Clinical features of inferior and lateral invasive expansion of GH-producing adenoma
T. Asano, H. Yamada, A. Aoki, M. Sasaki, A. Ikoma & S. Ishikawa
The present study was undertaken to determine morphological and biochemical characteristics of GH-producing tumor. We collected consecutively 15 patients with acromegaly, and they were 6 males and 9 females with the ages of 58.5±9.9 years. As for tumor size, 7 patients had macroadenoma, 5 had microadenoma and three had empty sella with some atypical expansions. Only 3 patients had intrasellar tumor and 2 patients had empty sella in MRI finding. Other 10 patients had atypical tumor growth and expansion. Invasive inferior expansion into sphenoid sinus with macroadenoma was found in 3 patients. Inferior and lateral expanded extrasellar tumor with empty sella was found in 2 patients. Unilateral or bilateral expansion along with microadenoma and macroadenoma was obtained in 3 patients. Other 2 patients had latero-inferior expansion, and both superior and inferior expansion of macroadenoma.
Endocrinological studies showed that serum GH and insulin growth factor (IGF1) levels were 33.3±32.5 ng/ml and 699.3±299.3 ng/ml in 7 patients with macroadenoma, 8.7±7.4 ng/ml and 586.5±35.2 ng/ml in 5 patients with microadenoma, 7.5±2.9 ng/ml and 433.2±91.0 ng/ml in 3 patients with empty sella and inferior expanded tumor. The increases in hormonal levels seemed to be dependent on tumor volumes, and did not relate with the direction of extrasellar expansion. Serum prolactin was mildly elevated to 17.49 to 90 ng/ml in 7 patients, that means simultaneous secretion of prolactin with GH in acromegaly. Hyperprolactinemia were not associated with compression of pituitary stalk and inhibition of prolactin-inhibiting factor. The present findings indicate that GH-producing tumors easily grow to macroadenoma, and the tumor growth may mainly develop to the inferior and/or lateral expansion by destroying bony tissues of sella turcica. The tumor expansion could be different from that of other functioning and non-functioning pituitary tumors in which tumors grow superiorly.
Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.
Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.