Challenges in radiological evaluation of brain metastases, beyond progression.

MRI is the cornerstone in the evaluation of brain metastases. The clinical challenges lie in discriminating metastases from mimickers such as infections or primary tumors and in evaluating the response to treatment. The latter sometimes leads to growth, which must be framed as pseudo-progression or radionecrosis, both inflammatory phenomena attributable to treatment, or be considered as recurrence. To meet these needs, imaging techniques are the subject of constant research. However, an exponential growth after radiotherapy must be interpreted with caution, even in the presence of results suspicious of tumor progression by advanced techniques, because it may be due to inflammatory changes. The aim of this paper is to familiarize the reader with inflammatory phenomena of brain metastases treated with radiotherapy and to describe two related radiological signs: "the inflammatory cloud" and "incomplete ring enhancement", in order to adopt a conservative management with close follow-up.

Los retos en la evaluación radiológica de las metástasis cerebrales, más allá de la progresión / Challenges in radiological evaluation of brain metastases, beyond progression

La resonancia magnética es la piedra angular en la evaluación de las metástasis cerebrales. Los retos clínicos residen en discriminar las metástasis de imitadores como infecciones o tumores primarios y en evaluar la respuesta al tratamiento. Este, en ocasiones, condiciona un crecimiento, que debe encuadrarse como una pseudoprogresión o una radionecrosis, ambos fenómenos inflamatorios atribuibles al mismo, o bien considerarse como una recurrencia. Para responder a estas necesidades, las técnicas de imagen son objeto de constantes investigaciones. No obstante, un crecimiento exponencial tras la radioterapia debe interpretarse con cautela, incluso ante resultados sospechosos de progresión por técnicas avanzadas, ya que puede tratarse de una radionecrosis. El objetivo de este trabajo es familiarizar al lector con los fenómenos inflamatorios de las metástasis cerebrales tratadas con radioterapia y describir dos signos radiológicos relacionados: la «nube inflamatoria» y el «realce en anillo incompleto», con el fin de adoptar un manejo conservador en estos casos.(AU)

MRI is the cornerstone in the evaluation of brain metastases. The clinical challenges lie in discriminating metastases from mimickers such as infections or primary tumors and in evaluating the response to treatment. The latter sometimes leads to growth, which must be framed as pseudo-progression or radionecrosis, both inflammatory phenomena attributable to treatment, or be considered as recurrence. To meet these needs, imaging techniques are the subject of constant research. However, an exponential growth after radiotherapy must be interpreted with caution, even in the presence of results suspicious of tumor progression by advanced techniques, because it may be due to inflammatory changes. The aim of this paper is to familiarize the reader with inflammatory phenomena of brain metastases treated with radiotherapy and to describe two related radiological signs: «the inflammatory cloud» and «incomplete ring enhancement», in order to adopt a conservative management with close follow-up.(AU)

Could breast multiparametric MRI discriminate between pure ductal carcinoma in situ and microinvasive carcinoma?

BACKGROUND: Ductal carcinoma in situ (DCIS) is often reclassified as invasive cancer in the final pathology report of the surgical specimen. It is of significant clinical relevance to acknowledge the possibility of underestimating invasive disease when utilizing preoperative biopsies for a DCIS diagnosis. In cases where such histologic upgrades occur, it is imperative to consider them in the preoperative planning process, including the potential inclusion of sentinel lymph node biopsy due to the risk of axillary lymph node metastasis. PURPOSE: To assess the capability of breast multiparametric magnetic resonance imaging (MP-MRI) in differentiating between pure DCIS and microinvasive carcinoma (MIC). MATERIAL AND METHODS: Between January 2018 and November 2022, this retrospective study enrolled patients with biopsy-proven DCIS who had undergone preoperative breast MP-MRI. We assessed various MP-MRI features, including size, morphology, margins, internal enhancement pattern, extent of disease, presence of peritumoral edema, time-intensity curve value, diffusion restriction, and ADC value. Subsequently, a logistic regression analysis was conducted to explore the association of these features with the pathological outcome. RESULTS: Of 129 patients with biopsy-proven DCIS, 36 had foci of micro-infiltration on surgical specimens and eight were diagnosed with invasive ductal carcinoma (IDC). The presence of micro-infiltration foci was significantly associated with several MP-MRI features, including tumor size (P <0.001), clustered ring enhancement (P <0.001), segmental distribution (P <0.001), diffusion restriction (P = 0.005), and ADC values <1.3 × 10-3 mm2/s (P = 0.004). CONCLUSION: Breast MP-MRI has the potential to predict the presence of micro-infiltration foci in biopsy-proven DCIS and may serve as a valuable tool for guiding therapeutic planning.

Cerebral mucormycosis masquerading as brain metastasis from lung cancer: A case report.

We report a rare case of concurrent pulmonary and cerebral mucormycosis initially misdiagnosed as a metastatic tumor. A 66-year-old man with a complaint of progressive right-sided limb weakness for 3 days. Head MRI showed a left parietal occupying lesion with severe edema, and a chest CT scan showed a parenchymal mass with speculation and pleural invasion in his left lung. The patient was initially diagnosed with brain metastases from lung cancer and underwent a craniotomy. Many fungal hyphae were found in the left parietal lesion, and the final pathological diagnosis of intracranial mucormycosis. After craniotomy and an entire course of treatment with liposomal amphotericin B, the patient was completely cured of both intracranial and pulmonary occupying lesions. We hope that this case experience will help expand neurosurgeons' differential diagnosis and treatment of such diseases.

Cerebral syphilitic gumma mimicking a brain tumor that enlarged temporarily after commencing antibiotic treatment.

In this case report, we describe a 60-year-old man who presented with headaches for 1 year and mild confusion for 3 weeks and was initially diagnosed as having a cerebral tumor on the basis of finding a round lesion in the right lenticular nucleus with ring enhancement on gadolinium-enhanced T1-weighted brain magnetic resonance imaging. However, the discovery of positive serology for Treponema pallidum infection on routine tests on admission prompted analysis of cerebrospinal fluid, which was also positive on Treponema pallidum hemagglutination (TPHA), rapid plasma reagin (RPR), and treponemal antibody absorption (FTA-ABS) tests. Thus, he was diagnosed as having an intracranial syphilitic gumma. After commencing treatment with penicillin G, the lesion temporarily increased in size, but subsequently resolved completely with continuing antibiotic treatment. In the present era of increasing prevalence of syphilitic infection and because they are eminently treatable, syphilitic gummas should be included in the differential diagnosis of apparent brain tumors. Additionally, temporary enlargement of a probable gumma after instituting antibiotic treatment should not prompt cessation or change of the antibiotics.

Polymicrobial periprosthetic joint infection and osteomyelitis of the tibia with circumferential abscess and skin ulcer 11 years after total knee arthroplasty.

We report the case of a 71-year-old woman with a skin ulcer derived from an abscess around the tibia. The abscess resulted in periprosthetic joint infection and osteomyelitis 11 years after total knee arthroplasty. The first symptom was a skin ulcer of the lower leg. Magnetic resonance imaging revealed a circumferential mass around the proximal tibia. A skin biopsy taken around the ulcer showed thrombosis and degenerated collagen. Contrast-enhanced computed tomography showed a circumferential mass around the proximal tibia with ring enhancement. Biopsies of the skin ulcer and circumferential mass showed an abscess caused by Enterococcus faecium and methicillin-resistant Staphylococcus epidermis. We conducted debridement of the abscess, a gastrocnemius flap and split-thickness skin grafting and a 2-stage revision of the total knee component with a hinged prosthesis. Two years later, the infection did not reoccur and the patient can walk without a cane. This case is unique as abscess around proximal tibia caused necrotic skin ulcer and appearance of abscess was fibrous and different from typical bacterial abscesses containing pus or fluid. Contrast-enhanced computed tomography was effective for differentiation of the pathological condition.

Prediction of BRAF mutation status in glioblastoma multiforme by preoperative ring enhancement appearances on MRI.

Background: Ring enhancement on magnetic resonance imaging (MRI) is an important characteristic of GBM. Though patients suffering from glioblastoma multiforme (GBM) with BRAF mutation (MUT BRAF) in V600E benefit from BRAF-targeted inhibitors, the relationship between ring enhancement and MUT BRAF remains elusive. The purpose of this study was to investigate the relationship between BRAF mutation status and the appearance of ring enhancement so as to guide preoperative targeted therapy for MUT BRAF GBM. Methods: Patient's population, clinical data and characteristic ring enhancement appearances on MRI were compared between GBM with MUT BRAF and GBM with WT BRAF. A receiver operating characteristic (ROC) curve analysis was performed to evaluate the differential diagnostic significance. A nomogram was developed to predict the mutation status of BRAF. Moreover, all the variables were re-analyzed between epithelioid GBM (E-GBM) with or without MUT BRAF. Results: Compared to GBM with WT BRAF, GBM with MUT BRAF had specific ring enhancement appearances with multiple rings, multiple located lobes, regular shape of ring, uniform thickness of ring and smaller diameter of ring. Area under the curve (AUC) of all the variables' combination was 0.929. The nomogram was developed and validated. The re-analyzed results between E-GBM with or without MUT BRAF were similar to these above. AUC of the combination of quantity of ring, quantity of located lobe and shape of ring was 0.962. Conclusion: The characteristic ring enhancement appearances of GBM may play an important role in predicting BRAF mutation status preoperatively, especially in E-GBM. Further study with larger cases may provide more evidences to guide the pretreatment of targeted medicine for GBM patients with MUT BRAF in future.

A case of autoimmune glial fibrillary acidic protein astrocytopathy presenting with magnetic resonance imaging mimics of multiple sclerosis.

Autoimmune glial fibrillary acidic protein (GFAP) astrocytopathy is an inflammatory disorder of the central nervous system. On magnetic resonance imaging, the neuroradiological signature is a linear radial enhancement pattern of cerebral white matter (MRI). Dawson's fingers, on the other hand, and ovoid lesions with open-ring enhancement have long been recognized as distinct features of multiple sclerosis (MS). We herein report a case of autoimmune GFAP astrocytopathy presenting with these MRI findings specific to MS. Autoimmune GFAP astrocytopathy could mimic the MRI features of MS and should be included in the differential diagnosis of MS.

Tumor Vascular Microenvironment of Colorectal Hepatic Metastasis and Chemotherapy Response.

BACKGROUND: The tumor vascular microenvironment has an important role in tumor progression and metastasis. The objective of this study was to assess the significance of metastatic hepatic tumor vascular microenvironment in relation to the response to systemic fluorouracil-based chemotherapy [folinic acid/fluorouracil/oxaliplatin (FOLFOX) or folinic acid/fluorouracil/irinotecan (FOLFIRI)]. PATIENTS AND METHODS: A total of 48 consecutive patients with colorectal cancer (CRC) with hepatic metastasis were retrospectively reviewed, and factors such as metastatic tumor vascular microenvironment, chemotherapy response and hepatic resection, were analyzed. Tumor angiogenesis was microscopically evaluated by microvessel density (MVD) in sections stained immunochemically with antibody to CD34 in patients with hepatic resection. Angiogenesis in the tumor microenvironment in association with ring enhancement (RE) on computed tomography (CT) was also examined. RESULTS: Microscopic examination revealed that peripheral RE on CT of the metastatic tumor was associated with tumor angiogenesis by MVD. The overall response rate after six courses of first-line chemotherapy for liver metastasis with RE on CT was 64% (23/36), whereas the response rate for those without RE was 25% (3/12), which was significantly lower, although the survival of patients with RE-positive and RE-negative tumors did not differ significantly. CONCLUSION: Peripheral RE of metastatic hepatic tumor on CT was associated with angiogenesis in the tumor microenvironment and higher chemotherapy response.

[A case of brain tuberculoma resembling a malignant tumor].

A 35-year-old Sudanese man experienced bitter tastes on the right side of his tongue from January 2012. He was admitted to our hospital in March 2012 because of the appearance of distress, right facial palsy, nausea, and dizziness from late February 2012. A neurological examination revealed Bruns nystagmus, which increased on rightward gaze, as well as total hypoesthesia in the distribution of the maxillary branch of the right trigeminal nerve, moderate right peripheral type facial nerve palsy, and limb ataxia on the right side. Neither muscle weakness nor sensory disturbance was observed. Slight hyperreflexia was noted in the right extremities, and bilateral plantar responses were flexor. He showed wide-based ataxic gait and was unable to do tandem gait. Brain CT scans and magnetic resonance (MR) images revealed a mass lesion in the right pons to the right middle cerebellar peduncle with ring enhancement, suggestive of a "target" sign. Laboratory tests, including hematological and biochemical analyses, tumor markers, and antibodies, had normal values while the tuberculin reaction and QuantiFERON-TB Gold were strongly positive. Cerebrospinal fluid analysis revealed a slight increase in the protein level (76 mg/dl) with a normal cell count (2 per µl), and polymerase chain reaction-based tests and cultures were negative for Mycobacterium tuberculosis three times. Right subclavicular lymph node and right adrenal gland showed accumulation of fluorodeoxyglucose on positron emission tomography-CT, as did the mass lesion in the brainstem. These findings suggested a possibility of a metastatic malignant tumor or extrapleural tuberculoma. Because of the patient's religious belief, we were unable to perform a biopsy of the lymph node, and thus administered anti-tuberculous drugs. With treatment, his neurological symptoms such as facial palsy and ataxia improved steadily except for paradoxical worsening for the initial five days, and the gadolinium-enhanced lesion shrunk markedly. Follow-up MR images demonstrated that the lesions did not expand further for 9 months. From this course of treatment, we diagnosed the patient's tumor as brainstem tuberculoma. Brain tuberculoma sometimes resembles a malignant tumor, and it is therefore challenging to diagnose brainstem tuberculosis in cases without lung lesions. It is important to make a comprehensive diagnosis based on the patient's background, imaging, and course of treatment, and to treat brainstem tuberculoma promptly.

Meningioma with ring enhancement on MRI: a rare case report.

BACKGROUND: Meningiomas typically manifest on magnetic resonance imaging (MRI) as iso- to hypointense on T1-weighted imaging and iso- to hyperintense on T2-weighted imaging. After contrast administration, they usually homogeneously enhance and exhibit a visible dural tail. Meningiomas with atypical findings may be misdiagnosed. CASE PRESENTATION: We report a 50-year-old female patient with a pathologically diagnosed fibrous meningioma (World Health Organization grade I) that exhibited ring enhancement on MRI. CONCLUSIONS: Meningiomas may rarely present with ring enhancement on MRI. The natural history and mechanisms of cystic degeneration and enhancement in the various types of meningioma require further study.

Value of MRI in diagnosis of benign and malignant breast lesions with cluster ring enhancement / 国际肿瘤学杂志

Objective:To investigate the diagnostic value of MRI in benign and malignant breast lesions with cluster ring enhancement.Methods:The imaging signs of 68 patients with clustered ring enhancement who underwent MRI examination due to clinical palpation, ultrasound or X-ray examination for suspected malignant lesions in Tangdu Hospital of Air Force Military Medical University from October 2017 to July 2019 were retrospectively analyzed. The differences between benign and malignant lesions in the distribution pattern, T2 lipid suppression signal intensity, time-signal intensity curve (TIC), ductal dilatation, peripheral gland edema, pectoralis major edema were compared using χ2 test or Mann-Whitney U test, and the risk factors of MRI imaging signs of malignant breast lesions were analyzed using binomial logistic regression model. Results:There were 68 cluster ring enhancement lesions in 68 patients, all of which were single lesions, among which 18 cases (26.5%) were benign, and the common lesions were plasma cell mastitis (9 cases). Fifty cases (73.5%) were malignant, and the most common type was invasive breast cancer (40 cases). Imaging features of plasma cell mastitis showed cluster ring enhancement, regional distribution, slightly high signal on fat suppression T2 image, type Ⅲ TIC, with ductal dilatation, edema of peripheral glands and pectoralis major. Imaging features of invasive breast cancer showed cluster ring enhancement, regional distribution, iso-signal on fat suppression T2 image, type Ⅲ TIC, no ductal dilatation, and edema of peripheral gland and pectoralis major. There were statistically significant differences in the intensity of fat-suppression T2 signal ( Z=3.003, P=0.003) and duct dilatation ( χ2=7.174, P=0.007) between benign and malignant lesions. There were no significant differences in distribution ( χ2=5.510, P=0.313), TIC type ( χ2=3.538, P=0.133), peripheral gland edema ( χ2=0.164, P=0.686) and pectoralis major edema ( χ2<0.001, P>0.999). The analysis of binomial logistic regression model showed that fat-suppression T2 iso-signal ( OR=0.182, 95% CI: 0.036-0.914, P=0.039) and no ductal dilatation ( OR=0.198, 95% CI: 0.047-0.846, P=0.029) were the risk factors for breast malignant lesions. Conclusion:Breast cancer MRI findings of cluster ring enhancement, fat-suppression T2 iso-signal and no ductal dilatation are related risk factors for malignant breast lesions. MRI is helpful for early detection and diagnosis of breast lesions.

Central Nervous System Tuberculosis With Shower Like Pattern of Intracranial Tuberculomas in an Immunocompetent Patient.

Central nervous system tuberculosis (CNS TB), though comparatively uncommon as compared to other forms of extrapulmonary tuberculosis (TB), results in high morbidity and mortality. The symptoms are non-specific and of a progressive nature resulting in delayed diagnosis. We present a case of CNS TB that presented two months after the onset of symptoms. The patient's condition reached the point of being bedbound. On investigation, the widespread involvement of the brain with shower-like pattern of ring enhancing tuberculomas and associated tuberculous meningitis was found. This was a surprising finding considering the patient was immunocompetent. Contrast-enhanced magnetic resonance imaging showed lesions in midbrain, pons, medulla, thalamus, bilateral cerebellar hemispheres and bilateral cerebral hemispheres. Upon treatment initiation the patient responded well with resolution of all lesions.

[Fibrous Meningioma with Ring Enhancement in Cerebellopontine Angle Region:Report of One Case].

Fibrous meningioma is a common subtype of meningioma. Contrast-enhanced scan typically shows evident homogeneous enhancement,while ring enhancement has not been described. In this article,we report a case of fibrous meningioma with ring enhancement in cerebellopontine angle region.

Differentiation between Clinically Noninflammatory Granulomatous Lobular Mastitis and Noncalcified Ductal Carcinoma in situ Using Dynamic Contrast-Enhanced Magnetic Resonance Imaging.

INTRODUCTION: Challenges in differentiation between clinically noninflammatory granulomatous lobular mastitis (GLM) and noncalcified ductal carcinoma in situ (DCIS) remain. OBJECTIVE: To identify the dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) characteristics contributing to their differential diagnosis. METHODS: A total of 33 clinically noninflammatory GLM and 36 noncalcified DCIS were retrospectively analyzed in the study. Internal enhancement of a nonmass enhancement (NME) lesion was divided into clustered enhanced ring (absence/presence), and clustered enhanced ring (presence) was further classified as small and large ring based on the optimal cutoff value. The 5th Breast Imaging and Data System MRI descriptors were used for assessing the other DCE-MRI characteristics. Multivariate analysis including variables with significant differences in univariate analyses was conducted to identify the independent predictors. The discriminative abilities of different predictors and their combination were compared by area under the receiver-operating characteristic curves (AUCs). RESULTS: An NME lesion was seen more commonly in clinically noninflammatory GLM than in noncalcified DCIS (p = 0.003). DCE-MRI characteristics with significant differences in univariate analyses included NME size, clustered enhanced ring (absence/presence), ring size, initial increase and kinetic characteristics for the differentiation between these two entities presenting as NME lesion. Clustered enhanced ring (presence) was further classified as small (≤7 mm) or large ring (>7 mm). Multivariate analysis revealed that internal enhancement and initial increase were identified as significant independent predictors, and the AUC of their combination achieved the highest value of 0.867 (95% CI, 0.748-0.943). CONCLUSIONS: An NME lesion with a large ring is more highly suggestive of clinically noninflammatory GLM.

Fibrous Meningioma with Ring Enhancement in Cerebellopontine Angle Region:Report of One Case / 中国医学科学院学报

Fibrous meningioma is a common subtype of meningioma. Contrast-enhanced scan typically shows evident homogeneous enhancement,while ring enhancement has not been described. In this article,we report a case of fibrous meningioma with ring enhancement in cerebellopontine angle region.

Usefulness of Histogram-Profile Analysis in Ring-Enhancing Intracranial Lesions.

BACKGROUND: Several intracranial pathologies present as a ring-enhancing lesion on conventional magnetic resonance imaging (MRI), creating diagnostic difficulty. We studied the characteristics of the anatomical border of gadolinium enhancement on T1-weighted imaging (WI) and hypointensity on T2WI to employ a simple technique of histogram-profile analysis of MRI for differentiation of various ring-enhancing intracranial lesions. METHODS: After approval from the institutional review board, preoperative MRI (T2WI, postcontrast T1WI) scans were analyzed retrospectively in 18 patients with histologically confirmed brain abscess, 66 glioblastomas, 46 brain-metastases, and 16 tumefactive multiple sclerosis (MS). T2WI and postcontrast T1WI were overlapped, and histogram-profile analysis was performed with in-house image-fusion software. The pattern of differential-peaks in histogram-profile was assessed visually. Kaplan-Meier survival analysis incorporating histogram-profile patterns was performed in patients with glioblastoma. RESULTS: The histogram-profile study revealed 4 distinct patterns. Pattern 1 showed no differential T2-hypointensity trough, pattern 2 had T2-hypointensity trough inside, whereas pattern 3 had T2-hypointensity trough overlapping the enhanced margin. Pattern 4 had T2-hypointensity trough immediately external to the enhanced margin. Pattern 1 was specific for tumefactive MS (93.3%), whereas pattern 4 was specific for glioblastoma (40.7%). Pattern 4 glioblastoma was subdivided into rim (T2-hypointensity ≥50% of circumference of contrast-enhanced tumor) and arc (T2-hypointensity <50% of circumference of contrast-enhanced tumor). Pattern 4 glioblastoma was further subdivided into group A (edema: T2-hyperintensity ≥50% of circumference of contrast-enhanced tumor) and group B (less edema: T2-hyperintensity <50% of circumference of contrast-enhanced tumor). Patients with pattern 3 glioblastoma (37.6%) had better survival compared with others (P = 0.0341) and pattern 4B had decreased survival compared with pattern 4A (P = 0.0001) and others (P = 0.0003). CONCLUSIONS: Tumefactive MS and a subset of glioblastomas show specific patterns in histogram-profile analysis. The difference in anatomical border also determines difference in survival in glioblastoma. Histogram-profile analysis is a simple and efficient technique to differentiate these pathologies.

Toxoplasmic Encephalitis in an AIDS Patient with Normal CD4 Count: A Case Report.

Toxoplasmic encephalitis is a common presentation of Toxoplasma gondii infection of the central nervous system in the late stage in AIDS patients. A 40 yr old female patient was admitted to Razi Hospital of Qaemshahr City in north of Iran, in Nov 2015, with complaint of headache, blurring of vision, dysarthria and acute left-side hemiplegia and right-side ptosis. Magnetic Resonance Imaging (MRI) was performed with intravenous contrast that showed a ring enhancement lesion in the right basal ganglia showing toxoplasmic encephalitis. Anti-Toxoplasma IgG was positive. HIV antibody test was positive, as well. She was treated successfully with antiparasitic and Anti-HIV drugs and eventually was discharged from hospital. T. gondii infection is commonly detected by serologic tests. Even if in this patient, brain imaging is essential for suitable diagnosis and supervision, its results are not pathognomonic.

Canine histiocytic sarcoma presenting as a target lesion on brain magnetic resonance imaging and as a solitary pulmonary mass.

A 6-year-old spayed female miniature schnauzer presented with generalized seizures and progressive multifocal intracranial neurologic disease. Thoracic radiographs and computed tomography (CT) revealed a large solitary pulmonary mass within the right cranial lung lobe. On brain magnetic resonance imaging (MRI), a solitary intraparenchymal mass within the left piriform lobe had a "target" appearance on both pre- and postcontrast sequences. Cerebrospinal fluid was unremarkable and histopathology indicated both masses represented histiocytic sarcoma. This case represents an uncommonly reported MRI appearance of histiocytic sarcoma in the canine brain and a large, solitary-appearing pulmonary histiocytic sarcoma in the same dog.