Chronic Nonbacterial Osteomyelitis of the Sternocostoclavicular Region in Adults: A Single-Center Dutch Cohort Study.

Sternocostoclavicular hyperostosis (SCCH) is a rare autoinflammatory bone disorder caused by chronic nonbacterial osteomyelitis (CNO), which is associated with sclerosis and hyperostosis primarily affecting the sternum, the medial end of the clavicles, and the first ribs. Other areas of the axial skeleton may also be affected. The more severe synovitis-acne-pustulosis-hyperostosis-osteitis (SAPHO) syndrome is additionally associated with dermatoses and joint manifestations. This Dutch retrospective cross-sectional single-center cohort study characterizes the spectrum of clinical features in adult CNO/SCCH patients at the time of diagnosis. The only inclusion criteria was the availability of complete sets of clinical and imaging data systematically collected over three decades using in-house protocols. Data from 213 predominantly female patients (88%) with a median age of 36 years at presentation were studied. The mean diagnostic delay was 5 ± 5 years. The main symptoms were chronic pain (92%), bony swelling (61%), and restricted shoulder girdle function (46%); 32% had palmoplantar pustulosis and 22% had autoimmune disease. The majority (73%) had isolated SCCH; 59 (27%) had additional localizations in vertebrae (19%), the mandible (9%), or both (2%); 4 had SAPHO. The prevalence of current or past smoking was high (58%), particularly for patients with palmoplantar pustulosis (76%). There was a significant relationship between delay in diagnosis and both the extent of affected skeletal sites (p = 0.036) and erythrocyte sedimentation rate levels (p = 0.023). Adult-onset CNO is characterized by distinctive clinical and radiological features, but diverse aspects of its spectrum are currently not fully captured by a comprehensive classification. Delayed diagnosis is still common and potentially associated with irreversible structural changes and debilitating chronic symptoms, increasing the burden of illness and negatively impacting on quality of life. It is hoped that findings from this study will dispel confusion about nomenclature and classification of adult-onset CNO and increase awareness of its distinctive clinical and radiological features, and thus facilitate early diagnosis and referral for treatment, which should positively impact prognosis by preventing disease progression, although this remains to be established. © 2021 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Increased Risk of Breast Cancer at a Young Age in Women with Fibrous Dysplasia.

Fibrous dysplasia (FD) is a rare bone disorder caused by mutations of the GNAS gene, which are also identified in malignancies. We explored the potential relationship between breast cancer and fibrous dysplasia in two fibrous dysplasia cohorts from the Netherlands and the United States. Data on fibrous dysplasia and breast cancer diagnosis were retrieved from hospital records of 134 (Netherlands) and 121 (US) female patients. Results were validated with breast cancer data of 645 female fibrous dysplasia patients from the Dutch Pathology Registry (PALGA). Standardized morbidity ratios for breast cancer were estimated with data from Dutch and US general population registries. GNAS mutation was analyzed in 9 available breast cancer specimens. A combined total of 15 patients (6 polyostotic, 9 McCune-Albright Syndrome) had breast cancer (87% thoracic localizations). In the Netherlands, a breast cancer incidence rate of 7.5% at median age of 46 years was validated in PALGA (6.5% at age 51 years). Breast cancer risk was 3.4-fold increased (95% confidence interval [CI] 1.6-5.9) compared with the Dutch general population; OR 13.2-fold (95% CI 6.2-22.8) in thoracic disease. In the US cohort, breast cancer incidence rate was 4.5% at a median age of 36 years. Breast cancer risk was 3.9-fold increased (95% CI 1.2-8.2) compared with the general population; 5.7-fold (95% CI 1.4-13.0) in thoracic disease. GNAS mutation was positive in 4 breast cancer specimens (44%). Risk of breast cancer is increased at a younger age, particularly in polyostotic FD, suggesting that screening for breast cancer should be considered in this particular group at a younger age than currently advocated by national guidelines. © 2017 American Society for Bone and Mineral Research.

Outcome of Long-Term Bisphosphonate Therapy in McCune-Albright Syndrome and Polyostotic Fibrous Dysplasia.

McCune-Albright syndrome (MAS) is a rare bone disorder characterized by fibrous dysplasia (FD), endocrinopathies, and café-au-lait patches. FD patients have been shown to respond favorably to treatment with bisphosphonates, but data are scarce in the more severe polyostotic form (PFD), including MAS, and factors determining treatment outcome are not known, particularly in the long-term. We evaluated the biochemical (bone turnover markers [BTMs]) and clinical (pain reduction) outcome of bisphosphonate therapy in 11 patients with MAS and 30 patients with PFD: median duration of treatment 6 years (range, 2 to 25 years). Prognostic factors for treatment outcome were identified in both groups. Patients with MAS were younger at diagnosis (p = 0.001), all had precocious puberty, and four (36%) had additional growth hormone (GH) excess associated with severe craniofacial FD. Extent of skeletal disease was more severe in MAS compared to PFD. MAS patients had higher serum alkaline phosphatase (ALP) concentrations (p = 0.005), higher skeletal burden scores (p < 0.001), and more fractures (p = 0.021). MAS patients had also higher levels of FGF-23 (p = 0.008) and higher prevalence of hypophosphatemia (p = 0.013). Twenty-four of 30 PFD patients (80%) demonstrated a complete clinical and biochemical response within a year of starting treatment (p = 0.015), compared to only four of 11 MAS patients (36%). There were no nonresponders. In the whole group, FGF-23, total ALP, P1NP, and CTX positively correlated with skeletal burden scores (all p ≤ 0.001), which was the only significant risk factor for an incomplete response to bisphosphonate therapy (p < 0.01). Our data suggest a beneficial and safe outcome of long-term bisphosphonate therapy in the majority of patients with PFD, although response to therapy was limited by the higher skeletal disease burden in MAS patients. In the PFD/MAS population studied, the only identified prognostic factor that influenced the outcome of bisphosphonate therapy was a high skeletal burden score. © 2016 American Society for Bone and Mineral Research.

Patients with sclerosteosis and disease carriers: human models of the effect of sclerostin on bone turnover.

Sclerosteosis is a rare bone sclerosing dysplasia, caused by loss-of-function mutations in the SOST gene, encoding sclerostin, a negative regulator of bone formation. The purpose of this study was to determine how the lack of sclerostin affects bone turnover in patients with sclerosteosis and to assess whether sclerostin synthesis is decreased in carriers of the SOST mutation and, if so, to what extent this would affect their phenotype and bone formation. We measured sclerostin, procollagen type 1 amino-terminal propeptide (P1NP), and cross-linked C-telopeptide (CTX) in serum of 19 patients with sclerosteosis, 26 heterozygous carriers of the C69T SOST mutation, and 77 healthy controls. Chips of compact bone discarded during routine surgery were also examined from 6 patients and 4 controls. Sclerostin was undetectable in serum of patients but was measurable in all carriers (mean 15.5 pg/mL; 95% confidence interval [CI] 13.7 to 17.2 pg/mL), in whom it was significantly lower than in healthy controls (mean 40.0 pg/mL; 95% CI 36.9 to 42.7 pg/mL; p < 0.001). P1NP levels were highest in patients (mean 153.7 ng/mL; 95% CI 100.5 to 206.9 ng/mL; p = 0.01 versus carriers, p = 0.002 versus controls), but carriers also had significantly higher P1NP levels (mean 58.3 ng/mL; 95% CI 47.0 to 69.6 ng/mL) than controls (mean 37.8 ng/mL; 95% CI 34.9 to 42.0 ng/mL; p = 0.006). In patients and carriers, P1NP levels declined with age, reaching a plateau after the age of 20 years. Serum sclerostin and P1NP were negatively correlated in carriers and age- and gender-matched controls (r = 0.40, p = 0.008). Mean CTX levels were well within the normal range and did not differ between patients and disease carriers after adjusting for age (p = 0.22). Our results provide in vivo evidence of increased bone formation caused by the absence or decreased synthesis of sclerostin in humans. They also suggest that inhibition of sclerostin can be titrated because the decreased sclerostin levels in disease carriers did not lead to any of the symptoms or complications of the disease but had a positive effect on bone mass. Further studies are needed to clarify the role of sclerostin on bone resorption.

A patient with persistent primary hyperparathyroidism due to a second ectopic adenoma.

BACKGROUND: A 33-year-old woman presented with recurrent renal stones and malaise to her primary-care physician. Laboratory investigations revealed the patient had hypercalcemia and an elevated serum parathyroid hormone concentration. A diagnosis of primary hyperparathyroidism was established and the patient was referred for parathyroidectomy. At neck exploration, three parathyroid glands were visualized, one of which was enlarged and subsequently removed. The patient's serum calcium and parathyroid hormone levels decreased postoperatively but did not normalize, and her symptoms persisted. Planar (99m)Tc-sestamibi and ultrasound scans failed to provide conclusive localization for another enlarged parathyroid gland. The patient was referred to our Endocrinology Unit for further investigations and management. INVESTIGATIONS: Laboratory investigations, ultrasound of the kidneys, BMD measurements, selective venous sampling for parathyroid hormone, and (99m)Tc-sestamibi single photon emission CT imaging. DIAGNOSIS: Persistent hyperparathyroidism due to an ectopically located parathyroid adenoma. MANAGEMENT: At further neck exploration, a 1.5 cm by 0.7 cm by 0.5 cm ectopic parathyroid adenoma was excised from the site indicated by the localization studies. No further exploration was attempted after intraoperative parathyroid hormone levels fell by 70%. Serum calcium levels and 24 h urine excretion of calcium rapidly normalized and all of the patient's symptoms completely disappeared within a few weeks of surgery.