Primary anorectal malignant melanoma: A clinical, radiology and pathology correlation

@#Introduction: Primary gastrointestinal melanomas are mucosal malignancies that arise from melanocytes in the oropharynx, rectum, and anus. Anorectal malignant melanoma (ARMM) are exceedingly rare, accounting for less than 1% of all melanomas, 0.1% of all rectal malignancies and 4% of anal malignancies. Diagnosis is frequently delayed as these lesions are often mistaken for haemorrhoids. Histological evaluation with special immunohistochemical stains is often necessary for definitive diagnosis. Due to the aggressive nature, 61% of patients with ARMM would already have lymph node involvement or distant metastases, by the time of diagnosis. Prognosis is usually poor with 5-year survival rate of <20%. We report a case of metastatic ARMM in an elderly lady who presented with symptoms and signs mimicking a haemorrhoid. Case Report: A 69-year-old lady presented with one year history of intermittent rectal bleed and an anorectal mass that was initially treated as haemorrhoid. Colonoscopy showed a hyperpigmented mass in the anorectal region which was confirmed as malignant melanoma on histopathological examination. Imaging with CT and MRI demonstrated locally advanced tumour with distant metastases to the liver and lung. Patient was referred for palliative management. Conclusion: ARMM is a rare malignancy and often presented with non-specific clinical signs. Diagnosis is frequently delayed without high index of suspicion. MRI pelvis is the imaging of choice to assess local extent of disease. Histologic evaluation with special immunohistochemical stains is often necessary for definitive diagnosis. Prognosis is poor despite surgical and chemotherapeutic interventions.

MRI Imaging Features of Meningioma

Meningiomas are the most common non glial extra axial primary brain tumors of the central nervous system (CNS), accounting for between 16 to 20% of all intracranial tumors. Aim: In this study we tried to describe typical and atypical locations and findings of intracranial meningiomas on MRI and also MRI features of meningiomas that differentiate from other extra axial lesions. Methods: Studied population was advised to undergo MRI investigations for confirmation of meningiomas and to differentiate from other extra axial tumors and CT suggested in few cases for confirmation of calcification and boney changes. All MR imaging were performed with 1.5T bravo MR imaging unit with standard protocol. In operated cases, MRI findings were correlated with intraoperative findings and histopathological diagnosis. Results: Majority of meningioma patients were observed in the age group of 51-70 years i.e., 24 (80%) out of 30 cases. The most common site of occurrence are the cerebral convexities, parasaggital location/falx, posterior fossa, sphenoid ridge, olfactory groove and others accounting for 33.3%, 20%. 20%, 10%, 6.7% and 10% respectively. 67% of meningiomas showed homogenous enhancement, 56% cases had dural tail sign, 40% meningioma cases observed with CSF cleft, 37% of cases showed mass effect on surrounding arteries, cranial nerves, ventricular system and brainstem noted in twelve cases. 33% of cases noticed with perilesional edema, 30% had calcifications, 20% hyperostosis, 13% sinus invasion and 10% were others such as haemorrhages, cystic or non enhancement areas. Conclusions: As Meningiomas are not an uncommon tumors, radiologists should be aware of different MRI characteristics and locations of meningiomal tumors, this will help to arrive at accurate diagnosis especially in atypical and misleading meningioma features.

Giant perivascular spaces: two case reports

Giant perivascular spaces or Virchow-Robin spaces (VRSs) are uniquely inherent developmental malformation and are generally lined by ependymal or leptomeningeal cells. The cerebral hemispheres with VRSs present multiple cysts of curvilinear, round, oval, or layered configuration, which have the same signal intensity as the cerebrospinal fluid (CSF) and represent extremely dilated VRSs. The cortex became extremely thin with a well-defined margin. Herein, we report two cases of true giant perivascular spaces and present a review of pertinent literature. A patient has multiple cysts in the unilateral and bilateral and has polycystic liver. The clinical presentation, image logical features, and diagnosis are discussed.

MRI Features and Site-specific Factors of Ischemic Changes in White Matter: A Retrospective Study / 华中科技大学学报（医学）（英德文版）

Brain magnetic resonance imaging (MRI) of the elderly often reveals white matter changes (WMCs) with substantial variability across individuals.Our study was designed to explore MRI features and site-specific factors of ischemic WMCs.Clinical data of consecutive patients diagnosed with ischemic cerebral vascular disease who had undergone brain MRI were collected and analyzed.Multi-logistic regression analysis comparing patients with mild versus severe WMCs was performed to detect independent associations.Analyses of variance (ANOVAs) were used to detect regionally specific differences in lesions.We found that lesion distribution differed significantly across five cerebral areas,with lesions being predominant in the frontal lobe and parieto-occipital area.To explore WMCs risk factors,after adjusting for gender,diabetes mellitus,and hypertension,only age (P＜0.01),creatinine (P=0.01),alkaline phosphatase (ALP) (P=0.01) and low-density lipoprotein cholesterol (LDL-C) (P=0.03) were found to be independently associated with severe WMCs.Age (P＜0.001) was strongly associated with WMCs in the frontal lobe while hypertension was independently related to lesions in the basal ganglia (P=0.048) or infratentorial area (P=0.016).In conclusion,MRI of WMCs showed that ischemic WMCs occurred mostly in the frontal lobe and parieto-occipital area.The infratentorial area was least affected by WMCs.Typically,age-related WMCs were observed in the frontal lobes,while hypertension-related WMCs tended to occur in the basal ganglia and infratentorial area.

MRI Features and Site-specific Factors of Ischemic Changes in White Matter: A Retrospective Study / 华中科技大学学报（医学）（英德文版）

Brain magnetic resonance imaging (MRI) of the elderly often reveals white matter changes (WMCs) with substantial variability across individuals.Our study was designed to explore MRI features and site-specific factors of ischemic WMCs.Clinical data of consecutive patients diagnosed with ischemic cerebral vascular disease who had undergone brain MRI were collected and analyzed.Multi-logistic regression analysis comparing patients with mild versus severe WMCs was performed to detect independent associations.Analyses of variance (ANOVAs) were used to detect regionally specific differences in lesions.We found that lesion distribution differed significantly across five cerebral areas,with lesions being predominant in the frontal lobe and parieto-occipital area.To explore WMCs risk factors,after adjusting for gender,diabetes mellitus,and hypertension,only age (P＜0.01),creatinine (P=0.01),alkaline phosphatase (ALP) (P=0.01) and low-density lipoprotein cholesterol (LDL-C) (P=0.03) were found to be independently associated with severe WMCs.Age (P＜0.001) was strongly associated with WMCs in the frontal lobe while hypertension was independently related to lesions in the basal ganglia (P=0.048) or infratentorial area (P=0.016).In conclusion,MRI of WMCs showed that ischemic WMCs occurred mostly in the frontal lobe and parieto-occipital area.The infratentorial area was least affected by WMCs.Typically,age-related WMCs were observed in the frontal lobes,while hypertension-related WMCs tended to occur in the basal ganglia and infratentorial area.

The Relationship between Preoperative MRI Characteristics and The Perioperative Outcomes of Microvas- cular Decompression in Primary Trigeminal Neuralgia / 中国神经精神疾病杂志

Objective To evaluate the relationship between preoperative MRI characteristics and the perioperative outcomes of microvascular decompression in primary trigeminal neuralgia. Methods To analyze the relationship between preoperative MRI characteristics and the perioperative outcomes in 103 primary trigeminal neuralgia patients with micro-vascular decompression in Nanfang Hospital. The MRI features such as the ratio of CPA area, TGN cross-sectional area and TGN length was evaluated together with the TGN oppression distance, the position of TGN, the position of basilar ar-tery and the type of offending vessel as well as the outocmes including complete disappearance, temporary remission and ineffectiveness. Results Univariate analysis showed that the oppression orientation (P=0.017), oppression distance (P<0.001), offending vascular type (P=0.016), TGN cross-sectional area ratio (P<0.001) were the influencing factors of periop-erative outcomes. Logistic regression analysis showed that the offending vascular type (P=0.002)and TGN cross-sectional area ratio (P=0.020) were the main predictive factors of perioperative outcomes of microvascular decompression. Conclu-sions Preoperative thin slice MRI scanning showed that the offending artery, non-atrophy nerve roots, far distance from op-pression point to brainstem may be the favorable factors of perioperative outcomes of microvascular decompression.