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McCune-Albright Syndrome Differential Diagnoses

  • Author: Gabriel I Uwaifo, MD; Chief Editor: George T Griffing, MD  more...
 
Updated: Jan 13, 2015
 
 

Diagnostic Considerations

Early recognition of McCune-Albright syndrome (MAS) is vital. The diagnostic possibility of MAS should be considered in all patients with recurrent fractures, particularly if the fractures occur in the setting of minimal trauma or without trauma. The common pitfall is to simply refer the patient for orthopedic procedures whenever a fracture occurs, without considering the underlying primary diagnosis. The physician should have a high index of suspicion for other endocrinopathies associated with the condition.

If multiple bony fractures and deformity predominate, MAS may be mistaken for a milder form of osteogenesis imperfecta. If precocious puberty predominates, the differential diagnosis becomes even wider and includes congenital adrenal hyperplasia. Vaginal bleeding in neonates and infants is one of the typical presentations of MAS. In this setting, rhabdomyosarcoma of the vaginal tract is an important differential. This typically appears as a “bunch of grapes” (hence the name sarcoma botryoides).

In a typical case, the diagnosis of MAS usually is not in doubt. However, in atypical cases, the combination of cutaneous pigmentation, bony lesions, and soft-tissue masses may suggest other conditions (eg, systemic mastocytosis and neurofibromatosis).

In addition to the conditions listed in the differential diagnosis, other problems to be considered include the following:

  • Central precocious puberty
  • Congenital adrenal hyperplasia
  • Exogenous estrogens, androgens, steroids, or thyroid hormone
  • Organic brain disease or tumors
  • Ovarian tumors
  • Ossifying fibromas of bone
  • Proteus syndrome
  • Russell-Silver syndrome
  • Stein-Leventhal syndrome
  • Thyrotoxicosis
  • Various congenital syndromes associated with hydrocephalus

Differential Diagnoses

 
 
Contributor Information and Disclosures
Author

Gabriel I Uwaifo, MD Associate Professor, Section of Endocrinology, Diabetes and Metabolism, Louisiana State University School of Medicine in New Orleans; Adjunct Professor, Joint Program on Diabetes, Endocrinology and Metabolism, Pennington Biomedical Research Center in Baton Rouge

Gabriel I Uwaifo, MD is a member of the following medical societies: American Association of Clinical Endocrinologists, American College of Physicians-American Society of Internal Medicine, American Diabetes Association, American Medical Association, American Society of Hypertension, Endocrine Society

Disclosure: Nothing to disclose.

Coauthor(s)

Nicholas J Sarlis, MD, PhD, FACP Vice President, Head of Medical Affairs, Incyte Corporation

Nicholas J Sarlis, MD, PhD, FACP is a member of the following medical societies: American Association for the Advancement of Science, American Association for Cancer Research, American Association of Clinical Endocrinologists, American College of Physicians, American Federation for Medical Research, American Head and Neck Society, American Medical Association, American Society for Radiation Oncology, American Thyroid Association, Endocrine Society, New York Academy of Sciences, Royal Society of Medicine, Association for Psychological Science, American College of Endocrinology, European Society for Medical Oncology, American Society of Clinical Oncology

Disclosure: Received salary from Incyte Corporation for employment; Received ownership interest from Sanofi-Aventis for previous employment; Received ownership interest/ stock & stock option (incl. rsu) holder from Incyte Corporation for employment.

Noah S Scheinfeld, JD, MD, FAAD Assistant Clinical Professor, Department of Dermatology, Weil Cornell Medical College; Consulting Staff, Department of Dermatology, St Luke's Roosevelt Hospital Center, Beth Israel Medical Center, New York Eye and Ear Infirmary; Assistant Attending Dermatologist, New York Presbyterian Hospital; Assistant Attending Dermatologist, Lenox Hill Hospital, North Shore-LIJ Health System; Private Practice

Noah S Scheinfeld, JD, MD, FAAD is a member of the following medical societies: American Academy of Dermatology

Disclosure: Serve(d) as a speaker or a member of a speakers bureau for: Abbvie<br/>Received income in an amount equal to or greater than $250 from: Optigenex<br/>Received salary from Optigenex for employment.

Chief Editor

George T Griffing, MD Professor Emeritus of Medicine, St Louis University School of Medicine

George T Griffing, MD is a member of the following medical societies: American Association for the Advancement of Science, International Society for Clinical Densitometry, Southern Society for Clinical Investigation, American College of Medical Practice Executives, American Association for Physician Leadership, American College of Physicians, American Diabetes Association, American Federation for Medical Research, American Heart Association, Central Society for Clinical and Translational Research, Endocrine Society

Disclosure: Nothing to disclose.

Acknowledgements

Bruce A Boston, MD Chief, Division of Pediatric Endocrinology, Director, Pediatric Endocrine Training Program, Doernbecher Children's Hospital; Professor, Department of Pediatrics, Division of Pediatric Endocrinology, Oregon Health and Science University School of Medicine

Bruce A Boston, MD is a member of the following medical societies: Alpha Omega Alpha, American Diabetes Association, Endocrine Society, and Pediatric Endocrine Society

Disclosure: Nothing to disclose.

Arthur B Chausmer, MD, PhD, FACP, FACE, FACN, CNS Professor of Medicine (Endocrinology, Adj), Johns Hopkins School of Medicine; Affiliate Research Professor, Bioinformatics and Computational Biology Program, School of Computational Sciences, George Mason University; Principal, C/A Informatics, LLC

Arthur B Chausmer, MD, PhD, FACP, FACE, FACN, CNS is a member of the following medical societies: American Association of Clinical Endocrinologists, American College of Endocrinology, American College of Nutrition, American College of Physicians, American College of Physicians-American Society of Internal Medicine, American Medical Informatics Association, American Society for Bone and Mineral Research, Endocrine Society, and International Society for Clinical Densitometry

Disclosure: Nothing to disclose.

George P Chrousos, MD, FAAP, MACP, MACE, FRCP(London) Professor and Chair, First Department of Pediatrics, Athens University Medical School, Aghia Sophia Children's Hospital, Greece; UNESCO Chair on Adolescent Health Care, University of Athens, Greece

George P Chrousos, MD, FAAP, MACP, MACE, FRCP(London) is a member of the following medical societies: American Academy of Pediatrics, American College of Endocrinology, American College of Physicians, American Pediatric Society, American Society for Clinical Investigation, Association of American Physicians, Endocrine Society, Pediatric Endocrine Society, and Society for Pediatric Research

Disclosure: Nothing to disclose.

Marcie K Drury Brown, MD Fellow in Pediatric Endocrinology, Department of Pediatrics, Oregon Health and Science University

Marcie K Drury Brown, MD is a member of the following medical societies: American Academy of Pediatrics, American Medical Association, and Oregon Medical Association

Disclosure: Nothing to disclose.

Dirk M Elston, MD Director, Ackerman Academy of Dermatopathology, New York

Dirk M Elston, MD is a member of the following medical societies: American Academy of Dermatology

Disclosure: Nothing to disclose.

Sherry L Franklin, MD, FAAP Medical Director, Pediatric Endocrinology of San Diego Medical Group, Inc

Sherry L Franklin is a member of the following medical societies: American Academy of Pediatrics, American Diabetes Association, American Medical Association, Pediatric Endocrine Society, and The Endocrine Society.

Disclosure: Nothing to disclose.

Stephen Kemp, MD, PhD Professor, Department of Pediatrics, Section of Pediatric Endocrinology, University of Arkansas for Medical Sciences College of Medicine, Arkansas Children's Hospital

Stephen Kemp, MD, PhD is a member of the following medical societies: American Academy of Pediatrics, American Association of Clinical Endocrinologists, American Pediatric Society, Endocrine Society, Phi Beta Kappa, Southern Medical Association, and Southern Society for Pediatric Research

Disclosure: Nothing to disclose.

Van Perry, MD Assistant Professor, Department of Medicine, Division of Dermatology, University of Texas School of Medicine at San Antonio

Van Perry, MD is a member of the following medical societies: American Academy of Dermatology and American Society for Laser Medicine and Surgery

Disclosure: Nothing to disclose.

Arlan L Rosenbloom, MD Adjunct Distinguished Service Professor Emeritus of Pediatrics, University of Florida College of Medicine; Fellow of the American Academy of Pediatrics; Fellow of the American College of Epidemiology

Arlan L Rosenbloom, MD is a member of the following medical societies: American Academy of Pediatrics, American College of Epidemiology, American Pediatric Society, Endocrine Society, Florida Pediatric Society, Pediatric Endocrine Society, and Society for Pediatric Research

Disclosure: Nothing to disclose.

Eleanor E Sahn, MD Director, Division of Pediatric Dermatology, Associate Professor, Departments of Dermatology and Pediatrics, Medical University of South Carolina

Eleanor E Sahn, MD is a member of the following medical societies: Alpha Omega Alpha, American Academy of Dermatology, and Southern Medical Association

Disclosure: Nothing to disclose.

Francisco Talavera, PharmD, PhD Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference

Disclosure: Medscape Salary Employment

Richard P Vinson, MD Assistant Clinical Professor, Department of Dermatology, Texas Tech University Health Sciences Center, Paul L Foster School of Medicine; Consulting Staff, Mountain View Dermatology, PA

Richard P Vinson, MD is a member of the following medical societies: American Academy of Dermatology, Association of Military Dermatologists, Texas Dermatological Society, and Texas Medical Association

Disclosure: Nothing to disclose.

D Stanton Whittaker Jr, MD Consulting Staff, Boone Dermatology Clinic

Disclosure: Nothing to disclose.

Mary L Windle, PharmD Adjunct Associate Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference

Disclosure: Nothing to disclose.

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Base of the skull computed tomography scan showing extensive fibrous dysplasia in McCune-Albright syndrome. Note the asymmetrical affectation, with near-total obliteration of various neural foramina at the base of the skull. This degree of fibrous dysplasia can result in multiple cranial nerve compression neuropathies, of which blindness and deafness (from involvement of cranial nerves II and VIII) are among the most disabling.
Café au lait spot. This is a fairly large, irregular-edged ("coast-of-Maine" variety) lesion. It presents as a brownish, otherwise-asymptomatic macule/patch. The degree of pigmentation is fairly uniform.
Fibrous dysplasia of a long bone characterized by focal bony expansion, patchy areas of sclerosis, and bony cyst formation in McCune-Albright syndrome.
Plain skull radiograph in a typical McCune-Albright syndrome case shows marked macrocrania, frontal bossing, and markedly thickened bony table in patchy areas, particularly at base of skull and occiput. Skull also shows hair-on-end appearance, which needs to be differentiated from similar radiologic appearances in Paget disease or poorly controlled hemoglobinopathy (eg, beta-thalassemia, sickle cell disease).
Large café-au-lait patches around shoulder in child with McCune-Albright syndrome.
Lucency characteristic of polyostotic fibrous dysplasia in patient with McCune-Albright syndrome.
Café-au-lait pigmentation in case of McCune-Albright syndrome. Lesion does not cross midline, which is typical of pigmented lesions in this syndrome.
Adrenal hyperplasia with nodular elements in adrenal gland isolated from infant with infantile Cushing syndrome in the context of McCune-Albright syndrome. DNA isolated from nodular tissue was determined to have activating Gs alpha mutation (GNAS1), whereas DNA isolated from surrounding tissue did not contain this mutation.
The G protein cycle begins with ligand binding to a 7-transmembrane domain G protein-coupled receptor (GPCR). Binding of the cognate ligand forms a ligand-receptor complex, which then stimulates an exchange of guanosine triphosphate (GTP) for guanosine diphosphate (GDP) on the alpha subunit of the stimulatory G protein (Gs alpha). This activates the alpha subunit, which subsequently stimulates adenylyl cyclase (AC) to increase production of cyclic adenosine monophosphate (cAMP). The alpha subunit contains intrinsic guanosine triphosphatase (GTPase) activity, which cleaves a phosphate group from GTP, converting it to GDP, and thus inactivates the alpha subunit. The inactivated alpha subunit is now ready to be reactivated by ligand-receptor binding, so that the next cycle of signal transduction can occur.
Mutations in McCune-Albright syndrome inactivate intrinsic guanosine triphosphatase (GTPase) activity, thus preventing inactivation of the "turned-on" Gs alpha subunit. Once activated, the mutated Gs alpha subunit is able to continuously stimulate adenylyl cyclase, even in absence of ligand binding to its cognate GPCR receptor. The result is elevation of intracellular cyclic adenosine monophosphate (cAMP) and continual stimulation of downstream cAMP signaling cascades.
 
 
 
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