RESUMEN
AIM: To identify clinical factors associated with secondary elevated intraocular pressure (IOP) in eyes with iris malignant melanoma METHODS: A retrospective case series of 169 consecutive patients with microscopically confirmed iris malignant melanoma. The main outcome measure was the presence of tumour induced secondary elevated IOP. Cox proportional regression models were used to calculate the relation of clinical features to elevated IOP. RESULTS: Of 169 patients with microscopically proved iris melanoma, 50 (30%) presented with tumour induced secondary elevated IOP. The mean pressure in those eyes with elevated IOP at diagnosis was 33 mm Hg (median 31 mm Hg, range 23-65 mm Hg). The tumour configuration was nodular in 23 (46%) and diffuse in 27 (54%) with a mean base dimension of 7.4 mm and thickness of 2.0 mm. Invasion of the angle structures by melanoma seeds was visible for a mean of 7 clock hours (median 7, range 0-12 clock hours). The mechanism of elevated IOP was judged to be outflow obstruction from tumour invasion into the trabecular meshwork. There were no cases of neovascular glaucoma. The tumour was ultimately managed with enucleation in 30 patients (60%), local resection (iridectomy, iridocyclectomy, or iridocyclogoniectomy) in 11 (22%), and plaque radiotherapy in five (10%). In four cases (8%), observation of cytologically low grade tumour was the patient's preference. Using multivariate analysis, the clinical factors at initial evaluation associated with tumour induced secondary elevated IOP from iris melanoma included increasing extent of tumour seeding in the anterior chamber angle (p=0.01) and poor visual acuity at presentation (p=0.02). CONCLUSIONS: Microscopically confirmed iris melanoma demonstrates tumour related elevated IOP in 30% cases at the time of presentation, usually secondary to tumour involvement of the trabecular meshwork obstructing aqueous outflow. Enucleation is necessary in the majority of these patients (60%) as opposed to those cases without elevated intraocular pressure (18%).
Asunto(s)
Neoplasias del Iris/complicaciones , Melanoma/complicaciones , Hipertensión Ocular/etiología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Enucleación del Ojo/métodos , Femenino , Humanos , Neoplasias del Iris/patología , Neoplasias del Iris/terapia , Masculino , Melanoma/patología , Melanoma/terapia , Persona de Mediana Edad , Análisis Multivariante , Siembra Neoplásica , Hipertensión Ocular/patología , Hipertensión Ocular/terapia , Modelos de Riesgos Proporcionales , Estudios Retrospectivos , Factores de Riesgo , Malla Trabecular , Agudeza VisualRESUMEN
OBJECTIVE: To identify risk factors that predict distant metastases of iris malignant melanoma. DESIGN: Retrospective case series. PARTICIPANTS: The participants included 169 consecutive patients with microscopically confirmed iris malignant melanoma managed on the Oncology Service at Wills Eye Hospital between 1974 and 1999. MAIN OUTCOME MEASURES: The main outcome measure was the development of distant tumor metastasis. Cox proportional regression models were used to calculate the risk of eventual metastatic spread. RESULTS: Of 1054 patients referred with suspicious iris melanocytic tumors (rule out malignant melanoma) over a 25-year period, 169 patients (16%) had microscopically proven iris melanoma, and the remainder (84%) had clinically diagnosed iris nevus. Of the patients with iris melanoma, the mean age at the time of diagnosis was 43 years (median, 45 years; range, 1-90 years). All patients were Caucasian. The mean tumor base was 6 mm (median, 5 mm; range, 1-17 mm), and mean tumor thickness was 2 mm (median, 2 mm; range, 1-4 mm). The mean number of clock hours of tumor involvement in the iris was four, tumor seeding on the iris was four, and tumor seeding into the anterior chamber angle was four. Extraocular extension was present in 10 eyes (6%). The tumor management consisted of local resection (iridectomy, iridocyclectomy, or iridocyclogoniectomy) in 102 patients (60%), enucleation in 51 (30%), plaque radiotherapy in 9 (5%), and observation in 7 patients (4%). Metastasis developed in nine patients (5%). Using Kaplan-Meier life table analysis, metastasis was found in 3% of patients at 5 years, 5% at 10 years, and 10% at 20 years. The clinical factors at initial evaluation predictive of eventual metastasis from iris melanoma included increasing age at diagnosis (P = 0.03), elevated intraocular pressure (P = 0.03), posterior tumor margin at angle or iris root (versus midzone) (P = 0.02), extraocular extension (P: = 0.02), and prior surgical treatment of the tumor elsewhere before referral (versus observation) (P = 0.006). The method of management (resection, radiotherapy, or enucleation) did not have an impact on metastasis. CONCLUSIONS: Microscopically confirmed iris melanoma demonstrates distant metastasis in 5% of patients at 10 years follow-up. Metastases are more likely to develop in those patients who are older and show tumor features of iris root/angle location with elevated intraocular pressure and extraocular extension.