|Clinical manifestations and diagnosis of gonadotroph and other clinically nonfunctioning adenomas|
CLINICAL PRESENTATION - Gonadotroph and other clinically nonfunctioning adenomas usually come to clinical attention when they become large enough to cause neurologic symptoms. They may also be recognized when an imaging procedure of the head is performed for an unrelated reason or, uncommonly, because of hormonal hypersecretion (show table 1).
Neurologic symptoms - Impaired vision is the most common symptom that leads a patient with a gonadotroph or other clinically nonfunctioning adenoma to seek medical attention . Visual impairment is caused by suprasellar extension of the adenoma that compresses the optic chiasm. The most common complaint is diminished vision in the temporal fields (bitemporal hemianopsia). One or both eyes may be affected, and, if both, to variable degrees. Diminished visual acuity occurs when the optic chiasm is more severely compressed. Other patterns of visual loss may also occur. Thus, an intrasellar lesion should be suspected when there is any unexplained pattern of visual loss.
The onset of the deficit is usually so gradual that many patients do not seek ophthalmologic consultation for months or even years. Even at this time, the reason for the deficit may not be recognized, unless a visual field examination is performed, further delaying the diagnosis.
Other neurologic symptoms that may cause a patient with a gonadotroph adenoma to seek medical attention include:
- Headaches, presumably caused by expansion of the sella. The quality of the headache is not specific.
- Diplopia, induced by oculomotor nerve compression resulting from lateral extension of the adenoma.
- Cerebrospinal fluid rhinorrhea, caused by inferior extension of the adenoma.
- Pituitary apoplexy induced by sudden hemorrhage into the adenoma, causing excruciating headache and diplopia.
Incidental diagnosis - The common use of magnetic resonance imaging to evaluate symptoms in the head or neck has resulted in the incidental discovery of many intrasellar lesions. Although many of these tumors are small and not clinically functioning, some are more than 1 cm in diameter and can be recognized as gonadotroph adenomas by the procedures described below. (See "Pituitary incidentaloma").