RISKING THE creation of yet another “pseudo-” for the bone field (e.g., pseudofracture, pseudohyperparathyroidism, pseudo- and pseudopseudohypoparathyroidism, pseudohypohyperparathyroidism, pseudohypophosphatasia, pseudoprecocious puberty, pseudotumor cerebri, pseudotumor in myositis ossificans progressiva, pseudovitamin D deficiency rickets), we illustrate skin findings in an elderly patient with McCune-Albright syndrome (MAS) that resemble café-au-lait spots but actually are illusions caused by vitiligo.
Café-au-lait spots, fibrous dysplasia of bone, and endocrine gland hyperactivity are the principal features of McCune-Albright syndrome (MAS). Café-au-lait spots appear at, or soon after, birth. We illustrate “café-au-lait spots” acquired during middle age in a patient with MAS that are an illusion caused by vitiligo. This 64-year-old woman is the oldest patient reported with this disorder.
This 64-year-old white woman was diagnosed in infancy with MAS. At birth, one large café-au-lait spot involved her right buttock and posterior thigh. Soon after birth, she suffered limb fractures caused by polyostotic fibrous dysplasia (POFD). There was no pseudoprecocious puberty, but thyrotoxicosis was treated with131I at the age of 20 years. Both knees and one hip were replaced successfully during her late 50s. She was referred because of hearing loss and increasingly frequent and intense headaches for 6 months.
Physical examination showed mild facial and skull asymmetry, 90% hearing loss in the left ear, and the aforementioned café-au-lait spot (Fig. 1A). Additionally, there were similar large, rough-border, seemingly hyperpigmented areas laterally on both forearms (Fig. 1B). Screening biochemical and hormone function studies were unremarkable. Review of her radiographs showed patchy skeletal abnormalities characteristic of POFD (Fig. 2A). Computed tomography (CT) of her head revealed no significant parenchymal abnormalities, but osseous changes of POFD involved the left temporal, maxillary, and sphenoid bones and both parietal bones (Fig. 2B).
Her headaches stopped with carbamazepine treatment. Further history revealed that hypopigmentation of the hands and forearms began at the age of 51 years and extended over a 1-year period. A dermatologist diagnosed vitiligo.
Café-au-lait spots are well-circumscribed, uniformly pale-brown macules with serrated or irregular margins that appear at or soon after birth but may fade with age.(1) They are relatively small with smooth boarders in neurofibromatosis and large with rough borders in MAS (“coast of California” vs. “coast of Maine,” respectively). In MAS, café-au-lait macules presumably reflect melanocytes manifesting postzygotic mosaicism for an activating mutation in the GNAS1 gene which encodes the α-subunit of the G protein (Gsα) that stimulates adenylyl cyclase.(2) Vitiligo is a specific, often heritable, acquired disorder characterized by well-circumscribed, milky-white cutaneous macules devoid of identifiable melanocytes.(1) The cause is poorly understood despite its incidence of 1-2% in the population.(1) We found no report of vitiligo in MAS, but few adults are described in the medical literature and none > 60 years of age.