INFORMATION

Patient 64 years of age, with no known drug allergies and a past history of fibromialgia treated with tramadol, paracetamol and cyclobenzaprine. He was referred after having noticed an increase in the volume of his jaw over the last year, with deterioration of his mandibular prognathism.

He was also referred for bilateral hypoacusis (hearing loss) for 2-3 years.

Examination: mandibular prognathism, bilateral hypoacusis, positive fibrositic points. No other muscle-skeletal abnormalities.

Investigations: Haematology and biochemistry normal, normal calcium and phosphate, ESR 19, PCR 0.2, HLA non-specific, ANA, antiDNA and rheumatoid factor negative, normal coagulation studies, calciuria normal, PTH 104 pg/ml (10-80), vitamin D3 70.7 ng/ml (11-70).

Xray of jaw: normal Bone densitometry: Intense radio-uptake of the mandibular bone corresponding with Paget’s disease. The patient received treatment with zolendronic acid 5 mg/100 ml IV.

Comment: The mandible is not frequently affected in Paget’s disease. In bone densitometry an image described as "Lincoln’s beard" can be seen

Paget’s disease (PD) is a bone disorder characterized by acceleration of the "turnover" of bone, which produces excessive reabsorption and bone formation. As a consequence the bone is expanded, weakened, and deformed and the skin covering it is able to transmit greater heat to the touch. The incidence of the disease is difficult to estimate because most cases are asymptomatic. Nevertheless, it seems that it increases with age and men and women are similarly affected. The etiology of PD is unknown; studies suggest different etiological factors such as genetic, viral infection and geographical distribution, as this illness is more frequent in populations with high concentrations of people of anglo-saxon origin.

The majority of patients are asymptomatic and the disease is discovered incidentally through routine blood tests that show elevated alkaline phosphotase (ALP) or through a plain x-ray for another reason. The most prominent clinical manifestations of PD are bone pain and deformity. Any part of the skeleton can be affected but the areas more frequently involved are: pelvis, spine, skull and long bones (proximal and distal).

Other manifestations of PD can be:

• Neurological: When the skull is affected the 8th cranial nerve can be compressed producing deafness. Other cranial nerves affected can be the 2nd, 5th and 7th. Obstructive hydrocephalus, basilar invagination and ischemic myelitis are less frequent.
• Cardiac: Cardiac insufficiency, aortic stenosis and alterations of the conduction system can be found.
• Alterations in phospho-calcium metabolism: hypercalcaemia due to primary or secondary hyperparathyroidism.

The most frequent complications are traumatic or pathological fractures of the affected bone and bony tumors. The most frequent tumour is osteosarcoma although other types of tumors can be seen as well, such as the osteoclastoma, above all when the skull and facial bones are affected. For the diagnosis of PD markers of reabsorption (urinary excretion of hydroxyproline) and of bone formation (alkaline phosphotase) are used. The most utilized marker is ALP.

It can be normal in subjects with monostotic disease. The plain x-ray can show signs such as circumscribed osteoporosis, lytic changes with expansion, and increase in size of the bones and patterns of trabecular bone coarse in appearance. Bone densitometry is the most sensitive test to identify pagetic bones. Due to their high metabolic rate focal lesions appear with marked increase in uptake (hot spots).

Treatment is indicated in symptomatic patients: those with bone pain, nerve compression, headache due to affected skull, hypercalcemia. The need for treatment in asymptomatic patients is less clear.

The medications utilized for patients with PD are the biphosphonates and calcitonin

Authors:

Erardo Meriño Ibarra
Evangelina Palero Díaz
Berta Magallares López
Cilia Peralta Ginés
Concepción Delgado Beltrán

Servivio de Reumatología
Hospital Clínico Universitario “Lozano Blesa” Zaragoza

Translation: Kelly Watt