Objectives: To identify the histologic and ultrastructural features of surgica lly excised subfoveal choroidal neovascular lesions from patients enrolled in th e Submacular Surgery Trials and to compare them with clinical data. Methods: Sur gically excised subfoveal choroidal neovascular lesions from patients enrolled i n the Submacular Surgery Trials group N trial (lesion predominantly choroidal ne ovascularization [CNV] with evidence of classic CNV from age-related macular de generation), group B trial (lesion predominantly hemorrhagic from age-relatedma cular degeneration), and groupHtrial (idiopathic subfoveal CNV or subfoveal CNV from ocular histoplasmosis syndrome) between October 1, 1999, and September 1, 2 001, were submitted to the pathology center. The lesion growth pattern (subretin al pigment epithelial [sub-RPE], subretinal, combined, or indeterminate) and th e cellular and extracellular constituents were classified independently. Demogra phic, clinical, and fluorescein angiographic characteristics of patients, eyes, and lesions, respectively, were compared with the pathologic features. Results: Of 269 patients assigned to surgery during the 24 months that pathologic specime nswere collected, surgical specimens from study eyes of 199 were submitted to th e pathology center. Of the 199 routine histologie specimens processed, 144 (72% ) were classified as CNV, 51 (26%) as fibrocellular tissue, and 4 (2%) as hemo rrhage. The median specimen size was smaller in group H (932 X 208 μm) than in groups N (1980 X 325 μm) and B (1800 X 395 μm). The CNV growth pattern was det ermined in 91 (46%) of 199 specimens. Of 159 group N and group B lesions, 76 (4 8%) had an indeterminate growth pattern, 28 (18%) had a sub-RPE growth patter n, and 33 (21%) had sub-RPE and subretinal growth patterns. Of 40 group H lesi ons, 32 (80%) had an indeterminate growth pattern, 7 (18%) had a subretinal gr owth pattern, and 1 (2%) had a combined sub-RPE and subretinal pattern. Based on electron microscopy, the most common cellular lesion components were RPE, mac rophages, erythrocytes, fibrocytes, and vascular endothelium; the most common ex tracellular components were 24-nm collagen and fibrin. Basal laminar and linear deposits were found in 80%(40/ 50) and 16%(8/49) of group N specimens, 66%(4 3/65) and 5%(3/65) of group B specimens, and 8%(2/26) and 0%(0/26) of group H specimens, respectively. Conclusions: Most surgically excised subfoveal specime ns had evidence of CNV or tissue associated with CNV. The constituents in CNV we re consistent with granulation tissue proliferation. The presence of basal depos its in surgically excised specimens suggested a clinical diagnosis of agerelated macular degeneration, even when blood was the predominant component of the lesion. Correlation of growth patterns above or below the RPE with fluoresc ein angiographic patterns of classic or occult CNV was limited because most spec imens had insufficient material to determine these patterns. Objectives: To identify the histologic and ultrastructural features of surgica lly excised subfoveal choroidal neovascular lesions from patients enrolled in th e Submacular Surgery Trials and to compare them with clinical data. Methods: Sur gically excised subfoveal choroidal neovascular lesions from patients enrolled in the Submacular Surgery Trials group N trial (lesion predominantly choroidal neovascularization [CNV] with evidence of classic CNV from age-related macular degeneration, group B trial (lesion predominantly hemorrhagic from age-related ma cular degeneration), and group Htrial (idiopathic subfoveal CNV or subfoveal The lesion growth pattern (subretin al pigment epithelial [sub-RPE], subretinal, combined, or indeterminate) and th ecellular and extracellular constituents were classified independently. Demogra phic, clinical, and fluorescein an giographic characteristics of patients, eyes, and lesions, respectively, were compared with the pathologic features. Results: Of 269 patients assigned to surgery during the 24 months that pathologic specime nswere collected, surgical specimens from study eyes of 199 were submitted to e pathology Of the 199 routine histologie specimens processed, 144 (72%) were classified as CNV, 51 (26%) as fibrocellular tissue, and 4 (2%) as hemo rhage. The median specimen size was smaller in group H The CNV growth pattern was detached in 91 (46%) of 199 specimens. Of 159 group N and group B lesions, 76 (X 208 μm) than in groups N (1980 × 325 μm) and B (40%) had an indeterminate growth pattern, 28 (18%) had a sub-RPE growth patter n, and 33 (21%) had sub-RPE and subretinal growth patterns. %) had an indeterminate growth pattern, 7 (18%) had a subretinal gr owth pattern, and 1 (2%) had a combined sub-RPE and subretinal pattern. Base d on electron microscopy, the most common cellular lesion components were RPE, mac rophages, erythrocytes, fibrocytes, and vascular endothelium; the most common ex tracellular components were 24-nm collagen and fibrin. 66% (4 3/65) and 5% (3/65) of group B specimens, and 8% (2/26) and 0% (0/50) and 16% (8/49) / 26) of group H specimens, respectively. Conclusions: Most surgically excised subfoveal specime ns had evidence of CNV or tissue associated with CNV. The constituents in CNV we re consistent with granulation tissue proliferation. The presence of basal depos its in surgically excised specimens suggested a clinical diagnosis of agerelated macular degeneration, even when blood was the predominant component of the lesion. Correlation of growth patterns above or below the RPE with fluorescein angiographic patterns of classic or occult CNV was limited because most spec imens had insufficient material to determine thes e patterns.