Imaging overview of ocular & orbital tumors
Himadri Sikhor Das
: J Clin Exp Oncol
Orbital tumors encompass different variety of lesions according to cell of origin. Careful evaluation of a patientâs history and examination along with modern high-resolution imaging studies provide the best information regarding the possible origin of an orbital lesion. Given the variety of structures within the relatively confined orbit, a systematic approach is necessary to understand the classification and imaging characteristics of orbital tumors. Orbital tumors are also divided anatomically into intraconal and extraconal depending on their relationship with the muscle cone. The muscle cone is formed by the extraocular recti muscles and their intermuscular septae, which separate the intraconal from the extraconal space. The muscle cone has a conical shape with the globe serving as the base and the optic canal as its apex. The diagnostic approach to tumor's of the orbit should focus on specific anatomical locations âthe globe, intraconal space, extraconal space, preseptal space, bony orbit, paranasal sinuses, lacrimal gland, optic nerve and globe. Useful features on CT are density including calcification and contrast enhancement, and on MRI the signal characteristics of the mass and contrast enhancement. As a general rule, benign tumors cause displacement and moulding of adjacent structures, whereas malignant lesions display an aggressive pattern of growth, destroying and obliterating the contours of surrounding structures. In this presentation, a general overview of morphology, pathological characteristics and imaging features of primary orbital tumors is discussed. Metastatic lesions are also briefly reviewed.
Himadri Sikhor Das, MBBS, MD is a radiologist from Guwahati, India with 15 years post MD experience with special interest in Neuro-Radiology, Head & Neck, Ocular/Orbital Radiology & Neuro-Ophthalmology. He is presently working as Consultant Radiologist and Executive Director, Matrix (Unit of Apace Imaging & Diagnostic Centre Pvt Ltd.) and Honorary Visiting Consultant & Thesis guide. He is Diplomate of National Board (DNB) Radiology at Institute of Neurosciences- GNRC Hospitals. He completed his MBBS in September ‘93, MD Radiology in February 1999 and Post Degree Fellowship in Neuroradiology in March 2000 followed by Senior Residency in the Department of Neuro-Radiology, AIIMS, New Delhi. He has many national and international publications & presentations and is also involved in many on-going national & international collaborative projects like Population based Indian Cancer Registry (Govt. of India) & the Digital Web Repository with MEDting (Spain). He also is active life member of many professional societies.