Role of apparent diffusion map in the evaluation of retinoblastoma.

PURPOSE: This study aimed to analyze the association between magnetic resonance imaging apparent diffusion coefficient map value and histopathological differentiation in patients who underwent eye enucleation due to retinoblastomas. METHODS: An observational chart review study of patients with retinoblastoma that had histopathology of the lesion and orbit magnetic resonance imaging with apparent diffusion coefficient analysis at Hospital de Clínicas de Porto Alegre between November 2013 and November 2016 was performed. The histopathology was reviewed after enucleation. To analyze the difference in apparent diffusion coefficient values between the two major histopathological prognostic groups, Student's t-test was used for the two groups. All statistical analyses were performed using SPSS version 19.0 for Microsoft Windows (SPSS, Inc., Chicago, IL, USA). Our institutional review board approved this retrospective study without obtaining informed consent. RESULTS: Thirteen children were evaluated, and only eight underwent eye enucleation and were included in the analysis. The others were treated with photocoagulation, embolization, radiotherapy, and chemotherapy and were excluded due to the lack of histopathological results. When compared with histopathology, magnetic resonance imaging demonstrated 100% accuracy in retinoblastoma diagnosis. Optic nerve invasion detection on magnetic resonance imaging showed a 66.6% sensitivity and 80.0% specificity. Positive and negative predictive values were 66.6% and 80.0%, respectively, with an accuracy of 75%. In addition, the mean apparent diffusion coefficient of the eight eyes was 0.615 × 103 mm2/s. The mean apparent diffusion coefficient value of poorly or undifferentiated retinoblastoma and differentiated tumors were 0.520 × 103 mm2/s and 0.774 × 103 mm2/s, respectively. CONCLUSION: This study revealed that magnetic resonance imaging is useful in the diagnosis of retinoblastoma and detection of optic nerve infiltration, with a sensitivity of 66.6% and specificity of 80%. Our results also showed lower apparent diffusion coefficient values in poorly differentiated retinoblastomas with a mean of 0.520 × 103 mm2/s, whereas in well and moderately differentiated, the mean was 0.774 × 103 mm2/s.

Role of apparent diffusion map in the evaluation of retinoblastoma

ABSTRACT Purpose: This study aimed to analyze the association between magnetic resonance imaging apparent diffusion coefficient map value and histopathological differentiation in patients who underwent eye enucleation due to retinoblastomas. Methods: An observational chart review study of patients with retinoblastoma that had histopathology of the lesion and orbit magnetic resonance imaging with apparent diffusion coefficient analysis at Hospital de Clínicas de Porto Alegre between November 2013 and November 2016 was performed. The histopathology was reviewed after enucleation. To analyze the difference in apparent diffusion coefficient values between the two major histopathological prognostic groups, Student's t-test was used for the two groups. All statistical analyses were performed using SPSS version 19.0 for Microsoft Windows (SPSS, Inc., Chicago, IL, USA). Our institutional review board approved this retrospective study without obtaining informed consent. Results: Thirteen children were evaluated, and only eight underwent eye enucleation and were included in the analysis. The others were treated with photocoagulation, embolization, radiotherapy, and chemotherapy and were excluded due to the lack of histopathological results. When compared with histopathology, magnetic resonance imaging demonstrated 100% accuracy in retinoblastoma diagnosis. Optic nerve invasion detection on magnetic resonance imaging showed a 66.6% sensitivity and 80.0% specificity. Positive and negative predictive values were 66.6% and 80.0%, respectively, with an accuracy of 75%. In addition, the mean apparent diffusion coefficient of the eight eyes was 0.615 × 103 mm2/s. The mean apparent diffusion coefficient value of poorly or undifferentiated retinoblastoma and differentiated tumors were 0.520 × 103 mm2/s and 0.774 × 103 mm2/s, respectively. Conclusion: This study revealed that magnetic resonance imaging is useful in the diagnosis of retinoblastoma and detection of optic nerve infiltration, with a sensitivity of 66.6% and specificity of 80%. Our results also showed lower apparent diffusion coefficient values in poorly differentiated retinoblastomas with a mean of 0.520 × 103 mm2/s, whereas in well and moderately differentiated, the mean was 0.774 × 103 mm2/s.

Xanthogranulomatous colloid cyst: Radiologic- pathologic correlation and diagnostic difficulties.

BACKGROUND: Despite colloid cyst in the third ventricle is a very usual cause of hydrocephalus, its xanthogranulomatous variant is rare. The most important differential diagnosis is the third ventricular craniopharyngioma. To the best of the authors' knowledge, there have been few cases of xanthogranulomatous variant colloid cysts reported in the English literature. CASE DESCRIPTION: A 77-year-old white woman presented with headaches, memory loss, and abnormal gait for the past 4 months. Magnetic resonance imaging revealed a solid cystic lesion measuring 3.0 cm×2.8 cm×2.9 cm located inside the anterior portion of the third ventricle causing obstructive hydrocephalus. The posterior portion of the lesion was predominantly solid and hypointense on T2 and T1, with areas of post- contrast enhancement, and the anterior portion was predominantly cystic with both hyper- and hypointense areas on T1 and T2, with no suppression on fluid-attenuated inversion recovery and no restriction to diffusion. The patient underwent a left frontal craniotomy with pterional approach, and the lesion was removed microsurgically. CONCLUSION: Xanthogranulomatous reaction is rarely described in colloid cysts, which happens as a response to desquamation of epithelial lining, subsequent lipid accumulation, and as tissue inflammatory response to intracystic hemorrhage. Microsurgical resection is the treatment of choice. As compared to the plain colloid cyst, these lesions are difficult to fully excise as the inflammatory reaction to the xanthomatous material leads to adhesions to adjacent structures; therefore, the aspiration of cystic contents without spillage is advisable to achieve maximal resection of cyst walls.