Pathologic Characteristics of Somatotroph Pituitary Tumors-An Observational Single-Center Study

The pathologic evaluation of a tumor tissue is an essential part of an acromegaly patient's assessment. This study aimed to analyze the pathologic characteristics of pituitary tumors in patients with acromegaly. The demographic data, in addition to the hormonal, imaging, and pathologic results of 120 patients with acromegaly after pituitary surgery, were extracted from the Polish Acromegaly Registry. We compared sparsely and densely granulated tumors, GH(+), mixed GH(+)/PRL(+) and plurihormonal tumors, α-subunit-positive and α-subunit-negative tumors, and tumors of various Ki-67 indices in terms of the abovementioned features. Sparsely granulated tumors were more frequent in women than in men (p = 0.001) and in younger patients (p = 0.011), and they were larger (p < 0.001) compared to densely granulated tumors. Tumors with positive α-subunit were smaller (p = 0.013), showed extrasellar extension less often (p = 0.039), and were more often densely granulated (p < 0.001) compared to α-subunit-negative tumors. Patients with a higher Ki-67 index were younger (p < 0.001) and more often diagnosed with genetic syndromes (p = 0.02); they had higher GH concentrations (p = 0.007), larger tumors (p = 0.006), and cavernous sinus invasions more frequently (p = 0.022). Conclusions: The pathologic characteristics of somatotroph pituitary tumors are associated with patient's age, sex, hormonal results, tumor size, and the degree of extrasellar expansion.