Laboratory examination showed normal thyroid function and cortisol levels, yet estradiol levels were elevated at 128 pmol/L (less than 115 considered normal).
The patient underwent a pelvic ultrasound that showed maturation of the uterus with enlarged follicles of the right ovary. A brain MRI was determined to be normal, and skeletal survey radiographs showed normal bone age of the metacarpal and carpal bones.
The patient subsequently underwent 99mTc MDP bone imaging with xSPECT BoneTM performed on a
Symbia IntevoTM SPECT/CT scanner.
Figure 1: Whole-body planar bone imaging shows increased uptake of 99mTc MDP on the outer aspect of the upper wall of the right orbit, left temporal bone, sagittal sutures in addition to the left upper ulna, left femoral head and trochanter, and the left mid-tibia. The remaining skeletal system showed physiologically increased uptake in the metaphyseal regions of the long bones, as expected for the age of the patient. No abnormal hypointense area was visualized.
The clinical presentation of MAS includes three characteristics: café-au-lait skin spots, poly-fibrous dysplasia (PFD), and early on-set puberty. Diagnosis can be made if patients present with these characteristics.
Additionally, children with MAS may also be accompanied by endocrine symptoms including hyperthyroidism, Cushing syndrome, hypophosphatemia, acromegaly, hyperparathyroidism, prolactinoma, as well as cardiopulmonary disease, chronic hepatobiliary disease, gastrointestinal polyps, thymus hyperplasia, cardiac hypertrophy, and arrhythmia. In some cases, sudden death may occur.2
Skeletal abnormalities, such as PFD, commonly occur in MAS. Skeletal abnormalities in children usually occur between the ages of 3-10 and all bones can be affected. The pathological change in bone tissue is due to the replacement of normal bone tissue by fibrous connective tissue and scattered immature bone tissue. Such bone damage can be locally accompanied by liquefaction and cystic transformation or hemorrhage. Pathological fractures often occur although malignant transformation is rare.
In this particular case, X-ray and CT findings of the fibrous dysplasia in the ulna showed the lesion was located in the medullary cavity with expansive osteolytic changes, thinning of the bone cortex, and blurring of the trabecular bone structure with ground-glass changes.3 Children often present to physicians for abnormal bone development, so imaging findings are critical for the diagnosis of this disease. Comprehensive assessment of skeletal abnormalities is crucial for the diagnosis of MAS, assessing the prognosis of patients, and making treatment decisions.
Although MAS is relatively rare, it should be taken into consideration when the bone shows diffuse involvement with poor fibrous structure accompanied by café-au-lait skin spots and early-onset puberty.
The advantage of whole-body bone imaging is its ability to help show bone abnormalities in a single scan.4 SPECT/CT shows changes in bone density and other related morphological changes, along with abnormal skeletal metabolism corresponding to the microstructural changes. In this case of MAS, the whole-body bone imaging showed increased distribution of 99mTc MDP on the outer upper wall of the right orbit, left temporal bone, sphenoid, left upper ulna, left femoral head, and left middle tibia. xSPECT Bone shows sharp definition of individual skeletal lesions that closely correspond to CT changes.
Scanner: Symbia Intevo 16
5 mCi (185 MBq) 99mTc MDP
60 eff mAs
Scan speed: 12 cm/min
xSPECT Bone tomography
Two detector acquisition,
matrix 128 x 128, 60°/stop,
30 s/stop, 30 stops/detector
• Planar imaging: 10 min
• xSPECT Bone tomography: 17 min
The outcomes achieved by the Siemens Healthineers customers described herein were achieved in the customer’s unique setting. Since there is no
“typical” hospital and many variables exist (eg, hospital size, case mix, level of IT adoption) there can be no guarantee that others will achieve
the same results.