CASE REPORTS
Subconjunctival spread of ciliary body melanoma after glaucoma filtering surgery: a clinicopathological case report Sylvia Pasternak,*† MD; Clélia M. Erwenne,‡ MD; Marcelo T. Nicolela,† MD
U
veal melanoma can lead to glaucoma by a variety of mechanisms: direct angle invasion by the tumour, release of pigment, melanomalytic glaucoma (defined as obstruction of the trabecular meshwork by macrophages containing melanin pigment), neovascular glaucoma and anterior displacement of the lens–iris diaphragm with angle closure. Angle invasion and release of pigment are the most common mechanisms of glaucoma in iris and ciliary body melanomas, whereas neovascular glaucoma is the main mechanism in choroidal melanomas.1 Special care should be taken in secondary glaucoma of unknown cause to rule out ciliary body melanoma, as these tumours can sometimes be hidden behind the iris but still lead to glaucoma. We describe a patient with a ciliary body melanoma with subconjunctival extension who had previously undergone a combined triple procedure (cataract extraction, intraocular lens implantation and trabeculectomy) following an acute glaucoma episode. The trabeculectomy site likely provided a route for the subconjunctival extension of the tumour.
CASE
REPORT
A 60-year-old white man was referred to the Ocular
From the Departments of *Pathology and of †Ophthalmology and Visual Sciences, Dalhousie University, Halifax, NS, and ‡the Department of Ophthalmology, Federal University of São Paulo, São Paulo, Brazil Originally received Jan. 29, 2004 Accepted for publication July 13, 2004 Correspondence to: Dr. Marcelo T. Nicolela, Eye Care Centre, 1278 Tower Rd., Halifax NS B3H 2Y9; fax (902) 473-2839;
[email protected] This article has been peer-reviewed. Can J Ophthalmol 2005;40:69–71
Oncology Service of a cancer hospital with suspected anterior uveal melanoma. One year earlier he had had an acute glaucoma episode in his right eye. He had presented elsewhere with acute onset of pain and decreased visual acuity in his right eye. The intraocular pressure (IOP) at presentation at that time was 70 mm Hg and 17 mm Hg in the right and left eyes respectively, and a presumed diagnosis of primary angle-closure glaucoma was made. The patient was initially treated with medical antiglaucoma therapy followed by laser iridotomy. Despite treatment, the IOP remained elevated, at about 40 mm Hg, and a significant cataract developed. The patient underwent an uneventful combined triple procedure (cataract extraction by phacoemulsification, implantation of an intraocular lens and trabeculectomy without the use of antimetabolites). He was lost to follow-up a few weeks after the procedure. One year later he returned to his original attending physician, who noted an intraocular pigmented mass and subconjunctival pigmented lesions, prompting referral to us. On examination, his best-corrected visual acuity was no light perception in the right eye and 20/40 in the left eye, and the IOP was 40 mm Hg and 17 mm Hg respectively. Slit-lamp examination of the right eye showed subconjunctival pigmented lesions in the superonasal portion, close to the limbus (Fig. 1). There was a nonfunctioning filtering bleb in the same area. One large and several smaller pigmented lesions were observed in the iris. The pupil was distorted, and an intraocular lens implant was present. Behind the iris, in the superonasal area, a large pigmented tumour was observed, probably arising from the ciliary body. Gonioscopy showed the superior and nasal regions of the angle to be occupied by the pigmented lesion. The remaining angle was open, with increased pigmentation and scattered posterior anterior synechiae. Fundus examination revealed the optic disc to be totally cupped; the retina was normal. Slit-lamp, gonioscopic and fundus examinations of the left eye were unremarkable.
Subconjunctival spread of melanoma—Pasternak et al
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Subconjunctival spread of melanoma—Pasternak et al
Fig. 1—External photograph, showing subconjunctival pigmented lesions in superonasal quadrant. The conjunctiva is heavily hyperemic, and the filtering bleb is nonfunctioning. Note also pigmented lesions in iris.
Fig. 2—Photomicrograph, showing ciliary body malignant melanoma extending into subconjunctival space through trabeculectomy site (arrow) (hematoxylin–eosin; magnification ×25).
A systemic evaluation, including determination of liver transaminase levels, abdominal ultrasonography, chest radiography and computed tomography of the chest and abdomen, did not disclose metastasis. After informed consent was obtained, the right eye was enucleated. Care was taken to open the conjunctiva about 8 mm behind the subconjunctival pigmented lesions. The affected conjunctiva was therefore removed en bloc with the eye. Cryotherapy was applied to the conjunctival margins. Gross examination showed a pigmented tumour occupying the superonasal region of the ciliary body. The tumour extended to the iris and subconjunctival space in the same area. Microscopic examination showed a malignant melanoma of the ciliary body of mixed spindle and epithelioid cell type extending to the iris. The tumour had grown through the sclerectomy of the filtering surgery, reaching the subconjunctival space (Fig. 2). The cornea was unremarkable. The retina showed atrophy of the internal layers with loss of ganglion cells, consistent with long-standing glaucoma. The optic disc was totally cupped. The patient had an uneventful postoperative course. At the time of the last examination, 1 year after enucleation, a similar systemic evaluation showed no signs of local recurrence or systemic metastasis.
reported a much lower prevalence of glaucoma in patients with uveal melanoma: IOP elevation was observed in 17% of those with ciliary body melanoma, 7% of those with iris melanoma and 2% of those with choroidal melanoma. This apparent decrease in the prevalence of glaucoma probably reflects the widespread use of indirect ophthalmoscopy, leading to early recognition and treatment of uveal melanomas. Ciliary body melanomas, however, can grow significantly before producing symptoms or being detectable by slit-lamp examination or indirect ophthalmoscopy, and may cause elevation of IOP as the first manifestation of the disease. There are several possible mechanisms for the IOP elevation in patients with uveal melanoma. In a clinical retrospective study of patients presenting to the Oncology Service of Wills Eye Hospital, Philadelphia, Shields and colleagues1 found that the most frequent causes of glaucoma in those with iris or ciliary body melanoma were tumour invasion of the angle and release of pigment. Yanoff,3 however, in a histopathological review of enucleated eyes with uveal melanoma, reported that the most common cause of glaucoma in cases of iris or ciliary body melanoma was posterior synechiae leading to iris bombé and secondary angle closure. In our case, it is difficult to speculate about the possible cause of the elevated IOP at the time of initial presentation, since the patient was treated elsewhere. According to information collected from the original attending physician and our own examination at the time of referral, 1 year after the combined triple procedure, we believe that the most likely mechanism of the elevated IOP was tumour invasion of the angle and pigment release, which were not noticed initially. It is also possible that anterior displacement of the lens–iris diaphragm had occurred, leading to acute secondary
COMMENTS This case highlights the importance of investigating all cases of secondary glaucoma to rule out the presence of intraocular tumour as glaucoma can, rarely, be the initial presentation of undiagnosed uveal melanoma.2 Glaucoma has been reported in up to 20% to 57% of patients with uveal melanoma, with a particularly high prevalence in those with choroidal melanoma.3–5 More recently, Shields and colleagues1
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angle-closure glaucoma, which eventually settled following lens removal and trabeculectomy. Peculiar to our case was subconjunctival spread of the melanoma, which likely occurred through the trabeculectomy site. This feature highlights the potential danger of performing a glaucoma filtering procedure in an eye with uveal melanoma. There are sporadic reports of such procedures in eyes with uveal melanoma. Singer and associates6 described a patient in whom systemic metastases and local recurrence were identified 2 years after enucleation of an eye in which glaucoma surgery had previously been performed. The authors speculated whether the bad clinical course was associated with the glaucoma filtering procedure. Grossniklaus and coworkers7 described a patient in whom an iris pigmented tumour developed after trabeculectomy. Histopathological examination showed iris melanoma and seeding of melanoma cells into the conjunctival filtering bleb. Bhorade and colleagues8 reported a case of subconjunctival extension of a ciliary body melanocytoma in an eye that had undergone trabeculectomy. Extrascleral extension of anterior uveal melanoma can also occur through anterior emissary veins in the absence of any surgery.9 Our case illustrates the importance of ruling out an intraocular tumour in patients presenting with secondary glaucoma of unknown cause. Ocular ultrasonography and ultrasound biomicroscopy are useful diagnostic tools in these patients and should be performed. It is particularly important to look for ciliary body tumours, as they are more frequently associated with elevated IOP and can be difficult to diagnose. Our case and the few others previously reported in the literature suggest that glaucoma filtering surgery increases the risk of extraocular spread of anterior uveal malignant melanoma.
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Shields CL, Shields JA, Shields MB, Augsburger JJ. Prevalence and mechanisms of secondary intraocular pressure elevation in eyes with intraocular tumors. Ophthalmology 1987;94:839–46. Escalona-Benz E, Benz MS, Briggs JW, Budenz DL, Parrish RK, Murray TG. Uveal melanoma presenting as acute angle-closure glaucoma: report of two cases. Am J Ophthalmol 2003;136:756–8. Yanoff M. Mechanisms of glaucoma in eyes with uveal malignant melanomas. Int Ophthalmol Clin 1972;12:51–62. Marshall CD. On tension in cases of intra-ocular tumour. Trans Ophthalmol Soc U K 1896;16:155–70. Martin-Jones JD. Uveal sarcomata. Br J Ophthalmol 1946;11:1–94. Singer PR, Krupin T, Smith ME, Becker B. Recurrent orbital and metastatic melanoma in a patient undergoing previous glaucoma surgery. Am J Ophthalmol 1979;87:766–8. Grossniklaus HE, Brown RH, Stulting RD, Blasberg RD. Iris melanoma seeding through a trabeculectomy site. Arch Ophthalmol 1990;108:1287–90. Bhorade AM, Edward DP, Goldstein DA. Ciliary body melanocytoma with anterior segment pigment dispersion and elevated intraocular pressure. J Glaucoma 1999;8:129–33. McLean IW. Uveal nevi and malignant melanomas. In: Spencer WH, editor. Ophthalmic pathology: an atlas and textbook. 4th ed. Philadelphia: W.B. Saunders Company; 1996. p. 2121–217.
Key words: uveal melanoma, glaucoma, trabeculectomy, ciliary body, surgical complications
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