Extra-axial chordoma of the thumb: Report of a rare case with clinicopathologic and molecular analysis.

Chordoma is a very rare malignant tumor, with a phenotype that recapitulates notochord, and is chiefly located in the axial skeleton with only few cases reported in the extra-axial skeleton and soft tissues. The diagnosis can be challenging for both clinicians, radiologists and pathologists because of the rarity of tumor, its unspecific radiological pattern and histomorphological similarities to other tumors like extra-skeletal myxoid chondrosarcoma, soft tissue myoepithelioma and metastatic adenocarcinomas, more so on small biopsies. We present a case of a recurrent extra-axial chordoma with a prominent soft tissue component in the left thumb around proximal phalanx of an 80-year-old man, with detailed report of the histopathological, imaging and most importantly molecular features, which are in conformity with the typical profile of notochordal neoplasms. To the best of our knowledge, we report the first DNA-methylation- and the copy number variation analysis of an extra-axial chordoma with a very rare localization, thumb. With this case study we try to give a better understanding of tumor's specification, lessen the diagnostic confusion by highlighting its extra-axial occurrence, and more importantly present substantial molecular data, which might help in providing more therapeutic opportunities in the future.

Hybrid FDG PET/MRI vs. FDG PET and CT in patients with suspected dementia - A comparison of diagnostic yield and propagated influence on clinical diagnosis and patient management.

BACKGROUND: Both 18F-fluoro-deoxy-glucose (FDG) positron emission tomography (PET), computed tomography (CT) and magnetic resonance imaging (MRI) are routinely used in the evaluation of memory clinic patients. Hybrid PET/MR systems now allow simultaneous PET and MRI imaging within the duration of the PET emission scan. PURPOSE: To compare the diagnostic yield of PET/MRI using an abbreviated MR protocol with that of separate PET and CT in a mixed memory clinic population, and the propagated influences on clinical diagnosis and patient management. MATERIAL AND METHODS: Consecutive memory clinic patients (n = 78) undergoing both CT and hybrid FDG PET/MRI scans were identified retrospectively. MRI and CT were separately evaluated for vascular and structural pathology. PET scans were classified according to the presence of neurodegenerative or vascular disease using CT or MRI, respectively, for anatomical guiding. A memory clinic expert assessed the clinical impact of the additional findings and/or change of PET classification achieved by MRI anatomical guiding as compared to CT guiding. RESULTS: MRI lead to significantly higher Fazekas scores, higher medial temporal and global cortical atrophy scores, and identified more patients with infarcts (28 vs 8, p<0.001) compared to CT. MRI changed PET classification in 13 (17%) patients. Addition of MRI to CT had minor clinical impact in 4/78 (5%) and major clinical impact in 13/78 (17%) of patients. CONCLUSION: The study demonstrates the capabilities of PET/MRI systems for routine clinical imaging of memory clinic patients, and that even an abbreviated hybrid PET/MRI protocol provides significant additional information influencing clinical diagnosis and patient management in a substantial fraction of patients when compared to separate PET and CT.

Early Clinical and Radiological Experience with a Ceramic Bone Graft Substitute in the Treatment of Benign and Borderline Bone Lesions.

Substitutes for bone grafts experience increasing popularity, but the need for defect-filling following simple curettage of benign bone lesions is controversial. In this study, we wish to objectively report the radiological changes following bone defect-filling using a composite ceramic bone graft substitute, as well as the clinical results and complications. We evaluated 35 surgically treated benign bone lesions with subsequent defect-filling using two variants of a composite ceramic bone graft substitute (CERAMENT|BONE VOID FILLER or CERAMENT|G, BONESUPPORT AB, SWEDEN). After one year, a normal cortical thickness surrounding the defect was seen in approximately 80% of patients. Inside the defect-cavity, an almost complete product-resorption was seen after one year. The most common complication was a post-operative inflammatory soft-tissue reaction, seen in 7 patients (20%), which resolved without further treatment, although short-term antibiotic treatment was initiated at a local hospital in 6 patients, due to suspected wound infection. In summary, cortical thickness most commonly normalizes after bone tumor removal and filling of the bone defect using this particular composite ceramic bone graft substitute. The ceramic substitute undergoes resorption, which causes progressive changes in the radiological appearance inside the bone defect.