarities influence the pathology diagnosis. More and more data shows that clinically nonfunctioning pituitary adenomas could synthesize or secrete hormones or their subunits. The tumor pathology is monomorphous or polymorphous, difficult to differentiate from normal adjacent tissue. Light microscopy (LM) qualitative analysis using basic or special stains can differentiate between tumor and normal tissue and allows elimination of artifacts. Electron microscopy (EM) completes the diagnosis in selected cases. Pituitary adenomas immunohistochemistry was done by LM in 120 cases (84 ? clinically nonfunctioning adenomas ? NFA and 36 acromegalics with or without PRL secreting adenomas - ACM) using the avidine-biotin complex method. In 26 cases we determined by EM the immunoreactive cells (17 NFA and 9 ACM) using the immunogold method. We observed high tumor immunoreactivity (mono or plurihormonal) in 43/84 (51%) NFA, 13/36 (36%) ACM respectively. Serum excess hormones and tissue immunoreactivity were significantly concordant for prolactin in NFA cases and for GH, in ACM cases (p<0.05). Mute pituitary adenomas have no clinical expression of hormonal products either they produce biologically inactive components or they synthesize but do not secrete hormones in sufficient amounts to increase serum level and to determine a systemic response. A concordance between LM and EM immunoreactivity was observed only for GH in ACM patients group (p<0.05). The differences could be due to dimensions of the samples or the number of granules inside of the cells (sparsely granulated adenomas are negative or low immunoreactive at the LM level). EM evaluation of NFA identified 2 oncocytomas and 4 null cell adenomas. The complete evaluation of pituitary adenomas includ a qualitative and quantitative analysis at the LM level using special methods, validated at the EM level in order to identify clinically mute immunoreactive cells ? a possible target for specific drugs therapies in the future.

Context. Benefits of vitamin D therapies in chronic kidney disease (CKD) are debated. Objective. To compare the effects of medium-term native (VitD) and active (VDRA) vitamin D on parameters of mineral metabolism and arterial function in non-dialysis CKD. Design. Open-label, active comparator, randomized study. Subjects and Methods. Forty-eight adult patients, vitamin D naïve, CKD stage 3 to 5 with increased parathyroid hormone (iPTH) were randomized to receive either oral cholecalciferol 1000UI/day (n=24) or paricalcitol 1mcg/day (n=24) for 6 months. Median changes at end of study vs. baseline in serum calcidiol, iPTH, total alkaline phosphatase (ALP), and cardio-ankle vascular index (CAVI) were the efficacy parameters. Results. Higher increase in calcidiol (15.5 [95%CI 13.3; 17.2] vs. 0.4 [95%CI −6.1; 3.7]ng/mL, p<0.001) were found in VitD group. Conversely, the decline of iPTH (−35.2 [95%CI −83; 9] vs. 13.3 [95%CI −8.1; 35]pg/mL, p=0.008) and ALP (−34 [95%CI −58; −11] vs. −10 [95%CI −23; −2] U/L, p=0.02) were greater after paricalcitol. More subjects experienced iPTH decrease in VDRA group (71% vs. 39%, p=0.03). The variation in CAVI and the incidence of hypercalcemia and hyperphosphatemia were similar. Conclusions. It seems that secondary hyperparathyroidism was more efficiently treated by VDRA, whereas cholecalciferol better corrected the calcidiol deficiency in non-dialysis CKD.

for non-functioning pituitary macroadenomas (NFMAs) is still under debate. Aim. To appreciate the best timing for postoperative high voltage radiotherapy (hRT) in different type of NFMAs (classified using immunohistochemistry (IHC)). Subjects and Methods. Of 97 patients with a remnant (>1 cm) and IHC for anterior pituitary hormones, 41 patients (groups A & B) were submitted to hRT and followed up at least 5 years. RT was performed in 20/41 patients (Group A) within the first year after surgery, 21/41 patients (Group B) afterwards while in control group C, 56 patients were followed up without hRT. The progression of postoperative remnant was defined as a change of minimum of 25% of any diameter (transversal or vertical) by serial imaging studies. Results. The IHC of NFMAs revealed the following: 38 (39%) null cell, 29 (30%) gonadotropinomas, 12 (12%) silent plurihormonal, 11 (11%) silent corticotroph and 7 (7%) silent GH/PRL adenomas. Immunoreactive adenomas have relapse rate higher than null cell adenomas (ACTH> GH/ PRL> FSH/ LH> null cell) with a significant rate for silent ACTH 6/8 (75%). The null cell adenoma relapse rate was 6/23 (26%), p<0.009 in group without hRT. The relapse rate was significantly lower in group AB with hRT than in group without RT (p=0.025), at five years. Immediate hRT (applied within in first years) improved the control of the tumour growth in 90% (18/20) cases. In the group A, 10 % (2/20) patients relapsed than 24% (5/21) patients in group B and 39% (22/56) patients, Group C. Conclusion. An optimal time for radiotherapy is within the first year after the partial surgical removal of NFMAs, particularly if a large amount of residual tumour remains. Patients with silent corticotroph adenoma require special attention.

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