By Gary M. White, MD

McCune-Albright syndrome (MAS) is characterized by multiple café au lait macules, polyostotic fibrous dysplasia and precocious puberty.


The café au lait patches of MAS are congenital or have their onset in the first two years of life. They tend to be large, few in number, ipsilateral to the bony defects, and with a jagged margin like the coast of Maine. It appears that they often follow two patterns, either they follow Blaschko's lines, or they are reminiscent of a flag-like rectangular pattern as found in human chimeras. The CALMs of neurofibromatosis tend to be round or oval, distributed randomly, have smooth borders, a diameter < 10 cm, and never follow Blaschko's lines. In contrast, CALMs of MAS often are bizarre in shape, may cover large areas, are jagged or irregular, and respect the midline.

Pigmented macules on the lips may occur [JAMA Derm 2014;150;760].


Systemic disorders include growth hormone-secreting and prolactin-secreting pituitary adenomas, autonomous adrenal hypercortisolism, primary hyperthyroidism, and phosphaturic osteomalacia.

Precocious puberty in girls may manifest itself as vaginal bleeding or spotting, accompanied by the development of breast tissue, usually without the development of pubic hair. In boys, it can be bilateral (or unilateral) testicular enlargement with penile enlargement, scrotal rugae, body odor, pubic and axillary hair, and precocious sexual behavior.


A multidisciplinary approach is necessary with the cutaneous changes of least importance.


Lip pigmentation in MAS JAMA Dermatol. 2014 Jul; 150(7): 760–763

A typical lesion on the face, chest, and arm of a 5-year-old girl with McCune-Albright syndrome which demonstrates jagged "coast of Maine" borders, and the tendency for the lesions to both respect the midline. Orphanet J Rare Dis. 2008; 3: 12.




Homepage | FAQs | Use of Images | Contact Dr. White

It is not the intention of to provide specific medical advice, diagnosis or treatment. only intends to provide users with information regarding various medical conditions for educational purposes and will not provide specific medical advice. Information on is not intended as a substitute for seeking medical treatment and you should always seek the advice of a qualified healthcare provider for diagnosis and for answers to your individual questions. Information contained on should never cause you to disregard professional medical advice or delay seeking treatment. If you live in the United States and believe you are having a medical emergency call 911 immediately.