Clinically Silent Somatotropinomas May Be Biochemically Active

Abstract

The diagnosis of acromegaly is suspected based on the typical clinical presentation and is subsequently confirmed biochemically by elevated GH and IGF-I concentrations. We report three female patients with pituitary tumors who presented without any signs or symptoms of acromegaly but with elevated IGF-I levels. Plasma GH was measured every 10 min for 24 h, and an oral glucose tolerance test was performed. All patients had abnormally elevated mean and trough plasma GH levels as well as post-glucose nadir GH concentrations. All patients had magnetic resonance imaging scans revealing pituitary tumors and underwent transsphenoidal surgery. Histologically, they had GH-producing pituitary tumors. Plasma IGF-I levels returned to normal in two patients after surgery. Some pituitary adenomas are true GH-secreting tumors despite not being accompanied by obvious clinical stigmata of acromegaly. Natural history of this disease is unknown because of the small number of reported patients and inconsistent results of biochemical testing. Based on the results of this and previous reports, we propose that all patients with known pituitary tumors, especially younger women with normal or mildly elevated prolactin level, be evaluated for GH excess.

A complex case of Multiple Endocrine Neoplasia type 1 with Metastatic Parathyroid Carcinoma

“…Though her lack of symptoms could be due to early diagnosis, however, the fact that her hormone levels were significantly high does raise the possibility of silent acromegaly [23,24].…”

“…Silent somatotroph pituitary tumours are defined as GHsecreting tumours with no clinical stigmata of GH excess [24][25][26]. Random GH and IGF-I values in these patients varied from mildly elevated to normal [27].…”

Abnormal dynamics of growth hormone after thyrotropin-releasing hormone loading test, gonadotropin-releasing hormone loading test, and oral glucose tolerance test in mixed gonadal dysgenesis with a pituitary lesion

“…Nevertheless, it may be evoked by a GHsecreting adenoma, although the pathology of pituitary lesion is not verified. Clinically silent somatotroph adenoma has been reported by several investigators, and this condition frequently has menstrual disorder [1][2][3][4][5][6][7][8][9][10].…”

Biochemical acromegaly in patients with prolactinoma during treatment with dopaminergic agonists

“…Concomitant hypersecretion of GH in prolactinomas cannot be suspected because of the predominance of clinical manifestations of hyperprolactinemia (3), and there is currently no recommendation for the routine investigation of acromegaly in patients with prolactinomas (1).…”