Osteomesopyknosis is a rare sclerosing bone disorder of autosomal dominant inheritance. We report a first case of osteomesopyknosis in Korea. A 16-year old girl complained of diffuse back pain for 1 year. We performed physical examination, biochemical investigations and imaging studies. A radiograph of spine revealed rugger-jersey vertebra and sandwich vertebra. Bone specific alkaline phosphatase, osteocalcin and C-terminal telopeptides of type I collagen were normal. Only an axial skeleton involvement was shown on the whole body bone scan. This patient was diagnosed to have osteomesopyknosis. Osteomesopyknosis is characterized by normal level of bone turnover marker and an axial bone involvement. Osteomesopyknosis can be occurred in Korea and needs to be considered when patients, especially young patients, suffer from back pain and have only axial osteosclerosis.
Osteomesopyknosis is rare and a benign osteosclerosis of autosomal dominant inheritance. It was first described by Simon et al.[
A 16-year old girl visited to orthopedic clinic at Daegu Fatima Hospital due to a history of diffuse back pain for 1 year. Back pain was aggravated when she kept sitting or standing for a long time. Spine X-ray was taken which showed sclerotic change of spine endplate and pelvic bone. Rugger-jersey vertebra and sandwich vertebra was shown (
The patient's blood pressure was 120/90 mmHg and her heart rate was 88 beats/min. Her weight was 63 kg and height was 160.3 cm. The results of a physical examination were unremarkable. There was no tenderness, redness and heatness on her back. Back mobility was normal and kyphoscoliosis was not observed. She had a normal stature and no history of fractures. On laboratory examination, liver function and renal function was normal. 25-hydroxy-vitamin D (25-[OH]D) was 7.2 ng/mL (normal range 30.1 to 100.0 mg/mL). 1,25-(OH)D was 27.88 pg/mL (normal range 19.6 to 54.3 pg/mL). Ten point one mg/dL calcium (normal range 9.0 to 11.0 mg/dL), 3.7 mg/dL phosphate (normal range 2.3 to 4.7 mg/dL), 31.7 pg/mL intact parathyroid hormone (normal range 12 to 88 pg/mL) and 5 U/mL rheumatoid factor (normal range 0 to 14 U/mL) were checked. Thyroid stimulating hormone level was 0.484 µIU/mL (normal range 0.7 to 6.4 µIU/mL), but serum free T4 was normal.
In order to identify the cause of osteosclerosis, we checked born turnover markers. Bone specific ALP was 19.11 U/L (normal range 11.6 to 42.7 U/L), osteocalcin was 15.76 ng/mL (normal range 11.0 to 46.0 ng/mL) and C-terminal telopeptides of type I collagen was 0.265 ng/mL (normal range 0 to 1.008 ng/mL). All of these markers were within normal limit.
Assessment of the extent of bone involvement is an important clue to differentiate osteosclerosis. Skull X-ray did not show any abnormality (
There was no evidence of increased bone turnover marker and only an axial skeleton involvement was shown on the whole body bone scan. These findings were compatible with osteomesopyknosis. Her mother did not have osteosclerotic lesion in spine radiograph. She has no father, sister or brother. So we could not perform further radiologic investigation of her family.
Osteomesopyknosis is a very rare sclerosing bone disorder. Only a few cases were published, the prevalence and pathogenesis are not known. As far as we know, this is the first case in Korea.
The characteristic finding of osteomesopyknosis is osteosclerosis confined to axial skeleton such as spine, pelvis and proximal part of long bone.[
In the Paget's disease of bone characterized by an accelerated rate of bone remodeling, bone specific ALP is usually elevated and pagetic changes in bone can be seen skull, spine, pelvis, and long bones of the lower extremities.[
Osteomesopyknosis is known to have autosomal dominant inheritance, there are reported cases that did not show radiological changes in the parents of the patient.[
Osteosclerosis is an elevation in bone density and shown as an increased opacity on a radiography. There are many diseases that lead to bony sclerosis such as osteopetrosis, Paget disease and osteomalacia. Differential points are inheritance pattern, age at onset, commonly affected sites, combined abnormality and etc.[
In Asia, there are only three Japaness case reports.[
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