Similar Radiological Appearance Research Articles

What effective technique to differentiate radiation brain necrosis from a tumor progression in patients treated with radiation: A monocentric retrospective study combining the MRI TRAMs technique and the (18F)-dopa PET/CT

PurposeBrain necrosis after radiotherapy is a challenging diagnosis, since it has similar radiological appearance on standard MRI to tumor progression. Consequences on treatment decisions can be important. We compare recent imaging techniques in order to adopt a reliable diagnostic protocol in doubtful situations. Patients and methodThis is a retrospective study comparing the performance of three imaging techniques after radiotherapy of brain metastasis: Perfusion-MRI, TRAMs technique and F-dopa PET-CT. The evolution of the treated metastasis volume was also analyzed by contouring all patients MRIs. All included patients were suspected of relapse and had the three exams once the volume of treated metastasis increased. ResultsThe majority of our patients were treated by stereotactic radiotherapy. Suspicion of relapse was on average around 17months after treatment. Four cases of radionecrosis were diagnosed and six cases of real tumor progression. Neurological symptoms were less present in radionecrosis cases. All of our radionecrosis cases had relative cerebral blood volume below 1. F-dopa PET-CT succeeded to set the good diagnosis in eight cases, although we found one false positive and one false negative exam. The TRAMs technique failed in one case of false negative exam. ConclusionsPerfusion-MRI showed high performance in the diagnosis of radionecrosis, especially when calculating relative cerebral blood volume rate. The TRAMs technique showed interesting results and deserves application in daily routine combined with the perfusion-MRI. F-dopa CT might induce false results because of different metabolic uptake according to tumor type, medication and brain blood barrier leak.

Supratentorial Cystic Meningioma Resembling Pilocytic Astrocytoma: A Case Series and Literature Review

Introduction: Cystic meningioma is a rare subtype of meningioma. Various brain tumors may mimic cystic meningioma in imaging appearance. Herein, we reported a series of cases with cystic meningiomas primarily misdiagnosed as pilocytic astrocytoma due to a similar radiological appearance. Methods: This case-series study included 20 patients with cystic meningiomas admitted to the Ghaem Hospital, Mashhad, Iran, between 2012 and 2019. The findings of magnetic resonance imaging (MRI), computed tomography, and neurological examination were recorded preoperatively. All the patients underwent surgery, and biopsies were obtained, confirming the histopathological diagnosis of the tumor. Results: The patients’ mean age was 40.7±12.5 years, including 11 men and nine women. Most of the patients presented with headaches (50.0%), and hemiparesis (60.0%) was the most found in the neurological examination. All neuroimaging studies revealed solid-cystic supratentorial tumors, in which cysts were intratumoral, larger than solid components, and eccentric relative to them. Most of the cysts were located in the frontal lobe. The T2 weighted MR images’ signal intensity showed hypointense lesions in 25.0% of the cases; however, 45.0% of the patients were hyperintense and 30.0% of them were isointense to grey matter. After contrast injection, the tumor’s solid and periphery experienced a homogeneous enhancement. The most common histopathological finding was meningothelial cells (30.0%) followed by fibroblastic cells (25.0%). Conclusion: Cases with an initially diagnosed pilocytic astrocytoma in the imaging can turn out to show cystic meningioma after pathological assessments, which deserves clinicians’ notice.

Ultrasound Elastography in the Differentiation of Simple Cyst and Type I Hydatid Cyst of the Liver.

Hydatid cyst (HC) is a parasitic disease that is endemic particularly to the sheep-breeding regions of the world, our country included. Given their propensity to materialize most commonly in the liver, our study evaluates the value of ultrasound elastography in the differential diagnosis of simple cyst and type I HCs of the liver.The study involved a total of 73 cysts (22 simple cysts, 51 type I HCs) that were removed using the puncture aspiration injection reaspiration technique between 2016 and 2018. All measurements were made using a Siemens ACUSON S2000 (Siemens Healthcare, Erlangen, Germany) device with a 4-MHZ 4C1 convex probe, an acoustic radiation force impulse elastography procedure, and a Virtual Touch IQ option. The difference between the mean shearwave elastography (SWE) values of both groups was analyzed with an independent t test.Of the 70 patients involved in the study, 29 were female and 41 were male, with a mean ± SD age of 38.85 ± 17.62 years (range, 5-82 years). Upon the examination of the 22 simple cysts and the 51 HCs, the mean ± SD SWE values were found to be 2.6 ± 0.96 (0.96-4.25) and 2.8 ± 1.69 (0.66-4.84), respectively. No statistically significant difference was identified between the SWE values of type I HCs and simple cysts (P > 0.005).Although HCs and simple cysts had similar radiological appearances, and a relative difference was noted in the differentiation of the elastographic measurements, this difference was not statistically significant. Accordingly, more comprehensive and various studies are needed.

Molecular differential analysis of uterine leiomyomas and leiomyosarcomas through weighted gene network and pathway tracing approaches

ABSTRACT Uterine smooth muscular neoplastic growths like benign leiomyomas (UL) and metastatic leiomyosarcomas (ULMS) share similar clinical symptoms, radiological and histological appearances making their clinical distinction a difficult task. Therefore, the objective of this study is to identify key genes and pathways involved in transformation of UL to ULMS through molecular differential analysis. Global gene expression profiles of 25 ULMS, 25 UL, and 29 myometrium (Myo) tissues generated on Affymetrix U133A 2.0 human genome microarrays were analyzed by deploying robust statistical, molecular interaction network, and pathway enrichment methods. The comparison of expression signals across Myo vs UL, Myo vs ULMS, and UL vs ULMS groups identified 249, 1037, and 716 significantly expressed genes, respectively (p ≤ 0.05). The analysis of 249 DEGs from Myo vs UL confirms multistage dysregulation of various key pathways in extracellular matrix, collagen, cell contact inhibition, and cytokine receptors transform normal myometrial cells to benign leiomyomas (p value ≤ 0.01). The 716 DEGs between UL vs ULMS were found to affect cell cycle, cell division related Rho GTPases and PI3K signaling pathways triggering uncontrolled growth and metastasis of tumor cells (p value ≤ 0.01). Integration of gene networking data, with additional parameters like estimation of mutation burden of tumors and cancer driver gene identification, has led to the finding of 4 hubs (JUN, VCAN, TOP2A, and COL1A1) and 8 bottleneck genes (PIK3R1, MYH11, KDR, ESR1, WT1, CCND1, EZH2, and CDKN2A), which showed a clear distinction in their distribution pattern among leiomyomas and leiomyosarcomas. This study provides vital clues for molecular distinction of UL and ULMS which could further assist in identification of specific diagnostic markers and therapeutic targets. Abbreviations UL: Uterine Leiomyomas; ULMS: Uterine Leiomyosarcoma; Myo: Myometrium; DEGs: Differential Expressed Genes; RMA: Robust Multiarray Average; DC: Degree of Centrality; BC: Betweenness of Centrality; CGC: Cancer Gene Census; FDR: False Discovery Rate; TCGA: Cancer Genome Atlas; BP: Biological Process; CC: Cellular Components; MF: Molecular Function; PPI: Protein–Protein Interaction

Efficiency of diffusion-weighted MRI for differentiating radiologically similar simple and type I hydatid cysts of the liver.

Determining the nature of purely cystic hepatic lesions is essential because different kinds have different follow-ups, treatment options, and complications. To explore the potential of apparent diffusion coefficient (ADC) values of diffusion-weighted imaging (DWI) for the differentiation of type I hydatid cysts (HC) and simple liver cysts (SLC), which have similar radiological appearances. This single-center prospective study was conducted during 2016-2019. Round, homogenous, anechoic liver cysts >1 cm were classified according to at least two years of imaging follow-up, radiological features, serology, as well as puncture aspiration injection reaspiration procedure and pathology results. ADC values of 95 cysts (50 type I HCs and 45 SLCs) were calculated on DWI. The differences in ADC values were analyzed by independent t-test. Of 51 patients, 28 were female, 23 were male (mean age 32.07 ± 22.95 years; age range 5-82 years). Mean diameter of 45 SLCs was 2.59 ± 1.23 cm (range 1.2-7.6 cm) and ADCmean value was 3.03 ± 0.47 (range 2.64-5.85) while mean diameter of 50 type I HCs was 7.49 ± 2.95 cm (range 2.8-14 cm) and ADCmean value was 2.99 ± 0.29 (range 2.36-3.83). There was no statistically significant difference in ADC values between type I HCs and SLCs. Some studies report that ADC values of type I HCs are statistically significantly lower than those of SLCs. Others suggest no significant difference. In our study with a higher number of cases, using ADC parameters similar to those in previous studies, we did not find any statistically significant difference.

COV19-CNNet and COV19-ResNet: Diagnostic Inference Engines for Early Detection of COVID-19.

Chest CT is used in the COVID-19 diagnosis process as a significant complement to the reverse transcription polymerase chain reaction (RT–PCR) technique. However, it has several drawbacks, including long disinfection and ventilation times, excessive radiation effects, and high costs. While X-ray radiography is more useful for detecting COVID-19, it is insensitive to the early stages of the disease. We have developed inference engines that will turn X-ray machines into powerful diagnostic tools by using deep learning technology to detect COVID-19. We named these engines COV19-CNNet and COV19-ResNet. The former is based on convolutional neural network architecture; the latter is on residual neural network (ResNet) architecture. This research is a retrospective study. The database consists of 210 COVID-19, 350 viral pneumonia, and 350 normal (healthy) chest X-ray (CXR) images that were created using two different data sources. This study was focused on the problem of multi-class classification (COVID-19, viral pneumonia, and normal), which is a rather difficult task for the diagnosis of COVID-19. The classification accuracy levels for COV19-ResNet and COV19-CNNet were 97.61% and 94.28%, respectively. The inference engines were developed from scratch using new and special deep neural networks without pre-trained models, unlike other studies in the field. These powerful diagnostic engines allow for the early detection of COVID-19 as well as distinguish it from viral pneumonia with similar radiological appearances. Thus, they can help in fast recovery at the early stages, prevent the COVID-19 outbreak from spreading, and contribute to reducing pressure on health-care systems worldwide.

Cerebral aspergillose

The diagnosis of intracerebral fungal abscesses may be difficult due to the paucity of laboratory tests and similar radiological appearance to other lesions. We present an immunocompromised woman in her forties who was admitted with a diagnosis of bacterial meningitis. MRI examination showed findings suggestive of fungal abscesses, and a subsequent lumbar puncture showed PCR positive for non-fumigatus Aspergillus. The patient received antifungal treatment and had satisfactory clinical, biochemical and radiological response. Consecutive MRI examinations over the following weeks showed gradual decrease of abscesses, with almost complete resolution within 12 weeks. Adequate management of brain abscesses requires correct identification of the causative agent, so that proper treatment can be initiated as soon as possible. MRI plays an important role in distinguishing between pyogenic and fungal brain abscesses. Headaches or focal neurological deficits in immunocompromised patients should cause CNS fungal infection to be considered.

The Utility of Whole Body Imaging in the Evaluation of Solitary Brain Tumors

Solitary brain tumors can propose a diagnostic dilemma owing to the difficulty in differentiating between primary brain tumors and metastatic disease. The similar radiologic appearance on routine magnetic resonance imaging will necessitate the need for additional noninvasive testing. We sought to determine the clinical utility of preoperative whole body screening with computed tomography (CT) to detect metastatic disease in patients with solitary brain tumors. A prospectively maintained surgical database for a large quaternary care academic institution was retrospectively reviewed for all patients undergoing craniotomy for a new diagnosis of enhancing solitary brain lesion from January 2011 to January 2016. Patients were excluded if the imaging findings had demonstrated multiple brain tumors, they had a known diagnosis of malignancy, or they had undergone previous craniotomy. The demographic and radiographic information and clinical and histopathologic data were collected and tallied. A total of 218 patients with solitary brain tumors met the inclusion criteria and were included in the present study. Histopathologic analysis confirmed primary central nervous system tumors in 152 patients (74.4%) and metastatic disease in 66 (25.6%). Preoperative screening with whole body CT had a sensitivity of 0.92 and specificity of 0.95 for detecting systemic metastases in the patients. Preoperative whole body CT correctly identified systemic malignancy in 88% of the patients ultimately diagnosed with metastasis (positive predictive value, 88%). Of those with negative whole body imaging findings, 97% had a diagnosis of a primary central nervous system neoplasm (negative predictive value, 97%). Preoperative whole body CT had a positive predictive value of 88% and negative predictive value of 97% in the present study and was both sensitive (92%) and specific (95%) for the detection of extracranial tumors. The identification of extracranial tumors on whole body CT screening might alter management.

Anterolateral Approach for Central Thoracic Disc Prolapse-Surgical Strategies Used to Tackle Differing Operative Findings: 3-Dimensional Operative Video.

Thoracic disc prolapses causing cord compression can be challenging. For compressive central disc protrusions, a posterior approach is not suitable due to an unacceptable level of cord manipulation. An anterolateral transthoracic approach provides direct access to the disc prolapse allowing for decompression without disturbing the spinal cord. In this video, we describe 2 cases of thoracic myelopathy from a compressive central thoracic disc prolapse. In both cases, informed consent was obtained. Despite similar radiological appearances of heavy calcification, intraoperatively significant differences can be encountered. We demonstrate different surgical strategies depending on the consistency of the disc and the adherence to the thecal sac. With adequate exposure and detachment from adjacent vertebral bodies, soft discs can be, in most instances, separated from the theca with minimal cord manipulation. On the other hand, largely calcified discs often present a significantly greater challenge and require thinning the disc capsule before removal. In cases with significant adherence to dura, in order to prevent cord injury or cerebrospinal fluid leak a thinned shell can be left, providing total detachment from adjacent vertebrae can be achieved. Postoperatively, the first patient, with a significantly calcified disc, developed a transient left leg weakness which recovered by 3-month follow-up. This video outlines the anatomical considerations and operative steps for a transthoracic approach to a central disc prolapse, whilst demonstrating that computed tomography appearances are not always indicative of potential operative difficulties.

Radiological and Pathological Characteristics of Mandibular Cystic Lesion – A Review

Many lesions that occur in the jaw have a similar radiological appearance and it is often difficult to differentiate among them. Cysts that are present in the mandible are commonly noted on head and neck imaging and present a diagnostic dilemma. These lesions are often identified as incidental lesions by the radiologist on imaging performed for different reasons. Collaborative interaction between the dentists, oral surgeon, radiologist and oral pathologist is essential for the appropriate evaluation, imaging, and treatment of cystic appearing lesions of the mandible.

Immunoglobulin G4–related disease mimicking an epidural spinal cord tumor: case report

The authors report a case of immunoglobulin G4-related disease (IgG4-RD) presenting as a paraspinal, epidural mass. This disease encompasses a host of autoimmune conditions that were previously thought to be separate entities. It is characterized by fibrosis, mediated by the aberrant proliferation and tissue invasion of IgG4-positive plasma cells, which can occur in any organ. As with other autoimmune conditions, it tends to be responsive to steroids and other immunosuppressants. It can rarely present as a tumefactive lesion of the central nervous system, creating the potential for misdiagnosis (given its similar radiological appearance to malignancy) and mistreatment. In 2015, a panel of experts convened to set forth guidelines for the diagnosis and treatment of IgG4-RD. In the case presented here, the patient initially presented with pain and weakness in the left upper extremity. Initial neuroimages revealed a contrast-enhancing mass extending from C-4 to T-1, invading the epidural spinal canal, encasing the exiting nerve roots, infiltrating the paraspinal musculature, and surrounding the left vertebral artery. A PET scan confirmed the mass was hypermetabolic, but results of fine-needle aspiration and CT-guided biopsy were inconclusive. Open biopsy yielded fibrotic tissue that met the pathological criteria for IgG4-RD: lymphoplasmacytic infiltrate, fibrosis in a storiform pattern, and obliterative phlebitis. The patient was treated with 2 doses of 4 mg of dexamethasone (Decadron) and then 50 mg of prednisone per day. Within 2 weeks, the mass was radiologically shown to have drastically decreased in size. The prednisone dose was decreased to 40 mg per day, and 100 mg of azathioprine per day was added. The patient continued to improve and the mass continued to decrease over the next 6 months. Currently, she has been weaned from all steroids and will be maintained on a daily dose of 100 mg of azathioprine.

Sunflower seed mimicking complicated hydatid cyst

We present a case of a foreign body in lung parenchyma, found incidentally during surgery in an adult woman. The clinical and radiological findings were consistent with a pulmonary hydatid cyst. Owing to the similar clinical and radiological appearances, a thoracotomy was required for the correct diagnosis of a sunflower seed mimicking hydatid disease.

S43 Real World Experience Of The Use Of Pet-ct For Distinguishing Between Benign Pleural Disease And Malignant Mesothelioma

Patients presenting with pleural disease on a background of asbestos exposure pose a diagnostic dilemma. Malignant mesothelioma and benign pleural disease have similar radiological appearances but markedly different prognoses. Definitive histological diagnosis is gold standard, however, there are small case series where PET-CT has been compared to pleural biopsy. These have suggested cut-off standardised uptake values (SUV) of 2.0–3.0, with reported sensitivity of 94.1–100% and specificity of 94–100% for excluding pleural malignancy. It has been suggested that where the CT appearances are more in keeping with a benign aetiology, pleural avidity on PET-CT may be able to adequately distinguish between benign and malignant disease, identifying a low-risk population that can be observed in preference to proceeding to thoracoscopy. We are a cardiothoracic centre which utilises PET-CT in this way. We aimed to review our single-centre experience to see if our outcomes were consistent with the reported data. All PET-CT reports carried out since 2007 with the mention of pleura/pleural within the request or report were reviewed. Radiological reports and patient records were examined, scans requested primarily for assessment of the pleura were included. Indication, radiological diagnosis, final diagnosis, presence of histological confirmation and duration of follow-up were determined. All patients with at least 6 months follow-up were analysed. 185 PET CT scan reports were reviewed, of which 28 were carried out primarily for assessment of pleural disease. 9 were found to have high SUVs suggestive of malignancy. 7 of which were demonstrated to be mesothelioma, 1 pleural tumour, 1 recurrence of non-small cell lung cancer. The remaining 19 were reported to have low SUVs, consistent with benign pleural disease. For those with PET findings consistent with benign pleural disease, follow up data was available for a median of 12 months (Min 6- Max 66). One patient underwent pleural biopsy, which was consistent with benign disease. None of those designated as benign pleural disease based on PET-CT appearances were subsequently found to have pleural malignancy. Our findings are consistent with previously published data and support the utility of PET-CT scanning in differentiating benign from malignant pleural disease in a clinical setting.

The radiological and histopathological differential diagnosis of chordoid neoplasms in skull base

Background Chordoid neoplasms refer to tumors appearing to have histological features of embryonic notochord, which is characterized by cords and lobules of neoplastic cells arranged within myxoid matrix. Because of radiological and histological similarities with myxoid matrix and overlapping immunohistochemical profile, chordoma, chordoid meningioma, chordoid glioma, and rare extraskeletal myxoid chondrosarcoma enter in the radiological and histological differential diagnosis at the site of skull base. However, there is always a great challenge for histopathologists to make an accurate diagnosis when encountering a chordoid neoplasm within or near the central nervous system. The aim of this study is to investigate and summarize the radiological, histological features and immunohistochemical profiles of chordoid neoplasms in skull base, and to find a judicious panel of immunostains to unquestionably help in diagnostically challenging cases. Methods A total of 23 cases of chordoid neoplasms in skull base, including 10 chordomas, 5 chordoid meningiomas, 3 chordoid gliomas and 5 extraskeletal myxoid chondrosarcomas, were collected from the First Affiliated Hospital, Sun Yat-sen University and Guangdong Tongjiang Hospital. MRI examination was performed on the patients before surgical treatment. Microscopical examination and immunohistochemical staining study using vimentin (Vim), pan-cytokeratin (PCK), epithelial membrane antigen (EMA), S-100 protein (S-100), glial fibrillary acidic protein (GFAP), D2-40, Galectin-3, CD3, CD20, Ki-67 were performed on the samples of cases. The clinicopathological data of the patients was also analyzed retrospectively. Results Most of chordomas were localized in the clivus with heterogeneous hyperintensity on T2WI scanning. The breakage of clivus was observed in most cases. Histologically, the tumor cells of chordoma exhibited bland nuclear features and some contained abundant vacuolated cytoplasm (the so-called physaliferous cells) within myxoid matrix. Areas of cartilage presented in individual cases. The tumor cells of chordoma were diffusely immuno-positive for PCK and EMA. Chordoid meningioma is characterized by a homogeneous contrast-enhancing mass with dural tail sign. The epithelioid cells were arranged in cords and clusters within a myxoid matrix, which was highly reminiscent of chordoma. The ratio of myxoid component and conventional meningioma was different in tumors. EMA was detectable in all chordoid meningiomas, and 4/5 cases were positive for D2-40. That was a finding which was helpful in distinguishing chordoid meningioma from chordoma. Chordoid gliomas were localized in the third ventricle with homogeneous enhancement on MRI examination. The tumors were composed of clusters and cords of epithelioid tumor cells within a variably mucinous stroma containing lymphoplasmacytic infiltratation. The most distinctive immunohistochemical feature of chordoid gliomas is their strong diffuse reactivity for GFAP. EMA and PCK positive expression can also be seen focally in individual cases. Although extraskeletal myxoid chondrosarcomas share the similar radiological and histological appearance with chordoma, all chondrosarcomas in the present study are completely negative for epithelial markers except for immuno-positivity of S-100 focally. In addition, Galectin-3 can be detected in most of chordoid neoplasms in skull base. Conclusion The specific localization and MRI features of tumors are useful diagnostic clues for the differential diagnosis of chordoid neoplasms in skull base. However, combining with histological features, a panel of selected immunostains, including PCK, EMA, GFAP, S-100 and D2-40, is helpful in making an accurate diagnosis for those diagnostically challenging cases which usually appear to have atypical radiological features or in an unusual site. Ki-67 index and Galectin⁃3 are not recommended to use as diagnostic markers for chordoid neoplasms of skull base because of their less neoplastic specificity.

Differential diagnosis of intracranial meningiomas based on magnetic resonance spectroscopy

Background and purposeTo determine in vivo magnetic resonance spectroscopy (MRS) characteristics of intracranial meningiomas and to assess MRS reliability in meningioma grading and discrimination from tumours of similar radiological appearance, such as lymphomas, schwannomas and haemangiopericytomas. Material and methodsAnalysis of spectra of 14 patients with meningiomas, 6 with schwannomas, 2 with lymphomas, 2 with haemangiopericytomas and 17 control spectra taken from healthy hemispheres. ResultsAll the patients with meningiomas had a high Cho signal (long TE). There were very low signals of Naa and Cr in the spectra of 10 patients. A reversed Ala doublet was seen only in 2 cases. Four patients had a negative Lac signal, whereas 3 had high Lac-Lip spectra. Twelve spectra showed high Cho signals (short TE). In one case the Cho signal was extremely low. All spectra displayed a very low Cr signal, but high Glx and Lac-Lip signals. Ala presence was found only in 3 patients. The mean Cho/Cr ratio (PRESS) was 5.97 (1.12 in normal brain, p < 0.05). Lac-Lip was present in all the meningiomas (STEAM). The Ala signal was seen only in 2 spectra with long TE and in 3 sequences of the short TE sequences. There were both β/γ-Glx and α-Glx/glutathione signals in all 14 meningiomas. ConclusionsMRS is unable to discriminate low and high grade meningiomas. The method seems to be helpful in discriminating lymphomas (absent Glx signal), schwannomas (mI signal in the short TE sequences) and haemangiopericytomas (presence of mI band) from meningiomas.

Giant cell bone lesions in the craniofacial region: a diagnostic and therapeutic challenge

Giant cell tumors of bone (GCTs) are common in the long bones, but rare in the craniofacial region, with only 1% of cases occurring in the latter. Clinical, radiological, and anatomical diagnosis of this locally aggressive disease, which occurs in response to trauma or neoplastic transformation, poses a major challenge in clinical practice. The present study describes a series of 4 cases and highlights the main features of the differential diagnosis and treatment of these lesions: GCT, giant cell reparative granuloma (GCRG), and the brown tumor of hyperparathyroidism. GCT presents as a benign neoplasm, most typically affecting the knees, and rarely in the temporal and sphenoid bones. It is radiologically indistinguishable from GCRG due to its lytic, poorly defined appearance. The distinction can only be made microscopically, as the presence of multinucleated giant cells scattered throughout the stroma and the absence of a history of trauma favor a diagnosis of GCT. The brown tumor of hyperparathyroidism occurs with rapid, localized osteoclast activity secondary to the effects of increased parathyroid hormone (PTH) levels; parathyroid examination is indispensable. The diagnosis and treatment of these lesions poses a major challenge due to their similar clinical presentation and radiological appearance. Accurate diagnosis is essential for definition of appropriate management, as complete resection is the goal in GCT and GCRG to avoid recurrence, whereas the brown tumor often yields to treatment of the underlying hyperparathyroidism.

Primary central nervous system lymphoma presenting as a pure third ventricular lesion: a case report

IntroductionPrimary central nervous system lymphomas are infrequently occurring lymphomas that account for only 0.3-1.5% of all intra-cranial neoplasms in patients without acquired immune deficiency syndrome. However, a pure third ventricle lymphoma is extremely rare. Here, we discuss the similar radiological appearances of lesions localized in the third ventricle and the importance of accurately diagnosing primary central nervous system lymphomas for favorable treatment outcomes.Case presentationA 38-year-old Caucasian man from Turkey presented with a severe headache lasting for three months that failed to respond to any medication. Both severity and duration of the symptoms increased gradually, resulting in vomiting, nausea and gait disturbance that accompanied the headache for three weeks. Neuro-imaging studies showed a lesion located solely in the third ventricle, resulting in partial obstruction of the foramen of Monro. The pre-operative diagnosis was a colloid cyst. Following the surgical procedure, the results of pathological and immunochemical assays revealed that the pre-operative diagnosis was incorrect and that the lesion was a primary central system lymphoma.ConclusionPure third ventricle lymphomas are extremely rare and are exceptionally localized. It is important to be aware of, and to differentiate between, other possible third ventricular lesions that may mimic the same radiological appearance. Accurate diagnosis is necessary for selecting appropriate treatment modalities.

Dorsal prevertebral lesions in Wegener granulomatosis: Report on four cases

Retroperitoneal fibrosis has been reported in several patients with Wegener granulomatosis (WG), but only three isolated cases of dorsal prevertebral lesions, closely resembling fibrosing mediastinitis, have been published so far. We describe four new WG patients (two men, two women), 49–59 years old at diagnosis, with dorsal prevertebral lesions, mainly right-sided, and with adjacent pleural thickening in two. These lesions were detected on computed-tomography scans at diagnosis in two patients, and occurred later in the two others. Only one of them had mild back pain. Two patients’ lesions were biopsied, revealing granulomatous inflammation. In one patient, the lesion regressed under WG treatment. Lesion size did not change in the remainings. Intralesional calcifications appeared in two. None of the patients had local bone erosion, vascular or neurological complications. These prevertebral lesions might represent a dorsal form of retroperitoneal fibrosis in WG, but usually with a more benign presentation and course. WG should be included in the differential diagnosis of fibrosing mediastinitis (with tuberculosis, neoplastic diseases, sarcoidosis, histiocytosis and inflammatory pseudotumor), which may have a similar radiological appearance.

Treatment of posterior ankle pain by excision of a bipartite talar fragment

We describe five adolescent patients aged between 13 and 16 years with bipartite ossification of the posteromedial aspect of the talus. All presented without a history of trauma. All the ankles had a similar radiological appearance. Clinically, some restriction of movement was noted in three ankles and two subtalar joints, In addition, pain was noted over the posteromedial aspect of the ankle in three patients. In each patient the bipartite fragment was excised through a posteromedial approach to the ankle. Complete resolution was achieved at six months in three patients, with the remaining two describing exercise-induced symptoms. In one of these this precluded participation in sport. Despite numerous anatomical variations within the tarsus, a case series of a bipartite talus has not previously been reported. This anatomical variation should be recognised to avoid misinterpretation as post-traumatic or other pathological processes. In the presence of recalcitrant symptoms excision is an option, but this is not universally successful in abolishing symptoms.

Simultaneous choroid plexus carcinoma and pilocytic astrocytoma in a pediatric patient

Simultaneous primary brain tumors in pediatric patients without prior chemotherapy or radiotherapy, phacomatosis, or known familial history are a rare occurrence. The authors report the case of a 4-year-old boy with simultaneous choroid plexus carcinoma and pilocytic astrocytoma with features of oligodendroglioma. Magnetic resonance imaging studies revealed diffuse heterogeneously enhancing left intraventricular and posterior fossa tumors initially believed most consistent with multicentric choroid plexus carcinomas. A multiple staged resection was carried out for each tumor and gross-total resection was achieved. Upon gross inspection intraoperatively as well as postoperative histological analysis, 2 distinct simultaneous tumors were identified: choroid plexus carcinoma and pilocytic astrocytoma. To the authors' knowledge this is the first case report published identifying 2 distinct tumor types with similar radiological appearances in a pediatric patient with no prior history of radiotherapy, chemotherapy, or phacomatosis.