The role of endoscopic sinus surgery in the diagnosis and treatment of metastatic orbital carcinoid tumors

Ear, Nose & Throat Journal, March, 2007 by Roland Z. Gerencer, Uresh Patel, Charles Hunter, J. Timothy Heffernan

Abstract

Carcinoid tumor metastatic to the orbit is a rare occurrence. We report such a case in a patient with a carcinoid metastasis that was found in the medial rectus muscle. The diagnosis was established via a transnasal endoscopic approach. We also discuss the treatment of metastatic orbital carcinoid in the hope that we will increase awareness of the utility of transnasal endoscopy in facilitating both the diagnosis and treatment of posteromedial orbital pathology.

Introduction

Carcinoid tumors are slowly growing, potentially malignant neoplasms that arise from wherever endodermally derived neuroendocrine cells are found. The term carcinoid dates back to 1907, when Oberndorfer used it to describe a tumor whose cells exhibit a seemingly benign biologic behavior but are histologically similar to carcinoma cells. (1) It was not until several decades later that the malignant potential of these tumors became apparent.

Approximately 90% of carcinoid tumors originate in the gastrointestinal tract; other locations of particular interest to otolaryngologists include the middle ear, parotid gland, larynx, and thyroid gland. (2-5)

Orbital and ocular involvement by metastatic carcinoid is very rare. We describe a case in which the carcinoid tumor was metastatic to the medial rectus muscle. The diagnosis was made possible by endoscopic techniques. The purpose of this article is to increase awareness among otolaryngologists of the utility of the transnasal endoscopic approach in facilitating the diagnosis and treatment of posteromedial orbital pathology.

Case report

A 58-year-old woman presented to her ophthalmologist with a 6-week history of episodic vision loss in the fight eye and a 2-week history of increasing photophobia and right-sided retro-orbital pressure. Further inquiry revealed a 1-year history of fortification spectra across her visual field, and a 3-month history of paroxysmal vertex headaches radiating down the fight side of her head in the distribution of the ophthalmic and maxillary divisions of the ipsilateral trigeminal nerve. Her medical history was remarkable for metastatic carcinoid of the liver, which had been diagnosed 1 year earlier by liver biopsy. She had undergone cycles of cisplatin, mitomycin C, and doxorubicin intra-arterially to induce remission of her hepatic disease.

The patient was also experiencing episodic facial flushing and dyspnea suggestive of carcinoid syndrome, which provided a further impetus for a metastatic workup. The workup included a bone scan, echocardiogram, and an indium 111 ((111) In) octreotide scan. Radiolabeled octreotide is a somatostatin analog that is highly sensitive in detecting carcinoid tumors, and it identified an asymptomatic deposit in the lower lobe of the right lung, possibly indicating that this was the site of the primary tumor.

On ophthalmologic examination, the patient's visual acuity in the fight eye was 20/25, and the intraocular tension was normal. Restricted abduction was noted on the right, causing diplopia on lateral gaze. Fundoscopy revealed optic disk edema, but no afferent pupillary defect was seen. There was no ptosis or proptosis. Computed tomography (CT) of the orbit identified a 1.7 x 2.5-cm dumbbell-shaped mass in the right medial rectus muscle (figure 1). The mass extended to the orbital apex and displaced the optic nerve superiorly and laterally. Prominent scalloping of the lamina papyracea was visible, but there was no bony erosion or evidence of intracranial extension.

[FIGURE 1 OMITTED]

The patient's ophthalmic surgeon obtained a biopsy specimen via a right anterior orbitotomy. Unfortunately, not enough tissue was available to allow for a diagnosis, so the patient subsequently underwent a transnasal transethmoid endoscopic biopsy and limited orbital decompression (figure 2). Following a standard endoscopic middle maxillary antrostomy and total ethmoidectomy, the ipsilateral lamina papyracea was removed. The orbital periosteum was incised over the readily visible mass, and representative tumor samples were obtained.

[FIGURE 2 OMITTED]

Grossly, the tumor mass was pink-white, multilobular, soft, and friable. Infiltration of the medial rectus muscle fibers was readily apparent. Metastatic orbital carcinoid was diagnosed. Histologic examination revealed nests of small, cohesive cells with uniform nuclei, speckled chromatin, and indistinct or absent nucleoli typical of carcinoid tumors (figure 3). Immunostains demonstrated uniform cytoplasmic expression of synaptophysin and chromogranin, also characteristic of carcinoid tumors.

[FIGURE 3 OMITTED]

The patient's vision improved immediately after the procedure, only to progressively fade and become gradually darker over the following several weeks. Attempts to halt this progression with oral prednisone were unsuccessful, and repeat CT of the orbits revealed no change in the appearance of the mass. At 9 months' follow-up, the patient had completed 4,400 cGy of radiation to the right orbit, which produced a small decrease in the CT appearance of the tumor and mild clinical improvement in her sense of light perception. She was maintained on (111) In octreotide scanning to treat symptoms of associated carcinoid syndrome and cycles of palliative capecitabine chemotherapy. At 2-year follow-up, the patient was still alive with metastatic carcinoid.