leontiasis ossea

meg·a·ceph·a·ly

(meg'ă-sef'ă-lē),

A condition, either congenital or acquired, in which the head is abnormally large; usually applied to an adult cranium with a capacity of over 1450 mL.

Synonym(s): leontiasis ossea, macrocephaly, macrocephalia, megacephalia, megalocephaly, megalocephalia, Virchow disease

[mega- + G. kephalē, head]

McCune-Albright syndrome

An autosomal dominant condition (OMIM:174800) due to altered regulation of cAMP, endocrinopathy (e.g., hyperthyroidism) and hypophosphatemia.

Clinical findings
Precocious puberty, polyostotic (cystic fibrous dysplasia) spontaneous fractures at young age, café-au-lait spots on skin, ovarian cysts.
 
Lab
Cyclical 4–6-week fluctuations of plasma oestrogen; afflicted young girls have decreased gonadotropins, decreased response to LH-RH; increased testosterone, increased alkaline phosphatase.
 
Molecular pathology
Defects in GNAS, which encodes a G protein that modulates various membrane signalling cascasdes, cause McCune-Albright syndrome.

Management
Aromatase inhibitor testolactone.

leontiasis ossea

Enlargement and distortion of facial bones, giving one the appearance of a lion. It can occur as a complication of hyperparathyroidism, Paget's disease, uremia, and other conditions.

See also: leontiasis