Abstract
Background
Non-functioning pituitary adenomas (NFPAs) are characterized by the absence of clinical and biochemical evidence of pituitary hormone hypersecretion, and these tumors constitute approximately one third of all the tumors of the anterior pituitary. Recently, hormonal deficiencies have gradually evolved to become the leading presenting signs and symptoms in patients with NF-PAs. We investigated pituitary hormonal insufficiencies according to the magnetic resonance imaging (MRI) findings in patients with NFPA.
Methods
We evaluated the patients who were newly diagnosed with NFPA from 1997 through 2009. Among them, we analyzed 387 patients who were tested for their combined pituitary function and who underwent MRI. The severity of the hypopituitarism was determined by the number of deficient axes of the pituitary hormones. On the MRI study, the maximal diameter of the tumor, Hardy's classification, the thickness of the pituitary gland and the presence of stalk compression were evaluated.
Results
The mean age was 46.85 ± 12.93 years (range: 15–86) and 186 patients (48.1%) were male. As assessed on MRI, the tumor diameter was 27.87 ± 9.93 mm, the thickness of the normal pituitary gland was 1.42 ± 2.07 mm and stalk compression was observed in 201 patients (51.9%). Hypopituitarism was observed in 333 patients (86.0%). Deficiency for each pituitary hormone was most severe in the patients with Hardy type IIIA. Hypopituitarism was severe in the older age patients (P = 0.001) and the patients with a bigger tumor size (P < 0.001) and the presence of stalk compression (P < 0.001). However, the patients who had a thicker pituitary gland showed less severe hypopituitarism (P < 0.001). Multivariate analysis showed that age, tumor diameter and the thickness of pituitary gland were important determinants for pituitary deficiency (P = 0.004, P < 0.001, P = 0.022, respectively).
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![]() | Fig. 2.(A) An example case of normal stalk morphology. (B) An example case of stalk deviation; The stalk attachment of the pituitary gland deviated from the midline to the right side (dotted line). (C) An example case of stalk compression; Normal stalk morphology are not seen. |
![]() | Fig. 3.Measurement sites of the pituitary gland. (A) Maximal height were measured in coronal plane. (B) Maximal height were measured in sagittal plane. |
Table 1.
Interpretation of combined pituitary function test
Nadir glucose should be less than 40 mg/dL in nondiabetics or less than 50% of basal level in diabetics for appropriate stress induction. GH, growth hormone; ACTH, adrenocorticotropic hormone; i.v., intravenously; PRL, prolactin; TSH, thyroid-stimulating hormone; TRH, thyrotropin-releasing hormone; FSH, follicle-stimulating hormone; LH, luteinizing hormone; LHRH, luteinizing hormone-releasing hormone; RI, regular insulin.
Table 2.
Baseline characteristics of 387 patients
Table 3.
Pituitary insufficiency in different age groups
Age | Number of patients | Number of deficient hormone |
---|---|---|
< 20 | 4 | 1.75 ± 2.06 |
20 – 29 | 44 | 1.93 ± 1.60 |
30 – 39 | 66 | 2.33 ± 1.53 |
40 – 49 | 101 | 2.29 ± 1.46 |
50 – 59 | 107 | 2.69 ± 1.53 |
60 – 69 | 52 | 2.73 ± 1.49 |
≥ 70 | 13 | 3.85 ± 1.57* |
Table 4.
Pituitary Insufficiency depending on Tumor Size and Hardy's Classification
Number of patients | Number of deficient hormone | ||
---|---|---|---|
Tumor size | < 10 mm | 9 | 0.44 ± 0.52 |
10 – 20 mm | 72 | 1.35 ± 1.42 | |
20 – 30 mm | 154 | 2.51 ± 1.53** | |
30 – 40 mm | 101 | 3.03 ± 1.29** | |
40 – 50 mm | 42 | 3.12 ± 1.23** | |
≥ 50 mm | 9 | 3.56 ± 1.33** | |
Hardy's classification | I II IIIA | 21 58 101 | 1.19 ± 1.60 1.74 ± 1.58 2.88 ± 1.43** |
IIIB | 153 | 2.65 ± 1.51** | |
IV | 54 | 2.48 ± 1.35* |
Table 5.
Pituitary insufficiency depending on pituitary gland thickness an stalk morphology
Number of patients | Number of deficient hormone | ||
---|---|---|---|
Thickness of | ≥ 5 mm | 29 | 1.21 ± 1.55 |
pituitary gland | < 5 mm | 120 | 2.11 ± 1.57* |
Not seen | 238 | 2.81 ± 1.45* | |
Presence of stalk | Normal stalk | 40 | 1.18 ± 1.41 |
compression | Stalk deviation | 146 | 2.29 ± 1.59* |
Stalk compression | 201 | 2.87 ± 1.38* |
Table 6.
Multiple linear regression for variables independently associated with impaired pituitary function