A 50 year-old woman presented to the clinic with the
complaints of insidious onset of facial plethora, weight gain,
and hypertension for more than 3 years.
This 50 year-old, previously well woman noted to have
hypertension that made her take anti-hypertensive agents about
3 years ago. She also noticed her cheeks frequently turning
flush with a sense of facial and neck swelling. She gained
weight steadily in these 2 years and found the fat gathering
mainly at the face, neck, and truncal region. Her skin felt
greasy, with more acne formation than before and she also
noted to have a proximal muscle weakness with a difficulty in
lifting heavy matter.
Physically, she had a puffy and
plethoric face (Fig.1
), truncal obesity, and a buffalo hump. The height was 157 cm
and the weight was 62.5 kg. The blood pressure was 160/90mmHg,
the pulse was 88, the temperature was 37.0℃, and the
respirations were 22. Her face and upper chest revealed
acneiform eruptions. A non-tender, elastic nodule about 1 cm
in diameter was found at the left thyroid lobe. Her abdomen
was fatty with whitish but no purple skin striae. The other
physical examinations were unremarkable.
Laboratory tests were performed
(Table 1-3).
Table 1.
Hematologic Laboratory Values.
___________________________________________________
|
RBC M/μL |
Hb g/dL |
Hct % |
MCV fl |
Platelet k/μL |
WBC k/μ |
MCHC g/dL |
On Admission |
4.66 |
13.8 |
40.6 |
87.1 |
301 |
16.66 |
34 |
|
Seg % |
Eos % |
Baso % |
Mono % |
Lym
% |
|
|
On Admission |
92.5 |
0 |
0.1 |
1.9 |
5.5 |
|
|
___________________________________________________
Table 2. Blood
Chemical and
EnzymeValues.
___________________________________________________
BUN mg/dL |
Cre mg/dL |
Alb g/dL |
Glo g/dL |
GOT U/L |
GPT U/L |
LDH U/L |
T-Bil mg/dL |
16.6 |
0.7 |
4.1 |
3.0 |
12 |
16 |
439 |
1.0 |
Na mmol/L |
K mmol/L |
Mg mmol/L |
Cl mmol/L |
Ca mmol/L |
TG mg/dL |
Cho mg/dL |
AC Glu mg/dl |
149 |
3.6 |
0.96 |
106 |
2.34 |
81 |
208 |
117 |
___________________________________________________
Table
3. Urinalysis.
___________________________________________________
Appearance |
Yellow; clear |
Bil |
- |
Sp Gr. |
1.038 |
Nitrite |
- |
PH |
6.5 |
RBC |
- |
Protein |
- |
WBC |
0-1 |
Glu |
≧1.0g/dL |
Epi |
0-1 |
Ketone |
- |
Cast |
- |
OB |
- |
Crystal |
- |
Urobilinogen |
1.0EU/dL |
|
|
Thyroid function test:
Free T4: 1.19 ng/dL (0.6-1.75) |
TSH: 0.274 |
μIU/mL (0.1-4.5) |
Thyroid echo:
Left multinodular goiter
Thyroid aspiration cytology: negative for
malignant cells, sheets of follicular cells with colloid.
___________________________________________________
Table
4. Adrenocortical
function.
___________________________________________________
|
ACTH pg/ml |
Cortisol mcg/dl |
On 2nd day of admission 9:25AM 4:23PM |
20.5 351 |
>100 82
|
On 5th day of admission 8AM 4PM
|
40.3 16.9 |
50.0 15.3 |
On 6th day of admission 8AM* |
|
5.3 | ___________________________________________________ *1 mg overnight dexamethasone
suppression test.
Brain MRI (on 5th day of
admission): focal lesion was shown in the pituitary gland on
the right side with presentation of less, and delayed
enhancement. It measured about 0.5 cm in diameter (Fig.2
).
<Course and
Treatment>
She was diagnosed to have
Cushing's disease by clinical and laboratory examinations.
Brain MRI revealed a microadenoma at the right lobe of
anterior pituitary gland. Therefore the patient was referred
to the neurosurgeon for surgical intervention of pituitary
adenoma. Via endonasal, trans-sphenoidal route, adenomectomy
and hemihypophysectomy were performed smoothly on the 10th day
of admission. The pathology of the resected tumor showed a
pituitary adenoma that was stained positively for ACTH. She
was discharged a week later and put on replacement therapy of
cortisone acetate and thyroxine. A follow up ACTH level on the
13th post-operative day was low
(<1.0 pg/ml).
OP finding
(On 10th day of admission):
poor pneumatization of right half of sphenoid sinus; thin
sellar floor (sella not enlarged); a 0.5 cm yellowish soft
nodule at right margin of the gland, noted after partially
removal of the normal gland. Pathology
(On
10th day of admission): a pituitary
adenoma with eosinophilic and clear cytoplasm. Scattered ACTH
positive cells can be seen.
病案分析
本案例為一庫欣氏病的患者,在臨床上,庫欣氏症候群的診斷,有兩個最重要的盲點:第一、是要如何區分病人之過量的皮質素分泌,是屬於病理性的,而非只是生理上為了因應壓力或其他原因,所引起的皮質素過量分泌;第二、是要確認病理性皮質素過量的原因為何。而其原因,則包括醫源性的皮質類固醇使用,腎上腺皮質腺瘤或腺癌,腦下垂體腺瘤,或是其他異位性腫瘤所引起的腎上腺皮質促素(ACTH)或皮促素之釋放激素(CRH)所導致的皮質素過量分泌。患者可先接受1
mg
dexamethasone抑制試驗,若為陽性(無法被抑制到<5μg/dL),可再讓病患留取24小時尿液,檢測其中free
cortisol量,來初步確認是否為病理性的皮質素過量分泌。其次則可用high-dose 2 mg q6h
dexamthasone suppression
test共48小時,來大致區分是pituitary或adrenal、ectopic來源的皮質素過量分泌,若是腦下垂體腺瘤引起者,或少數情況下由ectopic
carcinoid所引起者,通常可以被抑制到小於10%基礎分泌量,亦即,大於90%以上的suppression。若生化檢驗及影像學檢查,如:腦下垂體核磁共振檢查,均難以區分是腦下垂體腺瘤或異位性腫瘤所引起時(有50%腦下垂體腺瘤所導致的皮質素過量分泌,其腫瘤大小<
5mm),可用Inferior petrosal venous
sampling方式來區分。因為臨床上腦下垂體腺瘤所引起的庫欣氏病最為常見,約佔所有病例的70%,且手術預後是較好的,正確區分及鑑別診斷是相當重要的工作。
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