Chapter 6

Secondary Orbital Tumors Extending from Ocular or Periorbital Structures

Roman Shinder and Bita Esmaeli

Abstract Secondary orbital tumors are those that extend into the orbit from contiguous structures, such as the globe, eyelids, lacrimal sac, bone, sinuses, nasopharynx, and brain. They account for approximately one-quarter of orbital neoplasia. A computed tomography or magnetic resonance imaging scan is used to investigate suspicious lesions, and biopsy is typically undertaken to establish a tissue diagnosis and help construct a treatment plan. Prognosis is often poor owing to significant extension of the tumor at presentation.

6.1 Tumors of Intraocular and Ocular Adnexal Origin

6.1.1 Eyelid Tumors

Eyelid cancers such as basal cell carcinoma, squamous cell carcinoma, and sebaceous gland carcinoma can invade the orbit if the primary tumor is left untreated; such cancers can also appear in the orbit as recurrent disease. Basal cell carcinoma is the most common eyelid cancer to invade the orbit, and basal cell carcinoma arising from the medial canthus is particularly prone to orbital invasion. Ocular adnexal cancers represent the most common indication for orbital exenteration [1], and in some cases, exenteration must be followed by adjuvant radiation therapy. In a large case series reported by Günalp et al. [1], 25% of basal cell carcinomas requiring exenteration represented recurrent disease. The mortality rates after orbital exenteration due to causes related to basal and squamous cell carcinomas were 8 and 12%, respectively, with approximately 2-year follow-up [1].

R. Shinder (B)

Section of Ophthalmology, Department of Head and Neck Surgery, The University of Texas M.D. Anderson Cancer Center, Houston, TX, USA

e-mail: romanshinder@hotmail.com

Oncology Series 6, DOI 10.1007/978-1-4419-0374-7_6,

C Springer Science+Business Media, LLC 2011

6.1.2 Intraocular Tumors

Uveal melanoma and retinoblastoma are intraocular tumors that may display extrascleral spread into the orbit in advanced cases.

Microscopic extension through the sclera and episcleral emissary channels is estimated to be present in 10–40% of enucleated uveal melanoma specimens [2, 3]. Nevertheless, gross orbital extension, which may occur along the optic nerve, remains a rare event in patients with uveal melanoma [4–6]. Optic nerve extension of uveal melanoma is estimated to occur in only 0.6–3.7% of cases (Fig. 6.1) [6]. To decrease the likelihood of orbital recurrence, palliative orbital radiation therapy may be given in cases of uveal melanoma that exhibit microscopic episcleral or optic nerve extension. However, orbital radiation therapy does not reduce the risk of distant organ metastasis from hematogenous spread of uveal melanoma, which can be lethal.

In neglected or untreated cases, retinoblastoma can demonstrate extraocular spread into the orbit, not only through the optic nerve but also through the sclera. Orbital invasion via either route is a risk factor for metastasis. In retinoblastoma, optic nerve involvement is the most important risk factor for central nervous system metastasis [7–10], and extrascleral extension has been reported to be the most significant risk factor for distant metastasis, as the tumor gains access to the vascular and lymphatic channels outside the globe [7].

Treatment modalities for orbital involvement of retinoblastoma or uveal melanoma include combined-modality chemotherapy and radiation therapy and eyelid-sparing exenteration; the mortality rates in patients treated with such modalities are 90 and 71%, respectively [1]. When retinoblastoma cells are present at the cut end of an enucleated optic nerve, adjuvant chemotherapy together with orbital radiation therapy reduces the risk of metastasis [11–13].

Fig. 6.1 Magnetic resonance image of a left uveal melanoma with extension into the orbit. The patient has undergone enucleation. The uveal melanoma mass in the left orbit is pushing the orbital implant up