A retrospective clinico-pathologic analysis of cemento-osseous dysplasia in a South African patient population

Background

Cemento-osseous dysplasia (COD) is a fibro-osseous jaw bone lesion. The affected bone in COD progressively becomes sclerotic, poorly vascularized and susceptible to secondary osteomyelitis.

Objective

To provide a clinico-pathologic appraisal of COD in a South African patient population.

Methods

Archived records of 133 patients diagnosed with COD were reviewed for patient demographics, COD location, COD type, osteomyelitis or simple bone cyst secondary to COD.

Results

The mean age was 53.4 ± 13.5 years with a 94.7% female predilection. COD mainly affected the mandible (57.1%), followed by involvement of both jaws (38.3%) and maxilla (4.5%). Florid COD was the most prevalent (69.9%), followed by focal COD (18%) and periapical COD (12%). Florid COD showed a clear trend of increasing with age, peaking in the sixth decade and decreasing thereafter. Osteomyelitis and simple bone cyst presented as complications of COD in 74.4% and 5.3% of cases respectively, while 21.8% of all cases of jaw osteomyelitis during the study period were secondary to COD.

Conclusion

A higher frequency of jaw osteomyelitis secondary to COD was found compared to previous studies. No significant association was shown between any of the COD types and secondary osteomyelitis.

Dental Manifestations of Pediatric Bone Disorders

PURPOSE OF REVIEW

Several bone disorders affecting the skeleton often are manifest in the maxillofacial region. This review presents the most common bone disorders in children and their dental-oral manifestations: fibrous dysplasia, Paget's disease, osteogenesis imperfecta, renal osteodystrophy, hypophosphatasia, and osteoporosis. The specific intraoral characteristics will reviewed in detail.

RECENT FINDINGS

Recent studies confirmed the close relationship between the mandible and the maxilla with the most prevalent systemic bone disorders in children. This review will help practitioners to integrate the oral health into the systemic health and improve the multidisciplinary approach of pediatric patients between medicine and dentistry.

La dysplasie fibreuse: état des lieux

La dysplasie fibreuse des os est une affection osseuse bénigne congénitale mais non héréditaire, où l'os normal est remplacé par un tissu fibreux renfermant une ostéogenèse immature. Elle est due à une mutation du gène GNAS 1sur le chromosome 20q13, une mutation activatrice de la sous-unité α de la protéine G. C'est une pathologie qui est le plus souvent silencieuse, de découverte fortuite sur une radiographie standard ou révélée par une douleur osseuse ou une fracture pathologique. L'imagerie et l'histologie, quand elle est nécessaire, permettent d’établir le diagnostic. Bien qu'il ne s'agisse pas d'une tumeur, elle est souvent classée dans la catégorie des tumeurs osseuses bénignes pour des raisons de diagnostic différentiel radiographique et anatomopathologique. Elle peut être monostotique ou polyostotique. L'approche thérapeutique est essentiellement symptomatique. Quelques publications récentes ont suggéré l'intérêt majeur d'un bisphosphonate, en particulier le pamidronate, qui diminuerait les douleurs et stimulerait une reminéralisation progressive des zones ostéolytiques chez les patients traités. D'autres traitements tels que la thérapie ciblée sont en cours d’évaluation.

Rapid biochemical response to denosumab in fibrous dysplasia of bone: report of two cases

We report on the clinical and biochemical outcomes in two adult patients with active polyostotic fibrous dysplasia (FD) treated with the RANK-L inhibitor, denosumab, following unsatisfactory responses to prior long-term bisphosphonate therapy. A 44-year-old female (case 1) who had received a cumulative dose of 20 mg zoledronic acid over 2.5 years and a 48-year-old male (case 2) who had received a cumulative dose of 45 mg zoledronic acid over 8 years both experienced minimal reductions in pain scores and markers of bone turnover. Following initiation of denosumab 60 mg sc, changes in bone pain, bone turnover [assessed by serum amino-terminal propeptide of type I collagen (PINP) and urinary deoxypyridinoline] were monitored over a period of 20 and 8 months, respectively. Following administration of denosumab, both patients demonstrated a rapid and pronounced biochemical response: Within 4-7 weeks, bone turnover markers fell to levels within the respective reference range, and one patient reported a reduction in pain. Treatment with denosumab was well tolerated. However, transient asymptomatic hypocalcaemia and/or hypophosphatemia associated with a transient two to threefold increase in serum PTH levels was observed in both patients. Dosing intervals for denosumab varied significantly between the two patients, depending on disease activity at baseline. Denosumab appears to be effective in reducing bone turnover in adult patients with active FD. However, caution should be exercised, and patients should be monitored carefully as significant fluctuations in biochemical and hormonal indices can occur.

Surgery versus watchful waiting in patients with craniofacial fibrous dysplasia--a meta-analysis

Background

Fibrous dysplasia (FD) is a benign bone tumor which most commonly involves the craniofacial skeleton. The most devastating consequence of craniofacial FD (CFD) is loss of vision due to optic nerve compression (ONC). Radiological evidence of ONC is common, however the management of this condition is not well established. Our objective was to compare the long-term outcome of patients with optic nerve compression (ONC) due to craniofacial fibrous dysplasia (CFD) who either underwent surgery or were managed expectantly.

Methodology/Principal Findings

We performed a meta-analysis of 27 studies along with analysis of the records of a cohort of patients enrolled in National Institutes of Health (NIH) protocol 98-D-0145, entitled Screening and Natural History of Fibrous Dysplasia, with a diagnosis of CFD. The study group consisted of 241 patients; 122 were enrolled in the NIH study and 119 were extracted from cases published in the literature. The median follow-up period was 54 months (range, 6–228 months). A total of 368 optic nerves were investigated. All clinically impaired optic nerves (n = 86, 23.3%) underwent therapeutic decompression. Of the 282 clinically intact nerves, 41 (15%) were surgically decompressed and 241 (85%) were followed expectantly. Improvement in visual function was reported in fifty-eight (67.4%) of the clinically impaired nerves after surgery. In the intact nerves group, long-term stable vision was achieved in 31/45 (75.6%) of the operated nerves, compared to 229/241 (95.1%) of the non-operated ones (p = 0.0003). Surgery in asymptomatic patients was associated with visual deterioration (RR 4.89; 95% CI 2.26–10.59).

Conclusions

Most patients with CFD will remain asymptomatic during long-term follow-up. Expectant management is recommended in asymptomatic patients even in the presence of radiological evidence of ONC.

Surgery improves vision and cosmetic appearance of an adult patient with fibrous dysplasia of the frontal bone

A 31-year-old woman with fibrous dysplasia (FD) of the left forehead was reported. Visual acuity impairment and diplopia were slowly progressive for 6 months associated with marked protrusion of her left forehead. Removal of left forehead lesion including the orbital ridge and total decompression of the optic canal and superior orbital fissure improved these visual symptoms dramatically. Reconstructive cranioplasty using artificial bone made by hydroxyapatite (Apaceram) was very satisfactory in cosmetic appearance. Surgical indication and neuroradiological findings of cranial FD are discussed as well as a review of the literatures.

[Fibrous dysplasia of bone]

Fibrous dysplasia of bone is a congenital non hereditary benign bone disease, where normal bone is replaced by a fibrous-like tissue with immature osteogenesis. Prevalence is difficult to estimate, due to frequent asymptomatic lesions. Bone lesions are mono- or polyostotic and may be associated with bone pain and fragility, leading to fractures. In some patients or bone sites, they are hypertrophic, responsible for neurological complications. Imaging and, when necessary, histology are the cornerstones of the diagnosis. A common molecular defect, i.e. activating mutations of the GNAS gene, encoding the a subunit of the Gs protein in target cells, is responsible for bone cell alterations as well as for the involvement of other cells/tissues bearing the same molecular defect (melanocytes, endocrine cells). These mutations affect only somatic cells and are therefore not hereditary: antenatal diagnosis is not appropriate for this disease and genetic counselling is not very useful, except for reassuring the patients. The conventional therapeutic approach is essentially symptomatic (pain killers) and orthopaedic (prevention and treatment of bone complications). Recent publications have focused attention on pamidronate, which rapidly relieves bone pain in most patients, and progressively increases bone mineralization in osteolytic areas in about half of the patients. Tubular phosphate wasting is common and should be treated with phosphate supplement and calcitriol. The prognosis should improve with therapeutic advances, but this remains to be properly evaluated.

Onset, progression, and plateau of skeletal lesions in fibrous dysplasia and the relationship to functional outcome

Most lesions in FD and their attendant functional disability occur within the first decade; 90% of lesions are present by 15 years, and the median age when assistive devices are needed is 7 years. These findings have implications for prognosis and determining the timing and type of therapy.

INTRODUCTION

Fibrous dysplasia of bone (FD) is an uncommon skeletal disorder in which normal bone is replaced by abnormal fibro-osseous tissue. Variable amounts of skeletal involvement and disability occur. The age at which lesions are established, the pace at which the disease progresses, if (or when) the disease plateaus, and how these parameters relate to the onset of disability are unknown. To answer these questions, we performed a retrospective analysis of a group of subjects with FD.

MATERIALS AND METHODS

One hundred nine subjects with a spectrum of FD were studied for up to 32 years. Disease progression was assessed in serial (99)Tc-MDP bone scans by determining the location and extent of FD lesions using a validated bone scan scoring tool. Physical function and the need for ambulatory aids were assessed.

RESULTS

Ninety percent of the total body disease skeletal burden was established by age 15. Disease was established in a region-specific pattern; in the craniofacial region, 90% of the lesions were present by 3.4 yr, in the extremities, 90% were present by 13.7 yr, and in the axial skeleton, 90% were present by 15.5 yr. Twenty-five of 103 subjects eventually needed ambulatory aids. The median age at which assistance was needed was 7 yr (range, 1-43 yr). The median bone scan score for subjects needing assistance was 64.3 (range, 18.6-75) compared with 23.1 (range, 0.5-63.5) in the unassisted subjects (p < 0.0001). Among subjects needing assistance with ambulation, 92% showed this need by 17 yr.

CONCLUSIONS

The majority of skeletal lesions and the associated functional disability occur within the first decade of life. The implication is that the window of time for preventative therapies is narrow. Likewise, therapeutic interventions must be tailored to where the patient is in the natural history of the disease (i.e., progressive disease [young] versus established disease [older subjects]). These findings have implications for prognosis, the timing and type of therapy, and the development of trials of new therapies and their interpretation.

The spectrum of McCune Albright syndrome

Since the original description of McCune Albright syndrome, the clinical spectrum of fibrous dysplasia, café au lait marks and precocious puberty has been enlarged to include multiple features within an individual or forme fruste of the disorder. This review serves as an introduction to a more detailed analysis of individual organ involvement in later papers. Recent insights into molecular pathways and recognition of overlap between clinical syndromes and signaling pathways of embryonic cellular differentiation, growth and function of many tissues, has improved understanding of this complex disorder. The article touches briefly on the underlying stimulatory G protein mutations with their mosaic distribution in tissues. Fibrous dysplasia, associated malignancies and endocrinopathies are discussed, including gonadotrophin independent precocious puberty in females and males, thyroid disease, acromegaly and Cushing syndrome. Café au lait marks are an overlapping feature seen in other signaling disorders. Their management is discussed.

McCune-Albright syndrome in adulthood

The McCune-Albright syndrome is characterized by cafe-au-lait spots, precocious puberty and fibrous dysplasia. It is due to mutations in the gene encoding the Gs protein alpha subunit coupling 7-transmembrane-domain receptors to adenylate cyclase, leading to constitutive adenylate cyclase activation and cAMP overproduction. Endocrinologists, rheumatologists and gynecologists are confronted with new issues when these children reach adulthood. Dysplastic bone lesions seem to stabilize after puberty, but their disabling consequences (pain, fractures, etc.) may continue into adulthood. Gonadal function and fertility are often abnormal in women in whom puberty was precocious, owing to the persistence of a variable degree of ovarian autonomy that hinders adequate follicular development and ovulation. Acromegaly, when present, is often difficult to treat surgically because of skull-base dysplasia. Somatostatin analogs are only partially effective in most cases; fortunately, the GH receptor antagonist, pegvisomant may be more effective in normalizing IGF-I levels. Hyperthyroidism, generally due to multinodular toxic goiter, can be successfully treated by surgery or radioiodine administration. Recent data suggest that cancer incidence in adulthood (bone, breast, thyroid...) is increased in these patients.

Common fibro-osseous lesions of the paranasal sinuses

Within in the broad spectrum of disease that can affect the paranasal sinuses is a class of benign bony abnormalities known collectively as fibro-osseous lesions. Fibrous dysplasia, ossifying fibroma, and osteoma are three distinct entities that lie along a continuum from the least to the most bony content. They have similar appearance and makeup; however, their clinical implications vary. This article focuses primarily on sinonasal osteomas, with less emphasis on fibrous dysplasia and ossifying fibroma.

Physical function is impaired but quality of life preserved in patients with fibrous dysplasia of bone

Fibrous dysplasia of bone (FD) is a congenital, non-heritable skeletal disorder that is associated with multiple skeletal complications, including repeated fractures, limb length discrepancy, and bone pain. The disease-specific impact of FD on quality of life outcomes is unknown. We sought to understand the impact of the scope and extent of the skeletal disease on quality of life in adults and children with FD. The health-related quality of life was quantified in a population of adults (n = 56) and children (n = 22) with FD using validated health assessment questionnaires, the Medical Outcomes Study 36 Item Short-Form Health Survey, volume 2 (SF36) (adults) and the Child Health Questionnaire Parent Form 50 (CHQ-PF50) (children). Clinical demographic data and skeletal disease burden scores (SDBS, amount of skeleton involved with FD) were measured, and correlations with health-related quality of life were sought. The SF36 and CHQ-PF50 revealed lower Physical Function Summary scores in FD patients compared to the U.S. population norms (adult 41 vs. 50, Z score < -5.0, pediatric 39 vs. 50, Z score < -5.0). However, the SF36 and CHQ-PF50 Mental/Psychological summary scores were not different from those of U.S. population norms (adult 50 vs. 50, Z score = 0, pediatric 48 vs. 50 Z score = -0.9). The score on the Physical Function Domain of both tools was strongly negatively associated with the SDBS (adult Spearman rho = -0.43, P = 0.009, pediatric Spearman rho = -0.72, P = 0.005). The groups of adult and pediatric patients with SDBS > 30 had decreased Physical Function Domain scores when compared to those with scores < 30 (adult 35 vs. 45, P = 0.002, pediatric 57 vs. 78, P = 0.04, respectively). One of the largest effects was seen in the parents of children with FD, who had significantly lower Parental Emotional scores than those of the parents of healthy norms (54 vs. 88, Z score < -5.0), suggesting a high degree of emotional morbidity in the parents of children with FD. Despite measurable functional limitations in adults and children, and significant parental emotional impairment, patients with FD achieve a high level of social and emotional function. These data are important for prognosis and parental reassurance.

Fibrous dysplasia. Pathophysiology, evaluation, and treatment

Fibrous dysplasia is a common benign skeletal lesion that may involve one bone (monostotic) or multiple bones (polyostotic) and occurs throughout the skeleton with a predilection for the long bones, ribs, and craniofacial bones. The etiology of fibrous dysplasia has been linked to an activating mutation in the gene that encodes the alpha subunit of stimulatory G protein (G(s)alpha) located at 20q13.2-13.3. Most lesions are monostotic, asymptomatic, and identified incidentally and can be treated with clinical observation and patient education. Bisphosphonate therapy may help to improve function, decrease pain, and lower fracture risk in appropriately selected patients with fibrous dysplasia. Surgery is indicated for confirmatory biopsy, correction of deformity, prevention of pathologic fracture, and/or eradication of symptomatic lesions. The use of cortical grafts is preferred over cancellous grafts or bone-graft substitutes because of the superior physical qualities of remodeled cortical bone.

Osteoclastogenesis in fibrous dysplasia of bone: in situ and in vitro analysis of IL-6 expression

Fibrous dysplasia of bone (FD) is caused by somatic mutations of the GNAS1 gene, which lead to constitutive activation of adenylyl cyclase and overproduction of cAMP in osteogenic cells. Previous in vitro studies using nonclonal, heterogeneous strains of FD-derived cells suggested that IL-6 might play a critical role in promoting excess osteoclastogenesis in FD. In this study, we investigated IL-6 expression in FD in situ and its relationship to the actual patterns of osteoclastogenesis within the abnormal tissue. We found that osteoclastogenesis is not spatially restricted to bone surfaces in FD but occurs to a large extent ectopicly in the fibrous tissue, where stromal cells diffusely express IL-6 mRNA and exhibit a characteristic cell morphology. We also observed specific expression of IL-6 mRNA in a proportion of osteoclasts, suggesting that an autocrine/paracrine loop may contribute to osteoclastogenesis in vivo in FD, as in some other bone diseases, including Paget's disease. We also generated homogeneous, clonally derived strains of wild-type and GNAS1-mutated stromal cells from the same individual, parent FD lesions. In this way, we could show that mutated stromal cells produce IL-6 at a basal magnitude and rate that are significantly higher than in the cognate wild-type cells. Conversely, wild-type cells respond to db-cAMP with a severalfold increase in magnitude and rate of IL-6 production, whereas mutant strains remain essentially unresponsive. Our data establish a direct link between GNAS1 mutations in stromal cells and IL-6 production but also define the complexity of the role of IL-6 in regulating osteoclastogenesis in FD in vivo. Here, patterns of osteoclastogenesis and bone resorption reflect not only the cell-autonomous effects of GNAS1 mutations in osteogenic cells (including IL-6 production) but also the local and systemic context to which non-osteogenic cells, local proportions of wild-type vs mutated cells, and systemic hormones contribute.

Fibrous dysplasia associated with intramuscular myxoma (Mazabraud's syndrome): a long-term follow-up of three cases

The association between of fibrous dysplasia and intramuscular myxomas is extremely rare. The authors summarize the characteristics of Mazabraud's syndrome, as well as its clinical course on the basis of 24 cases reported in the literature and 3 cases of their own. The syndrome is quite uniform, and mostly occurs in women. Usually the presentation of poliostotic fibrous dysplasia bilaterally in the lower limbs and pelvic bones is followed by the appearance of multifocal intramuscular myxomas in the adjacent muscles, mostly decades later. These hamartomas tend to recur locally or symmetrically in the ipsilateral muscle groups and may reach enormous size without treatment. Malignant transformation (osteosarcoma, fibrosarcoma) on the basis of fibrous dysplasia in Mazabraud's syndrome has been reported in the literature. In our cases, however, in spite of the many recurrences, and the enormous size of the tumours, no malignant transformation was noted in either the fibrous dysplasias or the intramuscular myxomas during the long follow-up time (31 years for fibrous dysplasia and 16 years for myxomas). Early wide surgical excision and a careful long-term follow-up for the often very late recurrences of the myxomas is suggested in Mazabraud's syndrome.

Fibrous dysplasia of the craniomaxillofacial region: current clinical perspectives

Fibrous dysplasia is a benign fibro-osseous disease of bone of unknown etiology. Its occurrence in the craniomaxillofacial skeleton is frequent and varies in severity from an asymptomatic monostotic lesion to polyostotic involvement resulting in progressive functional deficit and aesthetic problems. With the advent of refined instrumentation and craniofacial surgical techniques, a more aggressive, non-disabling approach to these benign yet deforming fibro-osseous growths is possible. In some patients, complete excision of the involved bone with graft reconstruction of the resultant defect with primary autogenous bone may be possible. Lifelong continuous ongoing monitoring of the involved region is required throughout the patient's life.

Fibrous dysplasia in paranasal cavities

Presentation is made of 2 boys and a girl with fibrous dysplasia involving the frontal and ethmoidal sinuses and the maxilla. This tumor-like growth of the bone was not restricted to the sinus alone but expanded to the orbit, adjacent sinus, skull base and infratemporal or pterygoid fossa. In such cases, surgical therapy is the treatment of choice, with maximal preservation of healthy tissue and avoidance of major devastations that may result in undesired cosmetic defects. The etiology of the disease is still unknown. However, it should be emphasized that all 3 patients had suffered an injury to the adjacent bony structures at various time points preceding the disease manifestation. That is why we are inclined to believe that trauma might be a factor responsible for the onset of fibrous dysplasia.

An unusual case of mixed sclerosing bone dystrophy presenting with morning stiffness and joint swelling in childhood: a case report

We describe a case of a 16 year old native Indian girl with pain, morning stiffness and foot swelling who had radiographic changes consistent with mixed sclerosing bone dystrophy (MSBD) combined with fibrous dysplasia.

Serial observation of asymmetry in the growing face

Three children suffering from facial asymmetry were observed annually using facial stereophotogrammetry before, during, and after their general skeletal adolescent growth spurt. Stereophotogrammetry allows accurate three-dimensional measurements between identifiable facial landmarks. Five pairs of bilateral parameters connecting external canthi and angles of the mouth to alae and tip of nose, and to each other, allowed a positive sign (right-side larger) or a negative (left-side larger) assessment of parameter asymmetry. Their total, taking sign into account, assessed mid-facial asymmetry. Serial observation showed that: (1) in patient no. 1 suffering from post-traumatic condylar hypoplasia, the facial asymmetry resolved; (2) in patient no. 2 suffering from unilateral facial hypoplasia, the asymmetry, which was severe, reduced with adolescence, but did not resolve; (3) in patient no. 3 suffering from fibro-osseous dysplasia of left maxilla, the asymmetry was reduced by surgery, but the full effects of the surgery were not measurable until over 1 year after operation; subsequently, the asymmetry began to increase again.

Focal fibrocartilaginous dysplasia: consideration of healing process

We report two patients with unilateral tibia vara due to focal fibrocartilaginous dysplasia of the medial aspect of the proximal tibia. It appears that tibia vara, caused by a primary self-limited lesion at the proximal medial metaphysis, is corrected by the response of the proximal tibial physis. This finding would indicate that an infantile growth plate of the proximal tibia has a rather large potential to correct an angular deformity at the adjacent metaphysis.

Parathyroid hormone and cardiovascular effects of dihydropyridines in chronic renal failure

We studied the influence of parathyroid gland activity on cardiovascular response to dihydropyridines (nicardipine (NIC), 80 mg/day for 4 weeks) in 20 hypertensive patients with end-stage renal failure (ESRF). Before the treatment hyperparathyroidism (HPTH) was estimated on the basis of serum parathormone (PTH), and bone histomorphometry (osteoclastic resorption surfaces (ORS), and number of osteoclasts (NO]. NIC induced a significant decrease in systolic (SAP) and diastolic (DAP) arterial blood pressure, but did not significantly change the heart rate (HR) or the SAP X HR (myocardial oxygen consumption estimate). Changes in SAP and DAP were correlated to baseline serum PTH (P less than .001), to ORS (P less than .01) and to NO (P less than .01). Furthermore, a significant decrease in blood pressure was observed only in patients with histological signs of hyperparathyroidism (ORS greater than 1%). In this subset of patients NIC induced a significant decrease in SAP X HR (P less than .02) which was correlated to PTH and histomorphometric indexes of HPTH (P less than .01). The results of the present study show that blood pressure response to dihydropyridines in ESRF is associated with parathyroid activity as judged from serum PTH and bone histomorphometry.

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.

[Studies on internal pressure and oxygen tension of bone tumors and tumor conditions. II--Growth rate, internal pressure and oxygen tension in bone lesions]

Internal pressure and oxygen tension were measured in 24 patients with bone tumors and tumorous conditions. High internal pressure were observed in most of the rapidly growing lesions. The internal pressure of slowly growing and non-growing lesions were not significantly different from those of normal bone marrow. Oxygen tension was commonly higher in the rapidly growing lesions than in simultaneously obtained peripheral venous samples from the same patients. A high correlation was found between internal pressure and the growth rate of the bone lesions in this study. These data suggest that internal pressure and oxygen tension of the lesions reflect the degree of blood supply to the bone tumors and tumorous conditions.

McCune-Albright syndrome. Long-term follow-up

This article describes clinical follow-up of 15 patients--13 females and two males--with McCune-Albright syndrome. Osseous fractures occurred only during childhood, while hearing impairment due to temporal bone involvement occurred in four of six adults. Four females with precocious puberty had final heights that were not different from the mean for normal females; they eventually developed regular menses, and two had children. Persistent hyperthyroidism requiring ablative therapy occurred in three subjects, while hypophosphatemia occurred in three subjects. The protean manifestations of this disorder suggest that it results from a basic defect of cellular regulation. We postulate that its varied endocrine abnormalities result from altered regulation of intracellular cyclic adenosine monophosphate effects.

The McCune-Albright syndrome

The presence of polyostotic fibrous dysplasia of bone, hyperpigmented skin macules, and precocious sexual development in children is known as the McCune-Albright syndrome. To date, a complex combination of multiple endocrinopathies including goiter, hyperthyroidism, acromegaly, Cushing syndrome, hyperprolactinemia, sexual precocity, hyperparathyroidism, and hypophosphatemic hyperphosphaturic rickets have been described in association with this syndrome. Even though the pathogenetic mechanisms involved in the development of the endocrinopathies is unknown, it was assumed for many years that hypothalamic dysfunction was the cause in most cases. The overwhelming amount of data now permits the development of an alternate hypothesis; one of hyperfunctioning endocrine organs working with relative autonomy from hypothalamic control.

Ovarian function in girls with McCune-Albright syndrome

We measured plasma estradiol levels and ovarian volumes in eight girls with precocious puberty due to McCune-Albright syndrome. Six girls had gonadotropin-independent ovarian estrogen secretion and two girls had pubertal gonadotropin levels. Mean ovarian volume in all patients was significantly greater than in normal prepubertal girls. Mean ovarian volumes of the girls with McCune-Albright syndrome overlapped the range found in girls with idiopathic central precocious puberty or central precocious puberty associated with central nervous system lesions. However, the degree of asymmetry between the right and left ovaries was significantly greater in girls with McCune-Albright syndrome. Asymmetry was due, for the most part, to the presence of large solitary cysts in the larger of the two ovaries. In the six girls with McCune-Albright syndrome and gonadotropin-independent precocious puberty, both mean ovarian volume and the degree of asymmetry between the right and left ovaries were significantly correlated with plasma estradiol. Serum follicle-stimulating hormone bioactivity was increased in two patients but did not vary with ovarian cyst size. Thyroid-stimulating hormone levels were normal but serum prolactin was slightly elevated in one of the six girls with gonadotropin-independent precocious puberty. Fluctuation in the size of unilateral ovarian cysts appears to result in changes in the plasma estradiol level, leading to advancement and spontaneous regression of secondary sexual characteristics and menses in girls with McCune-Albright syndrome. The cause of the cyst formation is unknown but may be related to periodic elevation of as yet undefined serum factors such as follicle-stimulating hormone bioactive substances.

Autonomous ovarian hyperfunction followed by gonadotrophin-dependent puberty in McCune-Albright syndrome

A 5-year-old girl with the McCune-Albright syndrome presented with precocious puberty secondary to autonomously functioning ovarian cysts, followed by true central puberty. Progression from gonadotrophin-independent to gonadotrophin-dependent precocious puberty may occur from elevated sex steroid levels leading to the early maturation of the hypothalamic-pituitary axis.

Occurrence of pituitary adenoma in craniofacial fibrous dysplasia: a neuroendocrine and neuroradiological case study

An 18 year old man with fibrous dysplasia of bone and several endocrine abnormalities was investigated. Laboratory tests showed high levels of prolactin, TSH and GH and low levels of testosterone and LH. TRH and GnRH showed normal responsiveness of the pituitary in spite of the high hormonal levels. The circadian rhythms disclosed no abnormalities of hypothalamic control. The neuroradiological study revealed pathological tissue but no positive sign of a pituitary adenoma, although the sella turcica polytomograms did suggest erosion of the floor. Our data are compatible with the presence of a mixed adenoma or adenomas of the pituitary. We emphasize the importance of a correct study, including neuroradiological and neuroendocrine investigations, in patients with fibrous dysplasia of bone.

Acromegaly and hyperprolactinemia in McCune-Albright syndrome. Evidence of hypothalamic dysfunction

In a 21-year-old woman with McCune-Albright syndrome, acromegaly and hyperprolactinemia with hypopituitarism developed secondary to a large pituitary tumor. Bromocriptine suppressed the secretion of growth hormone and prolactin, with a reduction in tumor size. However, at the age of 8, she already showed evidence of biochemical acromegaly, with a paradoxical rise of growth hormone levels during two glucose tolerance tests, in the presence of a radiologically normal pituitary fossa. These data support the hypothesis that long-standing hypothalamic stimulation may have been responsible for the later development of a pituitary tumor.

Abnormal hypothalamic-pituitary function in polyostotic fibrous dysplasia

Hypothalamic-pituitary dysfunction was found in two patients with polyostotic fibrous dysplasia and leontiasis ossea. Both patients probably had McCune--Albright syndrome with early sexual development, disfiguring craniofacial bone lesions, cutaneous hyperpigmentation and gigantism in childhood. Endocrinological studies revealed measurable plasma growth hormone throughout a 24-h sampling period with preservation of sleep augmented rises. The mean 24-h values were 329 and 7 ng/ml, respectively. Both their mean plasma prolactin concentrations, 385 and 45 ng/ml, and the 24-h secretory patterns of prolactin were abnormal. One patient had an elevated mean plasma cortisol concentration of 8.5 micrograms/dl but the 24-h pattern of cortisol secretion was normal. Basal plasma LH, FSH, TSH, T4 and T3 concentrations were normal but neither patient had a TSH response to TRH. Prolactin and growth hormone secretions were, however, increased after TRH. Oral glucose resulted in partial suppression of GH but an exaggerated insulin response in both patients. Post-mortem in one patient revealed a thick calvarium with bony encasement of the pituitary gland. The pituitary and hypothalamus appeared normal on gross, light microscopic and electronmicroscopic examination. These data strongly suggest the presence of hypothalamic-pituitary dysfunction in these two patients.