411
CT Appearance of the Adolescent and Preadolescent
Pituitary Gland
Robert G . Peyster,' Eric D. Hoover,' Richard R. Viscarello ,' Thomas Moshang ,2 and Marvin E. Haskin '
Coronal computed tomographic scans of the pituitary gland in
27 normal children, adolescents, and young adults (ages, 8-21
years) and in a comparison group of adults (ages, 24-91 years)
were evaluated retrospectively to test the applicability of published criteria for size and configuration of normal adult pituitary
glands to younger patients. Statistically significant differences
were found between the two groups, indicating that the pituitary
gland in adolescents, particularly girls, is larger than in younger
or older patients. The authors suggest that pubertal pituitary
hyperplasia accounts for these findings . They conclude that
standards for normal pituitary glands are probably inappropriate
for adolescents.
Thin coron al-section co mpu ted tomograph y (CT) is th e most
accurate radiolog ic modality for evalu ation of th e pituitary gland
[1 - 4] and is th e onl y c urrent radiolog ic tec hnique for im aging th e
gland's morph ology. Th e CT appearance of the norm al pituitary
gland has been studied in adult pati ents with out c linical eviden ce of
pituitary dysfun cti on [4 , 5] , providin g stand ard s of norm ality fo r
gland height and shape [4]. The se c riteri a have been wid ely employed for CT id entificati on of enl arg ed gl and s containing mi c road enomas [1- 5]. We kn ow of no CT or autopsy stud y th at has
spec ifically examin ed th e appearance of th e pituitary gland in
children or ad olescents with out pituitary dysfun ction. We noted
several cases of pituitary gland s with abn ormal heig ht and / or
shape, according to th e previously mentioned s t a nd a rd ~, in yo un g
pati ents in wh om th ere was no cl inica l suspici on of pituitary adenoma. Uncertain of th e appli cabilit y of th ese standard s to yo un ger
pati ents, we undertook a stud y to determin e th e CT appearance of
the normal pituitary gland in c hildren and ad olescents.
Materials and Methods
Review of our fil es yielded 27 coron al CT scans th at inc lu ded
adequate visualizati on of th e pituitary gl and in pati ents between 8
and 21 years of age w ho had no reasonabl e suspi c ion of harborin g
pituitary pathology (group 1). A com pari son group (g roup 2 ) o f 2 7
adult scans was assembled from th e fil es . Criteri a for se lecti on were
adequate co ron al visualizatio n of th e pituitary gl and and lack of any
clin ical suspic ion of pituitary path ology . Th e age range for subjects
in group 2 was 24 - 9 1 years. Most pati ents in both groups had been
examin ed initiall y because of clinical suspi c ion of path olog y involving the orbits, optic c hi asm, cave rn ous sinuses, or nasoph arynx.
All studi es we re perform ed on a GE CI T 8800 scanner w ith 1 .5
or 5 mm co ronal sections through th e se ll a turc ica foll owing intravenous co ntrast infu sion (Con ray 60 % , 150 ml ; Mall inckrod t).
Th e pitu itary glands in both groups we re evalu ated for height and
superi or co ntour . Gland height was measured at the mid line, excep t
in co nvex glands, where it was taken at the hi ghest point. The
supe ri or co ntour was described as upwa rd ly concave, co nvex, or
fl at. Al so noted we re any cases of unu sually narrow glands (i n
transve rse diameter). Pi tuitary glands in both groups we re categorized as norm al, questi onabl e, or abn orm al accord in g to th e cri teria
prov ided by Syvertse n et al. [4]. " Norm al " glands had fl at (fi g . 1 A)
or co ncave (fi g. 1 B) superior margin s and measured less than or
equal to 6 mm in height for males and 7 mm fo r fe males. " Ab normal"
gland s (Fi g . 1 C) all had convex superi or margin s and height s
exceed in g 6 mm for males and 7 mm fo r females. Glands categori zed as " questi onabl e" (fig . 1 D) all had co nvex superior margins
and heights near the upper limi ts of normal (fo r males , 5.5-6 mm ;
for females, 6.5- 7 mm) .
Results
Th e results for child ren and adolescents (group 1) are show n in
tabl e 1 and results for ad ults (g roup 2) are show n in table 2.
Mean gland height for group 1 females was significan tl y greater
th an for group 2 females ( p < 0 .02). Mean gland height for group
1 males was greater th an for group 2 males. Th ese di ffe rences are
amplfied when group 1 is subd ivided into age groups . In boys and
girl s 8 -1 2 yea rs of age, gland heights we re simil ar to those in adu lts
of eac h gender . In girl s 13- 17 yea rs of age , a d ramatic inc rease in
mean gland height is noted, with a subseq uent small decrease in
mean gland height among yo un g wo men 18-21 years of age. A
hi ghly significant overall difference in gland height is fou nd among
girls 13 - 2 1 yea rs of age compared w ith adult females in group 2
( p < .001). For boys in group 1 , a small inc rease in mean gland
height is noted in ages 13-1 7 yea rs co mp ared with ages 8- 1 2
years. Th e mean gland height co ntin ues to inc rease among yo un g
men 18 - 21 years of age. The mean gland height for boy s 13-2 1
years of age is significa ntl y g reater th an for ad ult males in group 2
( p < 0. 05) .
Differences betwee n groups 1 and 2 are also noted in the con tou r
of the supe ri or margin of th e gland. A co nvex superior margin was
mu c h more co mmon in group 1 (42 % ) th an in group 2 (12% ). A
co ncave superior margin was relative ly unco mm on in c hil d ren
(16 % ) compa red w ith ad ults (52 % ). All glands wi th co nvex supe ri or
marg in s in group 1 were fou nd in patien ts 13-2 1 years of age and
we re more comm on in fe males than in males.
Th e CT ratin gs of glands also revealed major dissimilariti es
I Department of Di ag nostic Rad iology , Hahn emann University Med ical Coll ege and Hospital , 230 N. Broad St. , Ph il adelph ia, PA 19 102. Add ress reprint
requests to R. G. Peyster.
2 Departm ent of Pediatri cs, Hahn emann University Medica l Co llege and Hospita l, Phil adelphia, PA 19 102.
AJNR 4:411-414, May / June 1983 0 195- 6 108 / 83 / 0403-041 1 $00 .00
© Ameri can Roe ntg en Ray Soc iety
PITUITARY GLAND AND PARASELLAR LESIONS
412
AJNR:4, May/ June 1983
Fig . 1. -CT scans of p ituitary gland .
A, ··N orm al " gland w ith flat superi or
margin. Gland height, 4 mm . 5 mm coronal section , mag nification x2.3. B,
" Norm al" gland with concave superior
margin . Gland height 3.5 mm. 1.5 mm
coronal section , mag nification x 2. C,
"Abnorm al " gland in 21 -year-old man .
Convex su perior margin . Gland height,
8 mm . 1.5 mm co ronal section, magnification x3. (Note c ursor used for gland
height measurement.) D, " Qu estionable" gland in 14-year-old boy . Slightly
convex superior marg in . Gland height.
6 mm . 1.5 mm coronal section, mag nification x 2.
A
B
c
o
TABLE 1: CT Appearance of Ad o lescent and Preadolescent Pituitary Gland
Appearance of Gland
Gender: Ag e Group (Yea rs)
No. Cases
Mean Heighl ± SO
(mm)
CT Raling : No. ( % )
Shape : No. ( % )
Flat
Convex
Concave
Normal
Questionable
Abno rmal
F e m a le:
8-12
13- 17
18-2 1
S ubtota ls
3
3
5
11
±
±
±
6.6 ±
4 .0
8 .2
7.3
0
0
3
0
0
0
2
3
4
2
5
4
4
3
0
0
0
2
1 .7
1.4
0 .6
0
3
4
3
0
0
2.0
7
3
3. 0
4.3
5 .7
± 0 .8
± 1 .2
± 1 .3
0
1
3
2
3
3
2
1
0
± 2. 1
± 2.1
8
3
11
2
2
4 (16)
15 (58)
4 (15)
7 (27 )
M a le:
8 -1 2
13-17
18-21
4
6'
6
Subtotals
16 '
4 .5
Totals
27*
5.4
4
11 (42)
11 (42)
. A 1 5-year-old boy with an 18 mm sellar-suprasellar mass was excluded from all calcu lations.
PITUITAR Y GLAND AND PARASELLAR LESIONS
AJNR:4 , May / June 1983
413
TABLE 2: CT Appearance of Adult Pituitary Gland
Appea rance of G land
Gender. Mea n Age (Years)
± SO
No.
Cases'
(mm)
Females, 51 ± 22
Male, 55 ± 19
Totals
Shape; No . (% )
Mea n Height ± SO
Convex
Flat
15
12
4 .8 ± 1.7
3.5 ± 2. 0
2
6
3
27
4 .3 ± 2.0
3 (12)
9 (36)
CT Rating ; No . ( % )
Concave
6
7
13 (52 )
Norm al
Questionable
13
11
1
0
24 (89)
1 (4)
Abno rm al
2 (7)
• Two cases (one fema le. one ma le) of empty se ll a were exc luded from stati sti cs involving gland height and shape .
between groups 1 and 2 (p < 0 .02). Th ere were eight cases (30%)
in group 1 with abnormal gland height and 12 with co nvex superior
marg in s, inc luding a 15-year-old boy who had an 18 mm high sellarsuprasellar mass and was excluded from all furth er ca lc ulations .
The co rrec ted inc idence of abnormal cases (i.e. , cases suspect for
the presence of microadenomas, based on accepted cri teria) in
group 1was 27% , co mpared w ith 7% in group 2. Th ere was also a
greater inc idence of questi onable or borderlin e cases in group 1
(15%) th an in group 2 (4 %). As wo uld be expected from th e analysis
of gland height and shape, all the abnormal and questionable cases
in group 1 occurred in pati ents 13 - 2 1 years of age and were mo re
common in females. Th e inc idence of abnormal and questionabl e
cases in males 18- 2 1 years of age was greater th an in yo unger
male subjects.
Unusually narrow sella turcicas and pituitary glands were noted
in eight subjec ts in group 1. Five of the se subjects were rated
normal, two questionable, and one abnorm al. In group 2, one
subject had a narrow sella and pituitary gland and was rated norm al.
Clinical and laboratory follow-up evalu ation of two of th e abnormal
and three of th e qu estionable cases in group 1 failed to demonstrate
any evidence of pituitary dysfu nct ion .
Discussion
In 1979, Syvertsen et al. [4] reported th eir finding s on CT
examination of th e pituitary gland in 20 pati ents 6- 74 years of age
who had no c linical suspi c ion of harborin g a pituitary adenoma . All
20 patients had fl at or co ncave superior gland margin s. Th e mean
gland heights were 4 .8 mm (range , 2.7-6 .7 mm) for fema les and
3.5 mm (rang e, 1.4-5.9 mm) for males. In four surgically proven
cases of microadenoma, two had co nve x upper g land margin s and
all four had gland heights exceeding 8.8 mm . On the basi s of these
findings, th e authors proposed that g lands exceed ing 7 mm in
height for females and 6 mm for males be co nsidered abnormal.
They also co ncluded th at a co nvex co ntour of the superior margin
of the gland is an abnormal finding. Th ey did not elaborate on th e
age distribution of th ei r 20 patients, nor did th ey mention th e
number of c hildren inc luded . In 1982 , Chambers et al. [5] studi ed
by CT the pituitary glands of 50 subjects who had orbital co mplaints
but were without c linical symptoms of pituitary disease . The age
range of these patients was not given. The authors found the
superior gland margin to be flat or co ncave in 96% and the mean
gland height to be 5 .3 mm ± 1.7 mm . In the same stud y, 100
au topsy specimens of pituitary glands from pati ents without known
clinical pituitary abno rmaliti es were evaluated . The subjects were
9- 82 years of age (38 females and 42 males) . The superior margin s
of these glands were flat or co ncave in 94% and the mean gland
height was 5 .2 mm ± 2 mm . Again , the age range of th e patients
was not mentioned . In general, the finding s of Ch ambers et al. are
in agreement with those of Syvertsen et al. Muhr et al. [6], in an
autopsy series of 205 pituitary glands, found a mean gland height
of 6 mm ± 1 mm for females and 5 mm ± 1 mm for males. Glands
with co nvex upper margins were noted in 4 % of specimens th at did
not contain sizable lesions. On ly two or three pati ents und er 2 1
yea rs of age appeared to have been inc luded in thi s stu dy and the
ages of th ose wit h convex glands were not provid ed . Mc Lachlan et
al. [7] found th e upper gland margin to be co ncave in most specimen s in an autopsy seri es of 50 cases with no hi story of pituitary
dysfunc tion .
We know of no previous studi es, either by CT or autopsy, of th e
appearance of th e norm al pituitary gland in c hil dhood or adolesce nce. Although th e process of selec ti on of the 27 pati en ts inc luded
in group 1 cannot be co nsidered random, our subjects we re selected in a manner similar to that employed by Syvertsen et al. [4]
and Chambers et al. [5]. Th e comparison group of adu lt pati en ts
(group 2) was inc luded to nullify th e effect of any idiosyncrasi es in
ou r interpre tation of CT scans or in our scanning technique. Th e
findings regarding gland heigh t and superior margin con tour in our
ad ult group were similar to those of oth er researchers [4, 5], thu s
minimizin g th e possibilit y that differences between ou r group 1 and
group 2 refl ect an atypica l adult sample. Th e 7% inc idence of
abnorm al glands in group 2 falls wi thin the reported range for
inc id ental microadenomas (2.7 %- 27 %) [8].
Th e 4 x higher inc idence of abn orm al cases in group 1 compa red
with group 2 is striking and statisti cally significant ( p < 0 .02 ). Th e
dissimilarity between groups 1 and 2 is even more noticeab le when
group 1 is subdi vided into age groups, whereby it is demonstrated
th at th e abnormal and questi onable gland s occu r exclu sive ly in
subjec ts older th an 1 2 years of age, and more co mmon ly and earli er
in females than in males. It is unlikely th at these statisti cs ca n be
explained by th e presence of inc idental microaden omas. Pituit ary
adenomas are generall y co nsidered rare in child ren and adolesce nts , especially w hen th ere is no c linica l evidence of pituitary
gland dysfunction [8 -12]. The inc idence of abnorm al cases in group
1 (30%) exceeds th e reported freq uency of inc iden tal microade nomas or any other sizab le pathology of th e pituitary gland [5 , 7,
9]. Clinic al and laboratory follow-up of two of th e abnorm al and
three of th e questionable cases in group 1 revealed no evid ence of
pituitary dysfu nction.
It is also implausible th at fund amental errors in the stand ard s of
normality employed for CT evaluati on of th e pitu itary gland co uld
explai n th ese finding s, since th e same c rit eri a were used for both
group 1 and group 2. However, several authors have c hallenged
certain c riteria proposed by Syvertsen et al. [4]. Taylor [1] stated
th at convexity of th e superior gland margin can be a norm al vari ant
when the width of th e gland is small. In ou r stud y, narrow gland s
we re enco untered more often in cases co nsidered normal th an in
the abnormal or questionable cases. Muhr et al. [6] reported a 4 %
inc idence of co nvex superior margin s in specimens devoid of any
sizable pathology and co nc luded th at thi s findin g ca n be a normal
variant. Gardeur et al. [1 3] stated that no stud y to date has clearly
establi shed standards of normality for th e CT appearance of th e
414
PITUITAR Y GLAND AND PARASELLAR LESIONS
pitui tary gland. since au topsy or surgical co nfirmati on wo uld be
requ ired to prove that there was no path ology present. Whil e such
co nfirmation wo uld be ideal. it is hardl y practica l.
Th e best explanati on for our finding s may be found in th e physiologica l-e ndocrin ologi cal events associated with puberty. In support of thi s hypoth esis we offer th e following : (1) No abn orm al
glands were fou nd in th e group of subjects 8-12 yea rs of age and
comprising mainl y prepu bertal c hildren. Th e mean gland heig hts for
both genders in thi s age group do not differ signifi cantly from th ose
found in ad ults in group 2. (2 ) In females 1 3 -1 7 years of age, wh o
would be expected to have entered puberty. th ere is a twofold
increase in mean gland height. Males in this age group demonstrate
a smaller inc rease in mean gland height. perh aps refl ecting
the later onset of pubert y in males [14]. (3) In males 18- 2 1 years
of age, a con tin ued increase in mean gland height is noted compared with yo unger boys. perh aps reflecting th e fact th at most
males have reac hed puberty by thi s time. (4) Th e age-related
c hanges noted in th e pituitary glands parallel th e c hange in ci rc ulatin g levels of gonadotropin s. whic h inc rease sharpl y at puberty
[15) and earli er in females [1 6). (5 ) Physiolog ica l enlargement of
the pituitary gland (h ype rpl asia) is reported to occur in pregnancy
[7. 13). anoth er developm ental peri od during whi c h increased hormonal production by th e pituitary gland is expec ted . An association
has been noted [1 7 - 1 9) between pituitary hyperpl asia and ce rtain
endocrine-defi c ient states caused by end-org an failure. su c h as
prim ary hypothyroidism or hypogonadism. presumably secon dary
to decreased negati ve-feed back inhibition on th e hypothalamu s. (6)
Costello [9) found a sharp inc rease in th e inc idence of "subclinical
adenomas " in th e pituitary gland s of c hildren beginning at about
12 or 13 yea rs of age. whi c h corresponds to th e age at whic h th e
large inc rease in mean gland height in females was noted in our
stu dy. Since it may be difficu lt to distin guish path ologicall y between
adenomas and foci of hyperplasia [1 2 . 20) . it seems likely th at
Costello may have mistaken hyperpl asia secondary to puberty for
microadenomas in th ese spec imens.
Despite th e relatively small sample. highl y significant differences
in pituitary gland size and co nfig uration between adults and pubesce nt c hild ren were noted in our study. It appears from th ese findin gs
th at th e previously described standards of norm ality for th e CT
appearance of the pituitary gland [4) are not appli cabl e to adolescents, parti cularly to adolescent females . A large cross-section al
stud y of th e si ze. sh ape . and general appearance of th e pituitary
gland would be helpful to co nfirm our fin dings and to provi de
gender- and age-related standards of norm ality for th e gland .
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