Immunochistochemical characteristics of blood vessels in non-visualized and visualized on MRI pituitary adenoma in patients with Cushing’s disease

Abstract

Background. Regardless of improvements in MRI, up to 20% of ACTH-secreting pituitary tumors are only identified at surgical exploration. Aim. Тo estimate whether there is any difference in blood vessels and the subsequent ability to uptake contrast agent in visualized microadenoma as compared to non-visualized on MRI ACTH-secreting pituitary tumors.Material and methods. Retrospective evaluation of ACTH-positive pituitary tumors from patients with Cushing’s disease (n=39) with either non-visualized pituitary tumor on MRI (n=17) or pituitary tumor less then 25 mm (n=22). MRI was performed using Siemens Magnetom Harmony 1.0T with gadolinium. Selected tumors were stained with anty-СD34 antibody (clone QBEnd/10, RTU, Leica) and anty-D2-40 antibody (clone D2-40, RTU, Dako). We evaluated the microvessels density and measured the diameter of larger and smaller vessel.Results. The microvessels density were not different in subject with visualized [123 (77; 136)] and non-visualized [112 (110,0; 126,5)] pituitary adenomas as well as number of slit-shaped vessels [32 (5; 50) in visualized vs 25 (5; 50) in non-visualized pituitary adenoma]. The diameter of these vessels also did not differ: the diameter of the largest vessels in patients without visualization 53 µm (32,5; 63,5) vs 33 µm (30,0; 51,5) the average diameter of the blood vessels 15 µm (14,5—26,0) against 13 µm (12; 14).Conclusions. The diameter and microvessels density in ACTH-producing pituitary adenoma does not affect the visualization of adenoma on MRI in patients with Cushing ‘s disease.