Post on 19-Dec-2015
description
MC CUNE –ALBRIGHT SYNDROMEpolyostotic fibrous dysplasia
Association of polyostotic fibrous dysplasia, precocious puberty, café-au-lait spots and other endocrinopathies due to hyperactivity of various endocrine glands.
ETIOLOGY Post zygotic mutation ----GS alpha gene
G protein -present in many cells, -involved in endocrine cell growth
and secretion - mutation –uncontrolled cell
function and increased harmonal secretion.
CLINICAL FEATURES Café-au-lait spots : (coffee with milk) increased amounts of melanin in basal
cells of epidermis . generally seen in lower lumbar spine,
sacrum, buttocks,upper back,neck,shoulder, lips, oral mucosa.
well defined unilateral macules –coast line of maine.
Respect midline.
Café-au-lait skin pigmentation. A) "coast of Maine" borders, and the tendency for the lesions to respect the midline
B) Typical lesions that are often found on the nape of the neck and the buttocks are shown (arrows).
Polyostotic fibrous dysplasia:-- More then 75% of the skeleton---
McCune Albright syndrome. (when few bones are involved--- JAFFE- LICHTENSTEIN SYNDROME.)
The fibrous growth in bones--- bony deformities and fractures.
facial assymetry of skull and jaw bones.
HOCKEY STICK DEFORMITY– leg length discripency due to the involvment of upper portion of femer.
ENDOCRINOPATHIES Mutation in g protein cause– uncontrolled
harmonal secretions in various endocrine glands.
Precocious puberty:-- In women ovarian cysts--- excess oestrogen
production causing 1.early menstrual bleeding –2 years
2.early development of breasts 3. irregular menstrual bleeding. In men early development of testis and pubic
hair
Thyroid gland:-- adenoma and goiter – causing
hyperthyroidism. Moderately elevated basal metabolic rate
Pituitary gland:-- somatotroph adenomas cause increased
growth harmone secretion causing acromegaly.
Adrenal gland:-- bilateral non pigmented adrenocortical
hyperplasia causes cushings syndrome.
ORAL MANIFESTATIONS Enlarged , expanded and distorted jaws. Obliteration of maxillary sinus Oral pigmentation on the lips and buccal
mucosa. premature eruption of teeth.
RADIOGRAPHIC FINDINGS Roentgenographic examination lesion may be radiolucent , radiopaque or mixed. Radiopacity common in maxilla. Radiolucent area common in mandible and long
bones. Ground glass appearance:-- due to numerous ,
abnormal irregularly arranged bony trabaculae. Expansion of bone with thinned outer cortex
–classic feature. lion face (leontiasis ossea) Bone scanning:-: Asymptomatic sites of fibrous
dysplasia detection.
Reconstructed three-dimensional CT image shows lion face appearance due to asymmetrical involvement and enlargement of the bones of the face and the skull.
LABORATORY DIAGNOSIS Precocious puberty : gonadotrophin
independent elevation of estrogen levels elevated liver enzymes or
hyperbilirubinemia. Due to mutation in G protien of hepatocytes
hypophosphatemia may result from increased urinary phosphate excretion.
Elevated thyroxine levels Serum growth hormone (GH) and
insulinlike growth factor-1 (IGF-1) levels elevated.
MALIGNANCIES ASSOCIATED WITH ALBRIGHT SYNDROME OSTEOSARCO MC CUNE ALBRIGHT
SYNDROME(most common) CHONDROSARCO MC CUNE ALBRIGHT
SYNDROME FIBROSARCO MC CUNE ALBRIGHT SYNDROME LIPOSARCO MC CUNE ALBRIGHT SYNDROME THYROID MALIGNANCIES.
HISTOLOGICAL FINDINGS Histology:-- areas of fibrous metaplasia, Lesions typically expand concentrically from
the medullary cavity outward not capsulated Irregular trabacular pattern resembling
CHINESE LETTER PATTERN
DIFFERENTIAL DIAGNOSIS Gigantism and Acromegaly
Glucocorticoid Therapy and Cushing SyndromeHyperthyroidismHypophosphatemic RicketsNeurofibromatosis
TREATMENT Only symptomatic with multi disciplinary approach Bone treatments
Surgical bone grafting Ovary surgery
Surgical ovary cyst removal Estrogen inhibitors
Testolactone (blocks estrogen synthesis) Thyroid-inhibiting medications --Propylthiouracil. Treatments for phosphorus problems(low levels of phosphorus in
the blood due to excessive losses of phosphate in the urine. This may cause bone weakening and the condition called rickets ) --Oral phosphates Vitamin D
growth harmone:-Therapy has included surgical removal of the area of the pituitary which is secreting the hormone, and the use of new, synthetic analogs of the hormone somatostatin, which suppress growth hormone secretion.