Imaging manifestations of juvenile hyaline fibromatosis: A case report and literature review

Objective: Juvenile hyaline fibromatosis (JHF) is an autosomal recessive condition caused by a mutation in capillary morphogenesis gene 2 (CMG2) on chromosome 4q21. JHF is an extremely rare genetic disorder, and fewer than a hundred cases have been reported worldwide. In this case report, the clinical features, histopathological features and imaging manifestations of a case of JHF are presented. We present imaging manifestations of one case of JHF to deepen the radiologist’s understanding of this condition. The histopathological feature of JHF is hyaline degeneration involving skeletal muscle. Therefore, the lesion has a slightly high density on CT imaging, iso- or hypointense signal on T1WI and hypointense signal on T2WI. The boundary between the lesion and skeletal muscle is unclear. Methods: An 8-year-old male (case 1) was examined in our department with a complaint of multiple masses on the head, neck and back in 2021. The boy was the only child of his parents and was delivered at 40 weeks gestation by caesarean section. His parents were nonconsanguineous. Results : JHF displays multiple slowly or rapidly growing subcutaneous nodules. The imaging manifestations can reflect histopathological components, including nodular connective tissue and amorphous, partially calcified hyaline material.

Intraventricular tuberculosis abscess in an immunocompromised patient: clinical vignette

Tuberculosis is caused by Mycobacterium tuberculosis. Tuberculosis of the central nervous system is common and manifestations include meningeal and intraparenchymal diseases. However, intraventricular tuberculous abscess is a rare manifestation of intracranial tuberculous infection. We present a case of an immunocompromised female patient with high-grade fever and signs of meningism. The computed tomography and magnetic resonance imaging (MRI) of the brain showed hydrocephalus with rim-enhancing lesion in the right lateral ventricle. The MRI demonstrated a hypointense signal on T1-weighted imaging, hyperintense signal on T2-weighted imaging, and mild restricted diffusion in diffusion-weighted imaging. She underwent emergency external ventricular drainage and frank pus was drained. Diagnosis of tuberculosis was made via polymerase chain reaction analysis and culture. Understanding the intracranial manifestation of neurotuberculosis is imperative to arrive at the diagnosis correctly and ensure prompt treatment.

Dark Cartilage Lesions in the Knee: MRI Appearance and Clinical Significance

Early investigations into the magnetic resonance imaging (MRI) appearance of articular cartilage imaging relied on assessment of the morphology, with subsequent investigators reporting identifying increased T2 signal intensity, bright signal, in degenerated cartilage. The cartilage “black line sign” is a finding that has recently been described in the radiology literature to characterize cartilage pathology. This sign refers to a focal linear hypointense signal within articular cartilage that is oriented perpendicular to the subchondral bone on T2-weighted MRI. The diagnostic significance and clinical relevance of this sign is debated. Since its first description, several papers have further delineated the etiology, prevalence, and clinical relevance of these and other dark cartilage abnormalities. The intent of this article is to summarize these findings, with hopes of bringing to light the importance of dark cartilage lesions and their clinical implication in the world of knee surgery. We will briefly discuss the most probable etiologies of dark cartilage abnormalities and the major factors determining the unique signal intensity. The described anatomical patterns of this finding, the clinical importance, potential mimics, and current treatment recommendations will be reviewed.

Intra-articular venous malformations of the knee: a diagnostic challenge

Background Intra-articular venous malformations (IAVM) are rare benign vascular anomalies that usually affect young patients and most common locate in the knee. The terminology of these lesions is still ill-defined, as they are often termed in the literature as synovial hemangiomas. Early diagnosis can be difficult, because they usually present with nonspecific clinical manifestations that are similar those of other rheumatic diseases, especially juvenile idiopathic arthritis (JIA). Case series We conducted a retrospective analysis of five pediatric patients admitted to our units for recurrent swelling of the knee, and compared their characteristics with those of literature reports. The average age at first symptom and time from onset to diagnosis was 3.9 years (range 18 months-7 years) and 3.5 years (range 1-7 years), respectively. In our patients, an initial misdiagnosis of JIA, bleeding disorder or traumatic arthropathy was made. On MRI imaging, the features of the lesion were similar in all patients, and were marked by isointense-to-hypointense signal in T1-weighted images, and hyperintense signal in T2-weighted images. When performed, arthrocentesis led to aspiration of bloody fluid. The diagnosis was confirmed with a biopsy and histopathologic assessment in all patients. Open surgery enabled complete excision of the mass and was followed by stable remission over time in all cases. Conclusions Our report highlights the challenges that may be posed by the detection of knee IAVM and the frequent long delay between onset of symptoms and diagnosis. The key elements for early recognition include careful assessment of patient history, demonstration of bloody fluid on arthrocentesis, and proper interpretation of MRI scanning.

T2-FLAIR mismatch sign for diagnosis of 1p19q non-codeleted or ATRX mutant astrocytoma

Aims The World Health Organisation (WHO) classification of adult gliomas has undergone significant revision in recent years, with current emphasis on the role of the molecular biomarkers IDH, 1p19q, ATRX, and p53 for classification of glioblastoma, astrocytoma, and oligodendroglioma. When correctly applied the T2-FLAIR mismatch sign is reported to have 100% specificity for WHO grade II or III IDH mutant 1p19q non-codeleted astrocytoma. We sought to verify this classic imaging-molecular correlate in our cohort at a single tertiary level neurosurgical referral centre in the United Kingdom. Method Data were gathered by searching the histopathology database for cases between 2014 and 2019 containing the keywords ‘IDH Mutant’ AND ‘Astrocytoma’ or ‘Glioblastoma’ or ‘Oligodendroglioma’ in the report. Inclusion criteria: Biopsy/resection proven IDH mutant tumours in adults (age >17). A strict application of the T2-FLAIR mismatch sign was used when evaluating MRI. Native T2 signal was required to be homogenous or near homogenous, with hypointense signal on T2 weighted FLAIR except for a hyperintense peripheral rim. In addition, the T2-FLAIR mismatch sign was not applied to tumours showing any unequivocal contrast enhancement or macrocystic change. Results 66/185 cases were excluded for reasons of insufficient imaging, duplication, 1p19q partial deletion/unknown + ATRX wild type/unknown, IDH wild type/negative, Grade IV histology. 119 cases fit the inclusion criteria, all IDH positive. Group 1 comprised 49 (39%) 1p19q codeleted tumours, or oligodendrogliomas. ATRX was wild type (78%), unknown (18%), or mutated (<1%). Group 2 comprised 37 (29%) 1p19q non-codeleted tumours, or astrocytomas. ATRX was mutated (70%), unknown (22%), wild type (5%), or equivocal (3%). Group 3 comprised 41 (32%) 1p19q unknown tumours, all ATRX mutated, p53 expressed (83%). When p53 status was unaltered/equivocal, microscopy was convincingly astrocytic. Groups 2 and 3 comprised the astrocytomas (61%). T2-FLAIR mismatch was positive in 5 1p19q non-codeleted astrocytomas, 5 1p19q unknown ATRX mutant astrocytomas, and no 1p19q co-deleted oligodendrogliomas. Test sensitivity and specificity was 14% and 100% for 1p19q non-codeletion, 13% and 100% for ATRX mutation. Conclusion Although relatively uncommon, when present and correctly applied we confirm 100% specificity of the T2-FLAIR mismatch sign for IDH mutant 1p19q non-codeleted astrocytoma. However, if 1p19q status is unknown, clear astrocytic histology and ATRX mutation and/or p53 overexpression is also considered sufficient to diagnose astrocytoma. When 1p19q status is unavailable we also report 100% specificity of T2-FLAIR mismatch for ATRX mutated astrocytomas. T2-FLAIR mismatch was not observed in any 1p19q codeleted oligodendrogliomas or ATRX wild type tumours. More accurate methods of non-invasive glioma diagnosis will help improve neurohistopathological correlation, prognostication, and guide the tempo of the pre-operative planning phase.

Joint ex vivo MRI and histology detect iron-rich cortical gliosis in Tau and TDP-43 proteinopathies

Frontotemporal lobar degeneration (FTLD) is a heterogeneous spectrum of age-associated neurodegenerative diseases that include two main pathologic categories of tau (FTLD-Tau) and TDP-43 (FTLD-TDP) proteinopathies. These distinct proteinopathies are often clinically indistinguishable during life, posing a major obstacle for diagnosis and emerging therapeutic trials tailored to disease-specific mechanisms. Moreover, MRI-derived measures have had limited success to date discriminating between FTLD-Tau or FTLD-TDP. T2*-weighted (T2*w) ex vivo MRI has previously been shown to be sensitive to non-heme iron in healthy intracortical lamination and myelin, and to pathological iron deposits in amyloid-beta plaques and activated microglia in Alzheimer's disease (AD). However, an integrated, ex vivo MRI and histopathology approach is understudied in FTLD. We apply joint, whole-hemisphere ex vivo MRI at 7T and histopathology to the study autopsy-confirmed FTLD-Tau (n=3) and FTLD-TDP (n=2), relative to an AD disease-control brain with antemortem clinical symptoms of frontotemporal dementia and an age-matched healthy control. We detect distinct laminar patterns of novel iron-laden glial pathology in both FTLD-Tau and FTLD-TDP brains. We find iron-positive ameboid and hypertrophic microglia and astrocytes largely in deeper GM and adjacent WM in FTLD-Tau. In contrast, FTLD-TDP presents prominent superficial cortical layer iron reactivity in astrocytic processes enveloping small blood vessels with limited involvement of adjacent WM, as well as more diffuse distribution of punctate iron-rich dystrophic microglial processes across all GM lamina. This integrated MRI/histopathology approach reveals ex vivo MRI features that are consistent with these pathological observations distinguishing FTLD-Tau and FTLD-TDP, including prominent irregular hypointense signal in deeper cortex in FTLD-Tau whereas FTLD-TDP showed upper cortical layer hypointense bands and diffuse cortical speckling. Moreover, differences in adjacent WM degeneration and iron-rich gliosis on histology between FTLD-Tau and FTLD-TDP were also readily apparent on MRI as hyperintense signal and irregular areas of hypointensity, respectively that were more prominent in FTLD-Tau compared to FTLD-TDP. These unique histopathological and radiographic features were distinct from HC and AD brains, suggesting that iron-sensitive T2*w MRI, adapted to in vivo application at sufficient resolution, may offer an opportunity to improve antemortem diagnosis of FTLD proteinopathies using tissue-validated methods.

Secondary Chiari malformation due to enlarged spinal arachnoid villi–like structure: illustrative case

BACKGROUNDSecondary Chiari malformation can be caused by various disorders associated with cerebrospinal fluid (CSF) leakage at the spinal level. In this report, the authors describe a rare case of secondary Chiari malformation caused by excessive CSF absorption through the enlarged spinal arachnoid villi–like structure.OBSERVATIONSA 20-year-old woman presented with progressive severe headache and posterior neck pain. Magnetic resonance imaging showed tonsillar herniation and decreased subarachnoid space around the spinal cord. A hypointense signal area was observed in the ventral spinal canal on a T2-weighted image. An axial image revealed multiple small, arachnoid cyst–like structures at the right T1 nerve root sleeve. Direct surgery revealed that the cyst-like structures were continuous with the arachnoid membrane and protruded into the abnormally large epidural venous sinus. The cyst-like structures were resected, and the dural sleeve was repaired using fascia. The patient showed good improvement of symptoms after surgery.LESSONSExcessive CSF absorption through the enlarged spinal arachnoid villi–like structure can cause secondary Chiari malformation. Neurosurgeons should be aware of this unusual mechanism of CSF leakage. Simple posterior fossa decompression will be ineffective or even harmful.

Imaging of endometrial osseous metaplasia—an uncommon but treatable cause of infertility

Background Endometrial osseous metaplasia (EOM) is an uncommon condition characterised by metaplastic transformation of endometrial tissue into osteoblasts (mature or immature bone in the endometrium). Etiopathogenesis of EOM is explained by multiple putative mechanisms like dystrophic calcification, metaplastic ossification, retained foetal bones after abortions and genito-urinary tuberculosis. EOM has varied clinical presentation ranging from patient being asymptomatic to secondary infertility. Although hysteroscopy is the gold standard for its diagnosis and treatment, non-invasive imaging comprising chiefly of ultrasonography (USG) is increasingly becoming the mainstay of diagnosis. We aim to present the imaging findings in EOM to acquaint radiologists and gynaecologists with this condition to avert misdiagnosis of this uncommon yet treatable cause of infertility. Results Mean age of patients was 31.4 ± 5.4 (S.D) years. USG revealed linear or tubular densely echogenic endometrium with posterior acoustic shadowing in all the 14 patients. MRI in 3 patients revealed diffuse or patchy areas of T1W and T2W hypointense signal intensity with unilateral (n = 2) and bilateral (n = 1) ovarian cysts. One patient who underwent CT scan revealed dense endometrial calcification. Histopathologic examination (HPE) revealed lamellar (n = 6) or trabecular (n = 4) bone within endometrium (EOM) and inflammatory cells with calcification in four patients (calcific endometritis). Twelve patients conceived after dilatation and curettage within 15 months. Conclusion Familiarity with the imaging appearances of EOM is indispensable to clinch this diagnosis and avert misdiagnosis of this rare but potentially treatable cause of infertility. USG is usually sufficient for diagnosis. MRI and CT are only supplementary tools in difficult clinical scenarios.

Imaging Features and Floating-Ice Sign of Primary Lymphoma of the Bone

Background: The imaging presentation of primary bone lymphoma is unclear. Objectives: The present study aimed to investigate the imaging presentations of primary bone lymphoma especially a specific “floating-ice” sign. Patients and Methods: Forty one patients with primary bone lymphoma confirmed by pathology with 27 males and 14 females and an age range of 2 - 76 (mean = 40) years were enrolled. The clinical and imaging data were analyzed. Results: The tumor involved long bones in 17 cases, flat bones in 12, spine in eight and irregular bones in four cases. The imaging presentations were divided into five types: infiltrative type in nine cases (22%), osteolytic in 14 cases (34.1%), osteosclerotic in four cases (9.8%), mixed in 11 cases (26.8%) including four cases with a “floating-ice” sign and cystic in three cases (7.3%). In plain radiography, only three of four long bone lesions in children had a varying degree of periosteal reaction. Among 20 cases with CT scanning, sixteen had soft tissue masses, seventeen had ill-defined margins, and three had well-defined margins with sclerotic rims. Among twelve patients with MRI, ten had soft tissue masses with well-defined margins. MRI demonstrated a greater extent of lesion than CT. In MRI T1 weighted image (T1 WI), isointense signal was seen in three cases, hypointense signal in five and mixed signal in four. In T2 WI, isointense and hypointense signal was detected in five cases, hyperintense signal in three and mixed hyperintense signal in four. Conclusion: Primary bone lymphoma occurs most frequently in long and flat bones as infiltrative osteolytic destruction, and combined plain radiographs, CT and MRI help obtain a correct diagnosis.

Calcific Tendinitis of the Supraspinatus Tendon in an Infant

Calcific tendinitis of the supraspinatus tendon in adults is common, but it is extremely rare in children. This report presents an unusual case of a 2-year-old boy with calcific tendinitis of the supraspinatus tendon. A mother brought her 2-year-old son to our hospital with a fever and severe left shoulder pain. Examination revealed a temperature of 38.6°C accompanied by a swollen shoulder with extreme pain and restricted movement. The radiographs of his left shoulder showed a large radio-opacity in the subacrominal region, and magnetic resonance imaging showed an elongated T1 and T2 hypointense signal above the supraspinatus tendon. Although these images were suggestive of calcific tendinitis of the supraspinatus tendon, we performed an open biopsy and resection in order to differentiate between a suspected diagnosis of calcific tendinitis, which is incredibly rare within pediatric patients, and infection or a soft tissue tumor. Finally, calcific tendinitis of the supraspinatus tendon was diagnosed by pathologic experiment and successfully treated, with complete resolution of pain and movement. Because only four other pediatric cases of calcific tendinitis of the supraspinatus tendon have ever been reported, there is a lack of information on the diagnostic process, management, and treatment of such a condition in young patients. Calcific tendinitis of the supraspinatus tendon still should be considered when encountering cases with typical findings even if the patient is a child.