Open Surgical Hip Dislocation for an Acetabular Osteoid Osteoma - A Case Report

Osteoid osteoma is a benign tumor that accounts for roughly 10-12% of all benign bone forming tumors. This tumor generally occurs within the first three decades of life and occurs more commonly in males. This lesion is painful and is generally worse at night and has relief of symptoms with the use of NSAIDs. Osteoid osteoma is characterized by the production of osteoid surrounded by a rim of sclerotic bone. These lesions most commonly occur in long bones such as the proximal femur, however they can occur anywhere. Rarely, as with our patient, have these lesions been reported in the acetabulum.

Pediatric Erdheim-Chester Disease in the Molecular Era: A Multicenter Case Series

Background: Erdheim-Chester disease (ECD) is a non-Langerhans cell histiocytic disorder that almost exclusively affects adults. Reports of pediatric-onset ECD are only anecdotal. Additionally, a comprehensive clinical and molecular characterization of pediatric ECD is lacking. Methods: All prevalent and incident cases followed at three ECD referral centers in Italy and France were considered eligible when they had: a) an age <18y at disease onset; b) a clinical presentation consistent with ECD (i.e., at least one of the following localizations: bilateral, sclerotic bone involvement; sclerotic bone lesions of facial sinuses; hairy kidneys; coated aorta; xanthelasma; tumoral atrial involvement); c) pathology consistent with ECD or mixed ECD-Langerhans cell histiocytosis (LCH); d) available data on molecular studies. Results: Ten patients were included (4 boys and 6 girls); their median age at diagnosis was 4.5 years (IQR 3-9). Bone pain, diabetes insipidus, and exophthalmos were the predominant clinical manifestations at onset. The most commonly involved sites were the hypothalamic/pituitary axis (8/10, 80%), the maxillary/facial structures (8/10, 80%), the bone (6/10, 60%), and the central nervous system (CNS; 7/10, 70%). Other less frequent localizations included the skin (3/10, 30%), the retroperitoneum (2/10, 20%), the lymph nodes (2/10, 20%), the large vessels (1/10, 10%), the heart (1/10, 10%), and the lung (1/10, 10%). The median number of involved sites was four (IQR 4-4). Four patients (of whom three were younger than nine years) had clinical or pathological features consistent with mixed histiocytosis (ECD-LCH). Molecular analysis of tissue biopsies revealed the BRAF V600E mutation in 6 patients (60%). As compared with adult series, the retroperitoneum, the heart, the lungs, and the skin seemed to be less frequently involved. Conversely, hypothalamic/pituitary and maxillary/facial involvement were apparently more frequent in our pediatric cohort. Treatments were heterogeneous. First-line regimens mainly consisted of chemotherapy deriving from LCH-based regimens: six out of the eight treated patients received chemotherapy, but only two of them achieved a transient response. Interferon-alpha was used in five patients (as first-line treatment in two and as a rescue treatment in three), with a partial response in two. Four patients with the BRAF V600E mutation received the BRAF inhibitor vemurafenib at some point (partial responses were obtained in all, in one case requiring a combination with cobimetinib). All patients were alive at last follow up (median 94 months, IQR 12-108). Chronic sequelae included end-stage kidney disease in one patient, growth retardation in two, and endocrine abnormalities in seven. Conclusions: The clinical phenotype of ECD differs between children and adults. The hypothalamic/pituitary axis and the maxillary/facial area are frequently involved in pediatric cases, whereas other localizations typically seen in adults (i.e., retroperitoneum, heart, lung, and skin) are rarer. An overlap with LCH is frequent, especially in younger patients. As for LCH, targeted treatments can be highly effective in children carrying the BRAF V600Emutation. Disclosures No relevant conflicts of interest to declare.

Enostosis-related epilepsy

Unexpected bone lesions of the skull present a common dilemma, where radiological appearance and patient’s clinical background are crucial to avoid misdiagnosis. Enostosis are benign sclerotic bone lesions; its aetiology is still unknown and its management is usually conservative, with good prognosis. Most of these lesions are asymptomatic and neurological involvement is rare. We present the first report of enostosis-related epilepsy.

Primary Sjögren’s syndrome manifesting as sclerotic metabolic bone disease

Primary Sjögren’s syndrome (pSS) is a chronic slowly progressive autoimmune disease characterised by lymphocytic infiltration of salivary and lacrimal glands with varying degree of systemic involvement. Renal involvement, a recognised extraglandular manifestation of pSS, is commonly related to tubular dysfunction and generally manifests as distal renal tubular acidosis (RTA), proximal RTA, tubular proteinuria and nephrogenic diabetes insipidus. Untreated long-standing RTA is known to cause metabolic bone disease. Here, we present the report of a patient with sclerotic metabolic bone disease related to pSS with combined distal and proximal RTA and negative workup for other causes of sclerotic bone disease. A significant clinical and biochemical improvement, including recovery of proximal tubular dysfunction, was noted with alkali therapy. This case suggests the need to consider pSS in the diagnostic algorithm of a patient presenting with sclerotic bone disease.

A Retrospective Comparative Study of Sodium Fluoride (NaF-18)-PET/CT and Fluorocholine (F-18-CH) PET/CT in the Evaluation of Skeletal Metastases in Metastatic Prostate Cancer Using a Volumetric 3-D Radiomics Analysis

Bone metastases are common in prostate cancer (PCa). Fluorocholine-18 (FCH) and sodium fluoride-18 (NaF) have been used to assess PCa associated skeletal disease in thousands of patients by demonstrating different mechanism of uptake-cell membrane (lipid) synthesis and bone mineralization. Here, this difference is characterized quantitatively in detail. Our study cohort consisted of 12 patients with advanced disease (> 5 lesions) (M) and of five PCa patients with no skeletal disease (N). They had routine PET/CT with FCH and NaF on consecutive days. Skeletal regions in CT were used to co-register the two PET/CT scans. Bone 3-D volume of interest (VOI) was defined on the CT of PET with a threshold of HU > 150, and sclerotic/dense bone as HU > 600, respectively. Additional VOIs were defined on PET uptake with the threshold values on both FCH (SUV > 3.5) and NaF (SUV > 10). The pathologic skeletal volumes for each technique (CT, HU > 600), NaF (SUV > 10) and FCH (SUV > 3.5) were developed and analyzed. The skeletal VOIs varied from 5.03 L to 7.31 L, whereas sclerotic bone VOIs were from 0.88 L to 2.99 L. Total choline kinase (cell membrane synthesis) activity for FCH (TCA) varied from 0.008 to 4.85 [kg] in M group and from 0.0006 to 0.085 [kg] in N group. Total accelerated osteoblastic (bone demineralization) activity for NaF (TBA varied from 0.25 to 13.6 [kg] in M group and varied from 0.000 to 1.09 [kg] in N group. The sclerotic bone volume represented only 1.86 ± 1.71% of the pathologic FCH volume and 4.07 ± 3.21% of the pathologic NaF volume in M group, and only 0.08 ± 0.09% and 0.18 ± 0.19% in N group, respectively. Our results suggest that CT alone cannot be used for the assessment of the extent of active metastatic skeletal disease in PCa. NaF and FCH give complementary information about the activity of the skeletal disease, improving diagnosis and disease staging.

False-Positive 18F-FDG PET/CT Uptake in Unilateral Lactation

A 31-year-old woman (7 months postpartum and lactating) with multiple sclerotic bone lesions was referred for an 18F-FDG PET/CT scan for characterization. The scan demonstrated unilateral diffuse intense FDG uptake corresponding to dense soft tissue in the right breast, likely related to secretory hyperplasia. On further questioning, it was made apparent that she had only been breastfeeding from the right breast. While the left breast also demonstrated dense soft tissue to a lesser degree, no significant FDG uptake was seen. The sclerotic bone lesions were not FDG avid, likely due to a separate non-FDG avid benign condition or bony metastases from a non-FDG avid primary malignancy. This was reinforced by the fact that subsequent investigations including serial bilateral breast ultrasound and percutaneous biopsy demonstrated no definite evidence of malignancy in the bilateral breasts. The histopathology findings of an open surgical biopsy of sclerotic lesions in the left posterior ilium were also nonspecific, favouring bone dysplasia with no evidence of malignancy.

Dynamic evolution of osseous structure in osteonecrosis of the femoral head and dynamic collapse risks: a preliminary CT image study

Background Collapse risk of osteonecrosis of the femoral head (ONFH) is estimated mainly based on static indicators, including lesion size and lesion location, but bone repairing is a dynamic process that lasts for years. The present study attempted to analyze the dynamic evolution of the osseous structure and its correlation with radiographic progression. Methods This retrospective study included 50 hips with ONFH from 50 patients. Participants were divided into the non-collapse group (n = 25) and the collapse group (n = 25). Original files of the initial computed tomography (CT) images were imported into imaging processing software for morphology analysis. The volume of sclerotic bone, the volume of soft tissue, and bone mineral density (BMD) were calculated. The linear correlations between the aforementioned indicators and the disease duration were estimated. The logistic regression analysis was conducted to evaluate the correlation of these indicators with the radiographic progression. Receiver operating characteristic (ROC) analysis was used to evaluate these indicators’ prediction performance. Results The volume of sclerotic bone and the BMD grew with disease duration, but the volume of soft tissue decrease. The logistic regression analysis found that the volume of sclerotic bone and the BMD were statistically associated with radiographic progression. The ROC analysis found that the regression model, which integrated the volume of sclerotic bone and the BMD, had satisfactory performance in predicting radiographic progression. Conclusion The present study suggested a dynamic evolution of the osseous structure and a dynamic variation trend of the collapse risk in ONFH. The volume of sclerotic bone and the BMD might serve as further prognostic indicators when estimating the collapse risk.