Polyostotic fibrous dysplasia with acromegaly

Acromegaly and McCune-Albright syndrome

BACKGROUND

McCune-Albright syndrome (MAS) includes the triad of poly/monostotic fibrous dysplasia, café-au-lait spots, and hyperfunctioning endocrinopathies. Acromegaly affects around 20% of MAS patients.

AIMS

The objective was to review all reported cases of acromegaly associated with MAS.

METHODS

All studies and case reports of acromegaly in patients with MAS were systematically sought in the world literature up to January 2013. We also included new data (from three unreported cases) and updated data on 23 previously reported patients from our two centers.

RESULTS

We reviewed the cases of 112 patients (65 males). Mean age at diagnosis of acromegaly was 24.4 years (range, 3-64). Among the 40 pediatric patients, 23 (57%) had precocious puberty. GH/IGF-1 excess was suggested by accelerated growth in 85% of pediatric cases. Acromegaly was almost always associated with skull base fibrous dysplasia. Modern imaging techniques (computed tomography or magnetic resonance imaging) revealed an adenoma in 54% of the patients (macroadenoma in more than two-thirds). Median GH levels and mean IGF-1 SD score at diagnosis were 57 μg/L (2.8 to 291 μg/L) and 8 (2.3 to 24), respectively. Hyperprolactinemia was present in 81% (mean, 149 μg/L; range, 21-600). Pituitary surgery, performed in 25 cases, very rarely cured the GH/IGF-1 excess. Somatostatin analogs improved GH/IGF-1 levels in most patients but achieved control of acromegaly in only 17 (30%) of 56 patients. Pegvisomant achieved normal IGF-1 levels in 10 of 13 cases.

CONCLUSION

Acromegaly, which is present in 20-30% of patients with MAS, raises particular diagnostic and therapeutic issues.

Polyostotic fibrous dysplasia with gigantism and huge pelvic tumor: a rare case of McCune-Albright syndrome

We report a rare case of polyostotic fibrous dysplasia on endocrine hyperfunction with elevated human growth hormone and normal serum level of prolactin. There were some differential points of gender, gigantism, endocrine function, and GNAS gene from McCune-Albright syndrome. Malignant transformation was suspected in the pelvic tumor from imaging because rapid growth of the tumor by imaging was observed; however, no malignant change occurred in this case.

Acromegaly with fibrous dysplasia: McCune-Albright Syndrome -- clinical studies in 3 cases and brief review of literature--

The McCune-Albright syndrome (MAS) is characterized by a triad of poly/monostotic fibrous dysplasia, café-au-lait macules and hyperfunctioning endocrinopathies including growth hormone (GH) excess. Polyostotic bone lesions and café-au-lait macules are common while monostotic bone lesions are rare. Similarly, acromegaly as a manifestation of endocrine hyperfunction with MAS is uncommon and in most of the instances somatotropinoma has not been documented. We report 3 patients, two of them had monostotic lesion, none had café-au-lait macules and all had GH secreting pituitary macroadenoma. All of them underwent transfrontal pituitary adenomectomy and had histopathological confirmation of GH secreting pituitary adenoma. A brief review of literature is also presented.

Fibrous Dysplasia of the Temporal Bone: Report of a Case and a Review of its Characteristics

Fibrous dysplasia is an uncommon benign disorder of unknown etiology. It represents a disturbance of normal bone development—specifically a defect in osteoblastic differentiation and maturation that originates in the mesenchymal precursor of the bone.

Because fibrous dysplasia shows a predilection for the facial and cranial bones, where it causes deformity and dysfunction, the disease is of particular interest to the otolaryngologist. In this paper, we report a case of fibrous dysplasia of the temporal bone, the first symptom of which was a mixed hearing loss. We discuss the characteristic features of this specific location of the disease, the differential diagnosis, and the treatment policy. We also address the issue of secondary sensorineural hearing loss.

A case of pituitary adenoma associated with McCune-Albright syndrome

A 11-year-old boy presented with right temporal hemianopsia and was evaluated of a possible pituitary adenoma. At the age of six, he underwent surgery for facial deformities due to fibrous dysplasia. On admission, he had acromegalic features, was 170 cm tall, weighing 66 kg. The left side of his face was slightly deformed, and a café-au-lait spot was found on his right face. Endocrinologic examination revealed elevated basal level of serum GH (103.6 ng/ml, normal < 3 ng/ml) and PRL (259.1 ng/ml, normal < 30 ng/ml). Other endocrine functions were normal. CT showed hyperostosis of the right frontal, occipital, sphenoidal and maxillary bones. Magnetic resonance imaging (MRI) revealed a pituitary macroadenoma with intraadenomatous cyst. On the basis of physical, endocrinologic and neuroradiologic examination, our diagnosis was pituitary adenoma with McCune-Albright syndrome. Surgery was performed by subfrontal approach. By light microscopy, the pituitary tumor represented a typical acidophilic adenoma. Immunoreactivity for GH and PRL were evident in most of the adenoma cells. Double immunostaining for GH and PRL demonstrated the co-existence of the two hormones in a few adenoma cells. However the majority of cells expressed only one hormone. After surgery the right temporal hemianopsia improved. Postsurgical endocrinologic examination revealed reduction in basal serum GH and PRL levels. Administration of bromocriptine decreased blood PRL levels but it had a limited action on GH hypersecretion.

Clinical implications of genetic defects in G proteins. The molecular basis of McCune-Albright syndrome and Albright hereditary osteodystrophy

Inactivating and activating mutations in the gene encoding G alpha s (GNAS1) are known to be the basis for 2 well-described contrasting clinical disorders, Albright hereditary osteodystrophy (AHO) and McCune-Albright syndrome (MAS). AHO is an autosomal dominant disorder due to germline mutations in GNAS1 that decrease expression or function of G alpha s protein. Loss of G alpha s function leads to tissue resistance to multiple hormones whose receptors couple to G alpha s. By contrast, MAS results from postzygotic somatic mutations in GNAS1 that lead to enhanced function of G alpha s protein. Acquisition of the activating mutation early in life leads to a more generalized distribution of the mosaicism and is associated with the classic clinical triad of polyostotic fibrous dysplasia, endocrine hyperfunction, and café au lait skin lesions described in MAS. Acquisition of a similar activating mutation in GNAS1 later in life presumably accounts for the restricted distribution of the gsp oncogene, and is associated with the development of isolated lesions (for example, fibrous dysplasia, pituitary or thyroid tumors) without other manifestations of MAS. Tissues that are affected by loss of G alpha s function in AHO are also affected by gain of G alpha s function in MAS, thus identifying specific tissues in which the second messenger cAMP plays a dominant role in cell growth, proliferation, or function. Further investigations of the functions of G alpha s and other members of the GTPase binding protein family will provide more insight into the pathogenesis and clinical manifestations of human disease.

Octreotide therapy of growth hormone excess in the McCune-Albright syndrome

We report a patient with the McCune-Albright syndrome and growth hormone excess. Biochemical evaluation demonstrated characteristic changes typical of acromegaly, and an unusual pattern of delayed somatotropin response to hGHRH40, not previously described in this syndrome. Therapeutic trial of low-dose octreotide successfully reversed his growth hormone excess, whereas bromocriptine failed to reduce growth hormone levels. Previous reports of acromegaly and McCune-Albright syndrome are reviewed, and the unique features of this case discussed.

Acromegaly, multinodular goiter and silent polyostotic fibrous dysplasia. A variant of the McCune-Albright syndrome

A 36-year-old woman is reported with a possible variant of the McCune-Albright syndrome. The triad was incomplete because of the absence of skin pigmentation and since the sexual precocity was not evident. The presence of a pituitary mass and the secretory dynamics of growth hormone and prolactin were suggestive of a mammosomatotroph cell adenoma. A toxic multinodular goiter was also associated, but unique was the spontaneous normalization of the thyroid function. Unusual was the silent evolution of the polyostotic fibrous dysplasia, which was only fortuitously discovered during magnetic resonance imaging of the pituitary region. Treatment of the acromegaly with the long-acting somatostatin analogue octreotide resulted in an important inhibition of the GH secretion and in a reduction of the volume of the pituitary adenoma.

Polyostotic fibrous dysplasia associated with extensive linear epidermal naevi

Albright's syndrome is characterized by the combination of polyostotic fibrous dysplasia, precocious puberty and café-au-lait spots. We describe a patient with polyostotic fibrous dysplasia who also had extensive linear epidermal naevi, an association that has not been previously described in the English literature.

Fibrous dysplasia of the skull with acromegaly and sarcomatous transformation. Two cases with a review of the literature

Two cases of fibrous dysplasia of the skull are reported. Both patients were young women with acromegaly and were treated with radiotherapy. Progressive pareses of cranial nerves, pain, and a malignant course of the disease were characteristic in both patients, and the diagnosis of osteogenous sarcoma proved in one of them by histological examination. The clinical picture of fibrous dysplasia of the skull and the role of radiotherapy with the risk of development of malignancy is discussed.