Incidental detection of lumbar Paget's disease by bone densitometry.

Incidental detection of lumbar Paget's disease by bone densitometry SIR, Bone densitometry of the hip and lumbar spine using dual-energy X-ray absorptiometry (DXA) is used to diagnose osteoporosis. We report three patients who were referred for bone densitometry, in whom a diagnosis of Paget's disease was made after the investigation of significantly increased bone mineral density (BMD) of a single vertebral body. BMD measurements were performed using a Lunar DPX alpha scanner and the results were expressed according to the manufacturer's reference range. Patient 1 was a 54-yr-old woman who had taken oestrogen replacement therapy for 3 yr after a hysterectomy and bilateral oophorectomy 14 yr previously, and was referred for bone densitometry. There was a 1-yr history of low back pain. Investigations including a liver biopsy 3 months previously had failed to identify the cause of mildly impaired liver function tests. The bone isoenzyme of alkaline phosphatase was not increased. The BMD of vertebrae L2–4 was 1.478 gucm 2 (Table 1). The BMD of L2 was more than 40% higher than that of the other individual lumbar vertebrae. Lumbar spine X-rays and an isotope bone scan revealed Paget's disease affecting L2. Patient 2 was a 72-yr-old man with an 18-yr history of rheumatoid arthritis who had been taking prednisolone 5 mg daily for 2 yr. He was referred for bone densito-metry. He denied low back pain. The BMD of L2–4 was 1.631 gucm 2 (Table 1). The BMD of vertebra L2 was more than 20% higher than that of the other individual lumbar vertebrae. Lumbar spine X-ray revealed sclerosis and expansion of the vertebral body of L2 due to Paget's disease. Alkaline phosphatase was 106 IUul (normal range 40–120). Paget's disease had remained asymptomatic for 3 yr. Patient 3 was a 66-yr-old woman who was referred for bone densitometry after an episode of mid-thoracic pain. She had been taking Premarin (conjugated oestro-gens) 0.625 mg daily after a hysterectomy and bilateral oophorectomy 13 yr previously. There was no history of low back or leg pain, and thoracic spine X-rays revealed minor thoracic spondylosis. The BMD of vertebrae L2–4 was 0.952 gucm 2 , and that of L1 was more than 50% greater than the BMD of the other individual lumbar vertebrae (Table 1). Lumbar spine X-rays revealed uniform sclerosis of the L1 vertebral body without significant expansion, and the L4 vertebral body was expanded with an increased trabecular pattern. An …