Microcirculation patterns other than loops and networks in choroidal and ciliary body melanomas

Purpose: To provide ophthalmologists and pathologists with expanded criteri a for separating patients at high: risk of metastatic melanoma from those a t low risk on the basis of microcirculation patterns in choroidal and cilia ry body melanomas. Design. Tissue culture studies and observational case series. Participants: The pattern-forming ability of four uveal melanoma cell lines of varying degrees of aggressive behavior was studied in vitro. Histologic sections of 234 eyes removed for choroidal or ciliary body melanoma were s tudied for the presence of microcirculation patterns. Methods: The study was divided into two phases: the study of histologic sec tions of eyes removed for choroidal and ciliary body melanomas and observat ions on the in vitro behavior of cultured melanoma cells of varying degrees of invasive behavior. The presence or absence of each of nine microcircula tion patterns was recorded from tissue sections, and interrelationships bet ween different patterns were explored statistically. In vitro reconstitutio n of patterns and a study of the interrelationships of patterns in histolog ic sections was carried out. In the in vitro studies, uveal melanoma cell l ines of varying degrees of aggressive potential were cultured to observe th e development of architectural patterns other than loops and networks. Main Outcome Measures: In histologic studies, the outcome measure was the c onditional probability of detecting loops or networks given the presence or absence of other patterns positive for periodic acid-Schiff. For tissue cu lture studies, the outcome measure was either the development or lack of de velopment of patterns of different shapes in vitro. Results: Histologic studies disclosed that given the presence of arcs witho ut or with branching in a tissue section, it is likely that loops or networ ks will be detected in the same section plane, suggesting that the producti on of these patterns by aggressive tumor cells reflects a spectrum of archi tectural potential, In vitro studies confirmed this hypothesis by revealing that highly aggressive and metastatic uveal melanoma cell lines, but not p oorly aggressive tumor cell lines, generated parallel channels with and wit hout crosslinking and arcs with and without branching as well as loops and networks. Conclusions: The criteria for separating patients into low- and high-risk c ategories for metastasis from uveal melanoma should be expanded to include patterns other than loops or networks. In both the pathology laboratory as well as in a clinical setting, the detection of arcs or arcs with branching and parallel channels should prompt a careful search for loops and network s and for crosslinking parallel channels, respectively. Ophthalmology 2001; 108:996-1001 (C) 2001 by the American Academy of Ophthalmology.