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Age / Sex : 53 / F
Chief complaint: gait disturbance 1) What is your impression?
Two weeks later, you can see the final diagnosis with a brief discussion of this case.
(Quiz는 quiz일 뿐이오니 답안은 한개만 보내주시기 바라오며, 복수의 답안을 보내주시는 분은 정답이 포함되어 있더라도 부득이 semi-correct answer로 처리토록 하겠습니다.) Courtesy: 양익, 한림대강남성심병원
Diagnosis: Primary hyperparathyroidism due to parathyroid adenoma
Discussion
Findings:
Well defined eccentrically located, expansile osteolytic
lesions in the tibia.
CT : A heterogeneous
enhancing solid mass at posterior aspect of right thyroid gland.
99m Tc – sestamibi scan
: asymmetric increased activity at the lower right thyroid lobe.
Tc 99m MDP scan :
diffuse and focal hot uptakes at skull and left tibia.
Simple : Subperiosteal resorption, particularly at the
radial shafts of the phalanges.
Salt and pepper
appearnace at skull.
Diagnosis: Primary hyperparathyroidism due to parathyroid adenoma
Discussion:
Primary hyperparathyroidism, due to
autonomous hypersecretion of PTH, usually occurs in the setting of a
parathyroid adenoma (80%) but can also be seen with parathyroid gland
hyperplasia (15%–20%) or carcinoma (<0.5%). Secondary hyperparathyroidism
results from stimulation of the parathyroid glands as a response to
hypocalcemia or due to apparent insensitivity of the parathyroid glands to
elevated serum calcium levels and dysregulation of the normal negative feedback
loop (pseudohypoparathyroidism).
The classic imaging features of advanced primary hyperparathyroidism are
less frequently seen today. Generalized osteopenia is the most common imaging
finding in primary hyperparathyroidism. Only very rarely encountered in primary
hyperparathyroidism, diffuse or localized osteosclerosis is a more common
finding in secondary hyperparathyroidism. When involving the spine, sclerosis
can produce a striped appearance, the so-called “rugger jersey” spine.
Subperiosteal bone resorption is a common finding of advanced
hyperparathyroidism, most often seen involving the hands and the feet. Although
classically most pronounced at the radial aspects of the second and third
middle phalanges, subperiosteal resorption can also be seen involving the
medial aspects of the metaphyses of the long bones as well as the ribs and
lamina dura of the teeth. Other areas of bone resorption are seen at sites of high
bone surface area and include subchondral locations, often best appreciated at
the sacroiliac, acromioclavicular, sternoclavicular, and temporomandibular
joints, the symphysis pubis, and the patella.
Brown tumors, also known as osteoclastomas,
are eccentrically located and often expansile lesions resulting from amassing
osteoclasts and fibrous tissue. Chondrocalcinosis is a nonspecific finding that
has a higher prevalence in primary rather than secondary primary
hyperparathyroidism. Although also having a higher prevalence in primary primary
hyperparathyroidism, brown tumors are more frequently encountered in the
setting of secondary primary hyperparathyroidism due to the greater prevalence
of this condition. Soft-tissue calcification and periostitis are among the
radiographic findings more commonly seen in secondary hyperparathyroidism.
References:
1.
Douglas K.
McDonald et al : Primary hyperparathyroidism due to parathyroid adenoma.
Radiographics ; 2005 :25:3:829-834
2. D murphy et al : Musculoskeletal
manifestations of chronic renal insufficiency. Radiographics : 1993 13:2
357-379
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