Albright's Syndrome

Definition

Definition of Albright's Syndrome
McCune-Albright syndrome, described in 1937 by Donovan James McCune and Fuller Albright, is a genetic disorder of bones, skin pigmentation and hormonal problems along with premature puberty.

People with McCune-Albright syndrome develop areas of abnormal scar-like (fibrous) tissue in their bones, a condition called polyostotic fibrous dysplasia. Polyostotic means the abnormal areas (lesions) may occur in many bones; often they are confined to one side of the body. Replacement of bone with fibrous tissue may lead to fractures, uneven growth, and deformity. When lesions occur in the bones of the skull and jaw it can result in uneven (asymmetric) growth of the face. Asymmetry may also occur in the long bones; uneven growth of leg bones may cause limping. Abnormal curvature of the spine (scoliosis) may also occur. Bone lesions may become cancerous, but this happens in fewer than 1 percent of people with McCune-Albright syndrome.

Symptoms

Symptoms of Albright's Syndrome
It is suspected when two of the three following features are present:

• (autonomous) endocrine hyperfunction such as precocious puberty
• Polyostotic fibrous dysplasia
• Unilateral Café-au-lait spots

Diagnosis

Diagnosis of Albright's Syndrome
PTH infusion (at present with commercially available synthetic 1-34 peptide) and measurement of urinary cAMP excretion.

Treatment

Treatment of Albright's Syndrome
Medical treatment for McCune-Albright syndrome (MAS) is only partially effective and transsphenoidal surgery remains difficult secondary to massive thickening of the skull base. Radiotherapy is contraindicated because of the possibility of sarcomatous transformation. Their puberty does not generally respond to gonadotropic-releasing hormone agonists, and short-acting aromatase inhibitors have had limited effectiveness. Bromocriptine, cabergoline, and octreotide or a combination of these has demonstrated inconsistent results; pegvisomant, a GH receptor antagonist, is a possibility, although it has not yet been used as a treatment for MAS with GH pathology.

Prognosis

Prognosis of Albright's Syndrome

• Apart from the small subgroup of patients that have increased perioperative mortality and those who develop malignancies, McCune-Albright syndrome is not associated with a significantly increased mortality risk.
• Deformities associated with polyostotic fibrous dysplasia result in variable degrees of morbidity, ranging from mild to very severe.
• Sudden cardiac death has been reported in a few severely affected patients.

Complications

Complications of Albright's Syndrome

• Complications of fractures include secondary osteomyelitis, compressive neuropathy, Volkmann's contractures, sympathetic algodystrophy, myositis, ligamentous ossifications and pseudoarthrosis.
• The most serious complication of polyostotic fibrous dysplasia is osteosarcoma, which most often follows irradiation to affected bones. It is very uncommon with an overall incidence rate of 1% in patients with polyostotic fibrous dysplasia. Most often, it involves the bones of the face and femur.
• Skull involvement may cause compression neuropathies of the optic nerve, vestibulocochlear nerve or the cranial nerves located at the base of the skull.
• A minority of patients have significant risk for perioperative sudden death. This is presumed to be secondary either to cardiomyopathy or to arrhythmia.
• Females may have a greater risk for breast cancer, probably due to their prolonged exposure to elevated oestrogen levels.
• Hypophosphataemic rickets may further worsen the bone disease associated with polyostotic fibrous dysplasia.