Similar Radiological Findings Research Articles

COMPARISON OF CLINICAL CHARACTERISTICS OF PATIENTS HOSPITALIZED DUE TO SARS-COV-2, INFLUENZA AND RESPIRATORY SYNCYTIAL VIRUS PNEUMONIA

OBJECTIVE: Influenza, respiratory syncytial virus (RSV), and severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection are agents that spread through droplets, have similar symptoms and radiological findings, and can cause respiratory failure. This study was conducted to compare the clinical features and mortality rates of patients with novel coronavirus disease (COVID-19), influenza, and respiratory syncytial virus pneumonia. MATERIAL AND METHODS: A total of 182 patients who were hospitalized at Baskent University Medical Faculty Hospital due to COVID-19, influenza, and RSV were included in the study. Patients were grouped according to their clinical status. Demographic characteristics, comorbidities, laboratory and radiological findings, respiratory support treatments and mortality rates of the patients were recorded and compared between the groups. RESULTS: The mean age was 69.4±7 years in the COVID-19 group (n:115), 72.9±17.1 years in the influenza group (n:33), and 66.5±22.4 years in the RSV group (n:34). There was no difference in age between the groups (p=0.305). The hospitalization rate was higher for male patients in the COVID-19 group (p=0.036). There was no difference between the groups in terms of comorbidities (p>0.05). There was no difference in mortality rates between the COVID-19, RSV, and influenza patient groups (p=0.260). CONCLUSIONS: Viral infections with pulmonary involvement require special attention because they can have a poor clinical course. The severity of the clinical course of COVID-19 pneumonia, which causes deaths in the current century, is not different from the clinical course of viral infections such as influenza and RSV.

Solitary Bone Cyst and Aneurysmal Bone Cyst: Perplexing Pseudocysts of the Jaws

Pseudocysts of the jaws include two very significant lesions – Solitary bone cyst (SBC) and Aneurysmal bone cyst (ABC). Both these cysts have very similar clinical and radiological findings. Histopathology aids in differentiating the two pathologies, with MRI findings offering confirmatory diagnosis of ABC. Differentiating between the two cysts and establishing a definitive diagnosis cannot be over emphasised as prognosis depends on the correct treatment modality after the diagnosis. A lot of updates with regards to the treatment of these cysts in long bones is available, with the same lacking in the cysts of the jaws. This probably could be due to the relative rarity of these cysts in the jaws. This article aims to address the various aspects of these two enigmatic pseudocysts of the jaws. Keywords: Pseudocysts, Solitary Bone Cyst, Aneurysmal Bone Cyst, Pathogenesis, Hemorrhage, Head & Neck, Oral

Diffusion tensor imaging and voxel-based morphometry in differentiating multiple sclerosis and its mimics

BackgroundThe discrimination between multiple sclerosis (MS) and other white matter lesions in adults is still problematic as multiple diseases have similar clinical and radiological findings, especially at the disease onset. This case–control study aimed to evaluate the efficacy of diffusion tensor imaging (DTI) and brain morphometry in the differentiation between adult MS and its magnetic resonance imaging (MRI) mimics.MethodsFifty-eight patients (49 women and 9 men; mean age 35.74 ± 11.86 years, range 18–50 years) with clinically suspected MS and age- and sex-matched fifteen healthy subjects were included. All study subjects underwent MRI using 3D FLAIR, 3D T1 MPRAGE, axial T2WI fast spin echo, and DTI sequences. The included patients were classified into MS and mimics groups according to MC Donald’s criteria 2017. Image post-processing using the region of interest (ROI) analysis for DTI parameters and automated voxel brain morphometry and segmentation was done for all study groups. Statistical comparison between the two patient groups and between them and the control group was performed regarding DTI indices (fractional anisotropy [FA], mean diffusivity [MD], and relative anisotropy [RA]) and brain morphometry parameters (including white matter volume (WMV), grey matter volume (GMV), cerebrospinal fluid volume (CSFV), T2 lesion load and deep grey matter volume).ResultsA statistically significant difference was observed between the MD, FA, and RA values of the patients and control groups. The MD values were significantly higher in the MS than in its mimics with a cut-off value of > 1.058 × 10−3 mm2/s (p < 0.001). Compared to the mimics group, the MS patients showed significantly lower WMV (33.31 ± 4.40 versus 35.71 ± 4.58; p = 0.047) and higher CSFV (16.38 ± 5.93 versus 13.06 ± 3.09; p = 0.012) with no significant difference regarding the GMV.ConclusionsMD analysis of DTI, WMV, and CSFV are useful quantitative measurements in confirming the diagnosis of MS and differentiating it from its imaging mimics.

Clinical and radiological outcomes of open reduction alone versus open reduction with pelvic osteotomy for developmental dysplasia of the hip in children over 1.5 years of age.

Developmental dysplasia of the hip (DDH) is commonly addressed through surgical intervention, usually performed in a specialized tertiary care facility. The purpose of this study was to evaluate the surgical outcomes in patients with DDH who had open reduction alone or in conjunction with bone surgery at our facility. We retrospectively reviewed the medical records of patients with DDH, categorizing them into two groups: Group OR underwent open reduction (OR) alone, and group ORBO underwent OR in conjunction with femoral or pelvic osteotomies. The modified McKay classification was used to evaluate clinical outcomes, and the Severin classification was used to evaluate radiological outcomes. Avascular necrosis and other postoperative issues were observed. Our cohort consisted of 66 patients (76 hips), with a mean age at surgery of 1.8±2.6 and a follow-up period ranging from one to three years. Clinically, 48 out of 66 patients achieved satisfactory outcomes, and radiologically, 47 patients were classified as satisfactory. Although there was no statistically significant difference in the radiological outcome (P=0.85), more patients in the OR group than in the ORBO group (P=0.05) had better outcomes. Avascular necrosis (AVN) was observed in 23 hips (34.8%), with Grade I AVN being the most prevalent in 19 hips that underwent OR with bone surgery (63.2%). The occurrence of AVN was associated with poorer clinical and radiological outcomes (P=0.05). Overall, the DDH operation at our center had positive outcomes. The OR group showed better clinical outcomes despite similar radiological findings and AVN rates compared to the OR with bone surgery group. The presence of AVN was linked to poor clinical and radiological outcomes.

Supratentorial extra-axial anaplastic ependymoma: a rare case report.

Ependymomas are central nervous system tumors arising from the ependymal lining of the ventricle and spinal cord. Supratentorial extra-axial ependymomas are very rare, most commonly affecting the pediatric population and rarely in adults. The authors report a case of a 71-year-old female with a headache and blurred vision. An MRI scan revealed a lesion at the parafalcine region of the occipital lobe. A parieto-occipital craniotomy was performed. When the dura was opened during the operation, the extra-axially located, well-circumscribed, dirty yellow-white tumor dissected from the surrounding tissue was excised entirely by microdissection. Histopathological examination revealed supratentorial extra-axial anaplastic ependymoma. The patient received postoperative radiation therapy (54 Gray over 30 fractions). No recurrence of the tumor was observed during the 4-year follow-up. Supratentorial ependymomas at the extra-axial region are uncommon; extra-axial anaplastic ependymoma and meningiomas have similar radiological findings, such as a dural tail, subarachnoid plane, and diffuse enhancement after contrast injection. This close similarity might cause misdiagnoses. Total surgical resection was followed by adjuvant radiotherapy and close follow-up in the gold standard of the treatment. The authors report a rare case of anaplastic ependymomas located at the extra-axial region. Anaplastic tumors are prone to recurrence despite total resection and radiation therapy; hence, a close follow-up is warranted.

Step by Step: Radiologic Features of Pulmonary Vascular Disease Made Simple

“Pulmonary vascular disease” is a broad term that includes any condition that affects the blood vessels within the lungs. Most of these pathologies have similar radiologic findings, thus clinical and histopathologic complements are essential tools for an appropriate diagnosis. This article provides methodologic radiology guidelines to approach the diagnosis of the most frequent pathologies that involve pulmonary vascularity.

Subclinical high-resolution chest CT scan features in psoriasis

BackgroundAlthough psoriasis is considered a systemic disease, no clear association has been established between psoriasis and lung diseases. This study aims to detect and describe subclinical pulmonary involvement in psoriasis patients with various degrees of cutaneous manifestations. MethodsAdult psoriasis patients with no known active pulmonary disease or respiratory symptoms were screened for subclinical pulmonary manifestations and possible parenchymal changes using high-resolution computed tomography (HRCT) scan of the chest. Patients were classified according to the severity of skin manifestations. The clinical characteristics and radiographic findings of these patients were evaluated. ResultsFifty-nine patients with psoriasis were included, among which 47 (79.7%) had abnormal HRCT scan features. Micronodules were the most common detected lung lesions (66.1%), followed by nonspecific interstitial changes (32.2%), including pleuro-parenchymal band/atelectasis, scarring, and focal ground-glass opacities. Other HRCT findings included emphysematous changes and calcified granulomas. Abnormal HRCT findings correlated with older age and duration of psoriasis but not with the severity of skin manifestations. ConclusionsMicronodules and minor focal nonspecific interstitial changes were the most detected lung alterations in patients with psoriasis. These findings of the pilot study highlight a possible pulmonary involvement in patients with psoriasis. Larger multicenter studies are needed to clarify these findings further. LimitationsA major limitation of the study, is the lack of a control group with similar radiologic findings of different conditions done in the same geographical region.

An inception-based deep multiparametric net to classify clinical significance MRI regions of prostate cancer

Objective. Multi-parametric magnetic resonance imaging (MP-MRI) has played an important role in prostate cancer diagnosis. Nevertheless, in the clinical routine, these sequences are principally analyzed from expert observations, which introduces an intrinsic variability in the diagnosis. Even worse, the isolated study of these MRI sequences trends to false positive detection due to other diseases that share similar radiological findings. Hence, the main objective of this study was to design, propose and validate a deep multimodal learning framework to support MRI-based prostate cancer diagnosis using cross-correlation modules that fuse MRI regions, coded from independent MRI parameter branches. Approach. This work introduces a multimodal scheme that integrates MP-MRI sequences and allows to characterize prostate lesions related to cancer disease. For doing so, potential 3D regions were extracted around expert annotations over different prostate zones. Then, a convolutional representation was obtained from each evaluated sequence, allowing a rich and hierarchical deep representation. Each convolutional branch representation was integrated following a special inception-like module. This module allows a redundant non-linear integration that preserves textural spatial lesion features and could obtain higher levels of representation. Main results. This strategy enhances micro-circulation, morphological, and cellular density features, which thereafter are integrated according to an inception late fusion strategy, leading to a better differentiation of prostate cancer lesions. The proposed strategy achieved a ROC-AUC of 0.82 over the PROSTATEx dataset by fusing regions of K trans and apparent diffusion coefficient (ADC) maps coded from DWI-MRI. Significance. This study conducted an evaluation about how MP-MRI parameters can be fused, through a deep learning representation, exploiting spatial correlations among multiple lesion observations. The strategy, from a multimodal representation, learns branches representations to exploit radio-logical findings from ADC and K trans. Besides, the proposed strategy is very compact (151 630 trainable parameters). Hence, the methodology is very fast in training (3 s for an epoch of 320 samples), being potentially applicable in clinical scenarios.

PARTIAL ANOMALOUS PULMONARY VENOUS CONNECTION DIAGNOSED AFTER CENTRAL VENOUS CATHETER PLACEMENT

PARTIAL ANOMALOUS PULMONARY VENOUS CONNECTION DIAGNOSED AFTER CENTRAL VENOUS CATHETER PLACEMENT

Radiological Characteristics of Low-Grade Lytic Spondylolisthesis: Similarity to Dysplastic Spondylolisthesis.

Retrospective case-control study. This study aimed to analyze the etiology of low-grade lytic spondylolisthesis based on the radiologic features of the vertebra. According to the Marchetti-Bartolozzi classification scheme, high-grade lytic spondylolisthesis (Meyerding grade 3-5) is classified as dysplastic. However, determination of the etiology for low-grade lytic spondylolisthesis as developmental or traumatic remains controversial. Patients admitted and treated for one-level (L4/5 or L5/S1) low-grade spondylolisthesis were included in the study. A total of 135 patients were divided into the degenerative or lytic spondylolisthesis groups according to their condition (81 patients [degenerative group] vs. 54 patients [lytic group]). To assess the level of similarity in the radiological findings between low-grade lytic spondylolisthesis and dysplastic spondylolisthesis, the pedicle diameters and vertebral heights of the L4 and L5 vertebrae were measured on computed tomography images. Measurements were then converted to each vertebra's ratio to reduce confounding factors among individuals. The affected vertebra had a smaller sagittal pedicle diameter/transverse pedicle diameter ratio in the low-grade lytic spondylolisthesis group compared to the degenerative group, and the posterior vertebral height/anterior vertebral height ratio of L5 was smaller in the L5/S1 lytic spondylolisthesis group compared to the degenerative spondylolisthesis group. Low-grade lytic spondylolisthesis and dysplastic spondylolisthesis demonstrated similar radiological findings. Hence, surgeons should be attentive to the morphology of the vertebral body and posterior column during preoperative planning for the treatment of low-grade lytic spondylolisthesis.

Contrast-enhanced spectral mammographic findings of phyllodes tumor of the breast

BackgroundPhyllodes tumors of breast are rare fibroepithelial neoplasms. They have similar radiological findings with fibroadenomas. While fibroadenomas are benign lesions, phyllodes tumors may have malignant potential. Therefore, any imaging findings to differentiate fibroadenoma from phyllodes tumor are valuable.Case presentationA 51-year-old female patient was admitted to our clinic with the complaint of a palpable mass. Tru-Cut biopsy resulted as phyllodes tumor, and excision was recommended. However, the patient neglected herself during the COVID-19 pandemic, and 20 months later, she presented with a huge and complex mass. On CESM imaging, cystic areas and clefts were identified. The case was diagnosed as borderline phyllodes tumor.ConclusionsAlthough MRI findings of phyllodes tumor are well known and reported many times, there is no information about CESM findings of this tumor in literature. Bubbly appearance on CESM is useful finding in the diagnosis of phyllodes tumor of breast.

Primary Intrarenal neuroblastoma in a 5-month-Old infant: A diagnostic dilemma

Abdominal masses in the pediatric population are usually retroperitoneal in location and 50% are renal in origin. In less than six months of age, the most common renal tumor is mesoblastic nephrons and the frequency of t Wilms' tumor increases after that. Neuroblastoma is the most common retroperitoneal tumor in those less than two years of age and commonly adrenal in origin. Its diagnosis is difficult and challenging, since both Wilms' tumor and intrarenal neuroblastoma may present with the similar clinical and radiological findings. It is crucial to differentiate between them given the different treatment modalities and clinical outcomes.

Chondrosarcoma and Chordoma of the Skull Base and Spine: Implication of Tumor Location on Patient Survival

Chondrosarcoma and chordoma are often grouped together because of their similar anatomic locations, clinical presentations, histopathological and radiological findings, and growth patterns. In the present study, we investigated the clinical and prognostic differences of chondrosarcomas and chordomas of the skull base and spine. We accessed the Surveillance, Epidemiology, and End Results database to search for patients from 2000 to 2018 with chondrosarcomas and chordomas of the skull base and spine for inclusion in the present study. We included 1346 and 1536 cases of chondrosarcoma and chordoma for analysis, respectively. Chondrosarcomas of the cranial base and spine were seen in younger patients and were associated with a larger tumor size compared with chordomas. Among the tumors of the skull base, chondrosarcomas were more common in women, with a male predominance found for chordomas. We also observed a male predilection for both spinal chondrosarcomas and chordomas. Distinct metastatic patterns were found for chondrosarcomas versus chordomas, and spinal chondrosarcomas showed a greater risk of distant metastases at presentation compared with spinal chordomas. Cranial base chondrosarcomas were associated with superior outcomes compared with chordomas. However, we demonstrated an opposite survival pattern for spinal chondrosarcomas and chordomas. Chondrosarcomas and chordomas have divergent clinical manifestations and prognoses depending on the anatomic location.

MicroRNA-profiling of miR-371~373- and miR-302/367-clusters in serum and cerebrospinal fluid identify patients with intracranial germ cell tumors

PurposeIntracranial germ cell tumors (iGCT) comprise germinoma and non-germinoma. Their diagnosis predominantly relies on biopsy as only one-fifth of patients present with elevated biomarkers (AFP/ß-HCG) in serum or cerebrospinal fluid (CSF). MicroRNAs (miR/miRNA) have emerged as non-invasive biomarkers in extracranial GCT and may potentially facilitate non-invasive diagnosis in iGCT.MethodsWe analyzed eight miRNAs in serum and CSF from the miR-371~373- and miR-302/367-clusters and four miRNAs differentially expressed in iGCT tissue (miR-142-5p/miR-146a-5p/miR-335-5p/miR-654-3p) from eight iGCT patients (age 10–33 years) and 12 control subjects by pre-amplified RT-qPCR. MiR-30b-5p (serum) and miR-204-5p (CSF) acted as reference genes. ΔCt-values were expressed as 2^{{ - Delta Delta C_{{text{t}}} }} after standardization against controls.ResultsBetween iGCT and control patients’ serum ΔCt-values of miR-371a-3p (p = 0.0159), miR-372-3p (p= 0.0095, miR-367 (p = 0.0190), miR-302a (p = 0.0381) and miR-302d-3p (p = 0.0159) differed significantly. Discriminatory pattern in CSF was similar to serum as miR-371a (p = 0.0286), miR-372-3p (p = 0.0028), miR-367-3p (p = 0.0167) and miR-302d-3p (p = 0.0061) distinguished between patients and controls. Abundant 2^{{ - Delta Delta C_{{text{t}}} }} levels of each of these miRNAs were found across all serum and CSF samples including biomarker-negative patients.ConclusionWith the largest data set so far, we underline the suitability of miR-371a, miR-372, miR-367 and miR-302d in serum and CSF for diagnosis of iGCT, particularly in biomarker-negative germinoma. Diagnosis of iGCT by miRNA analysis is a feasible and valid approach, particularly as serum can be readily obtained by a less invasive procedure. MiRNA analysis may discriminate iGCT from other tumors with similar radiological findings and may allow to monitor response to therapy as well as early relapse during follow-up.

Clinical, radiological and pathological features of idiopathic and secondary interstitial pneumonia with pleuroparenchymal fibroelastosis in patients undergoing lung transplantation.

Idiopathic pleuroparenchymal fibroelastosis (PPFE) is a rare type of idiopathic interstitial pneumonia, and pathological PPFE is also observed in patients with secondary interstitial pneumonia. This study aimed to evaluate the pathological findings associated with radiological PPFE-like lesions and the clinical and morphological features of patients with pathological PPFE. We retrospectively reviewed the pathology of the explanted lungs from 59 lung transplant recipients with radiological PPFE-like lesions. Pathological PPFE lesions were identified in 14 patients with idiopathic disease and in 12 patients with secondary disease. Pathological PPFE was associated with previous pneumothorax, volume loss in the upper lobes, and a flattened chest. Patients with idiopathic disease and those with secondary disease with pathological PPFE had similar clinical, radiological and pathological findings, whereas fibroblastic foci were more common in patients with idiopathic disease, and patients with secondary disease more frequently showed alveolar septal thickening with elastosis or fibrosis. Post-transplantation survival did not differ between patients with idiopathic and secondary disease with pathological PPFE (log-rank; P = 0.57) and was similar between patients with idiopathic disease with pathological PPFE and those with idiopathic pulmonary fibrosis (IPF) (log-rank; P = 0.62). Not all patients with interstitial pneumonia with radiological PPFE-like lesions have pathological PPFE. Characteristic clinical features can suggest the presence of pathological PPFE, and idiopathic and secondary cases with pathological PPFE are similar except for fibroblastic foci in idiopathic cases and alveolar septal thickening with elastosis or fibrosis in secondary cases. Patients with pathological PPFE have a similar prognosis to those with IPF after transplantation.

Differential Diagnosis between Primary Intracranial Melanoma and Cerebral Cavernoma in Crohn’s Disease: A Case Report and Literature Review

Primary intracranial melanomas are rare, with a challenging diagnosis based only on clinical and imaging features. The authors described the case of an intracerebral right parieto-temporal melanoma mimicking a cavernoma in a patient affected by Crohn’s disease. A 67-year-old female patient with Crohn’s disease and small bowel stenosis was hospitalized for surgical removal of the terminal ileum and latero-lateral ileo-colic anastomosis. During postoperative week 1, the patient developed psychomotor agitation followed by altered consciousness. An urgent brain CT showed a right intracerebral parieto-temporal hemorrhage with intralesional calcifications. The patient underwent a decompressive craniectomy with hematoma drainage and a complete resection of the lesion. Histologic examination showed characteristics consistent with malignant melanoma. In patients with inflammatory bowel disease (IBD), the differential diagnosis between intracerebral melanoma and cavernoma may be challenging, considering the similar clinical and radiological findings. Thus, a comprehensive multidisciplinary approach is required to exclude the possible coexistence of such intracranial lesions.

Gradually progressive cholangiolocellular carcinoma: a case report

BackgroundCholangiolocellular carcinoma (CoCC) is a relatively rare primary liver tumor. We present a literature review and case report of a patient who presented with a slow-growing CoCC that was completely resected after a 5-year follow-up period.Case presentationThe patient was a 66-year-old man with a history of inflammatory thoracic and intra-abdominal pseudo-tumors. He was regularly followed up at our hospital for partial dilation of the pancreatic duct branch located in the body of the pancreas. Five years earlier, computed tomography (CT) demonstrated a small tumor in liver segment 4. Radiological findings were suggestive of hemangioma. Tumor size gradually increased during the 5-year follow-up period. CT scans showed that the tumor had progressed in size from 10 to 20 mm. Positron emission tomography CT revealed an accumulation of fluorodeoxyglucose (standardized uptake value max 5.3) at the tumor site. The tumor exhibited high intensity on T2-weighted and diffusion-weighted images of ethoxybenzyl magnetic resonance imaging. The tumor showed high intensity during the early phase but low intensity during the hepatobiliary phase. Tumor markers were within their respective normal ranges. Suspecting intrahepatic cholangiocarcinoma, left hepatectomy was performed. The tumor was diagnosed as CoCC based on pathological findings. The patient’s post-operative course was uneventful. The patient survived for a year, without any recurrence.ConclusionsIn cases dealing with small tumor sizes, it is difficult to distinguish between CoCC and hemangioma due to their similar radiological findings. Thus, it is important to consider the diagnosis of CoCC in small benign hepatic tumors. As such, follow-up radiological examination is recommended.

Radiologic Differentiation between Granulomatosis with Polyangiitis and Its Mimics Involving the Skull Base in Humans Using High-Resolution Magnetic Resonance Imaging.

Granulomatosis with polyangiitis (GPA) can involve the skull base or the Eustachian tubes. GPA is diagnosed on the basis of clinical manifestations and serological tests, although it is challenging to discriminate GPA from infectious processes driving skull base osteomyelitis (SBO) and malignant processes such as nasopharyngeal carcinoma (NPC). Moreover, current serological tests have a low sensitivity and cannot distinguish GPA from these other conditions. We hypothesized that certain MRI characteristics would differ significantly among conditions and aimed to evaluate whether the features could differentiate between GPA, SBO, and NPC involving the skull base. We retrospectively evaluated the MRI findings of patients with GPA, SBO, and NPC. We performed univariable logistic regression analyses to identify the predictive variables for differentiating between conditions and evaluated their diagnostic values. We showed, for the first time, that certain MRI findings significantly differed between patients with GPA and those with SBO or NPC, including the lesion morphology and extent, the apparent diffusion coefficient (ADC) values, the contrast enhancement patterns, the presence or absence of necrosis, and retropharyngeal lymphadenopathy. In conclusion, utilizing certain MRI features can improve the diagnostic performance of MRI by differentiating GPA with skull base involvement from other conditions with similar radiologic findings, including SBO and NPC, facilitating treatment plans and, thus, improving patient outcomes.

Prevalence of Fragile X-Associated Tremor/Ataxia Syndrome in Patients with Cerebellar Ataxia in Japan

The presence of fragile X mental retardation 1 (FMR1) premutation has been linked to patients with a certain type of cerebellar ataxia, the fragile X-associated tremor/ataxia syndrome (FXTAS). However, its prevalence in Japan has yet to be clarified. The aim of the present study is to determine the prevalence of FXTAS in Japanese patients with cerebellar ataxia and to describe their clinical characteristics. DNA samples were collected from 1328 Japanese patients with cerebellar ataxia, referred for genetic diagnosis. Among them, 995 patients with negative results for the most common spinocerebellar ataxia subtypes were screened for FMR1 premutation. Comprehensive clinical and radiological analyses were performed for the patients harbouring FMR1 premutation. We herein identified FMR1 premutation from one female and two male patients, who satisfied both clinical and radiological criteria of FXTAS (0.3%; 3/995) as well. Both male patients presented with high signal intensity of corticomedullary junction on diffusion-weighted magnetic resonance imaging, a finding comparable to that of neuronal intranuclear inclusion disease. The female patient mimicked multiple system atrophy in the early stages of her disease and developed aseptic meningitis with a suspected immune-mediated mechanism after the onset of FXTAS, which made her unique. Despite the lower prevalence rate in Japan than the previous reports in other countries, the present study emphasises the necessity to consider FXTAS with undiagnosed ataxia, regardless of men or women, particularly for those cases presenting with similar clinical and radiological findings with multiple system atrophy or neuronal intranuclear inclusion disease.

Orthokeratinized odontogenic cyst: A large series and comprehensive literature review with emphasis on synchronous multiple occurrence and neoplastic transformation

The objective of this study was to demonstrate the clinical, radiologic, and histologic features of orthokeratinized odontogenic cyst (OOC); determine the characteristics of multiple OOCs; and present rare but significant manifestations of OOC. A clinical, radiologic, and histopathologic study of 65 primary and 2 recurrent OOC cases was performed retrospectively along with a comprehensive literature review. OOCs shared similar radiologic findings with odontogenic keratocyst, yet some showed features that have not been previously described: root resorption and radiopaque foci. Histologic review revealed a unique histiocytic lining and some findings suggestive of the multipotentiality of the odontogenic epithelium. The analysis of patients with multiple OOCs demonstrated that multiple OOCs occurred synchronously with a marked predilection for young male adults. Two unusual cases were also identified: an OOC combined with a BRAFV600E ameloblastoma and a recurrent OOC with malignant transformation. This largest series presents previously unreported radiographic and histopathologic features that can be seen in OOC. Multiple OOCs have clinical characteristics distinct from those of solitary cases. The first reported OOC associated with ameloblastoma suggests the involvement of oncogenic mutations in odontogenic tumorigenesis. Although OOC shows a low recurrence rate, the possibility of malignant transformation of recurrent OOCs should be emphasized.