Chapters authored
Uses of Radiological Imaging in Retinoblastoma
Retinoblastoma is the most common primary ocular malignancy in children. Diagnosing retinoblastoma relies mainly on the clinical appearance of the lesion and not on histological description. Although histology still remains the gold standard in evaluation of tumor extension and progression risk factor, a tumor biopsy carries high risk of dissemination and is difficult to obtain. Retinoblastoma has characteristic clinical features of creamy-white mass associated with subretinal fluids and may be accompanied by retinal detachment and vitreous seeding. There are many factors contributing to metastatic risk factors like postlaminar optic nerve infiltration, scleral and choroidal invasion, and peribulbar fat invasion. Ancillary testing is necessary for any patient with a suspected retinoblastoma to assess the dimensions of the tumor as well as the tumor extension. An ultrasonography (B scan) will show the mass dimensions as well as the hyperechoic calcifications, which are commonly present with retinoblastoma. CT scan is not the modality of choice for diagnosis of retinoblastoma in children because of the radiation exposure. Magnetic resonance imaging is considered the examination of choice to assess the tumor extension as it has high soft tissue contrast. The use of MRI changed the accuracy of assessing metastatic risk factors as the results yielded before and after the use of MRI differed. This chapter will address the use of radiological imaging in retinoblastoma defining diagnostic characteristics and identifying parameters of metastatic risk factor assessment. This chapter will also include evidence-based review on the efficacy of radiological imaging of retinoblastoma and its impact on the choice of treatment and disease prognosis.
Part of the book: Retinoblastoma
Periocular Hemangioma: Clinicopathological Aspects
Hemangiomas are pathologically considered to be developmental hamartomatous lesions. In the periocular region, capillary hemangioma is commonly encountered in infants and children, and it is of particular importance because of its critical location if involving the eyelid with obstruction of the visual axis. In this chapter, we aim to briefly discuss the pathogenesis and etiology of such lesions, describe the histopathological features, and the diagnostic immunohistochemical stains used, with differentiating features between infantile hemangioma and capillary hemangioma in adults. In the periocular region, the clinical appearance and manifestations depend on three primary locations of the hemangioma: the superficial, subcutaneous, and deep orbital hemangiomas. Treatment options are similar to hemangioma elsewhere, however, as mentioned above, early treatment may be advocated to avoid developing amblyopia (lazy eye) because of visual deprivation or obstruction. The most used therapy in the periocular region is beta-blockers, either orally or locally. Intralesional steroids and sclerosing agents may also be used. Surgical intervention is reserved for deep orbital-selected lesions.
Part of the book: Common Childhood Diseases - Diagnosis, Prevention and Management [Working title]