Pulmonary Adenocarcinoma Metastatic to the Choroid Diagnosed by Biopsy of an Extrascleral Nodule

Abstract

Purpose/background: To report a patient with orbital extension of a choroidal metastasis produced by a pulmonary adenocarcinoma which was diagnosed by biopsy of the extrascleral nodule.

Methods: Clinical history and imaging studies (including fundus photography, autofluorescence, fluorescein angiography, B-scan, and orbital MRI) were reviewed along with histopathologic and immunohistochemical studies.

Results: A 60-year-old woman presented with decreased vision in the right eye. Fundus examination revealed a leopard-spotted choroidal lesion and associated serous retinal detachment. Imaging disclosed an enhancing orbital lesion abutting the sclera near the choroidal mass, which had spread outside of the eye. Histopathology revealed lumen-forming cells elaborating mucin. The cells were immunohistochemically positive for epithelial membrane antigen, thyroid transcription factor 1, and cytokeratin 7 and negative for cytokeratin 20. This was consistent with a pulmonary adenocarcinoma. Widespread metastases were subsequently found.

Conclusions: This is the first detailed case report of a successful biopsy of the orbital extension of an essentially posterior intraocular tumor. Such a maneuver permits a much more generous tissue sample than a needle biopsy. In the current case, a large tissue sample provided the basis for complete immunohistochemical evaluation, leading to the diagnosis of an intraocular metastatic mucin-producing adenocarcinoma of lung origin.

Keywords: Choroid; Immunohistochemistry; Lung carcinoma; Metastasis; Orbit.

Fig. 1.

Radiographic features of a patient with metastatic pulmonary adenocarcinoma to the choroid and orbit. a T1-weighted MRI in the axial projection discloses a crescent-shaped, well-circumscribed inferolateral orbital mass tightly adherent to the globe with adjacent choroidal thickening (arrow). b Positron emission tomography scan showing multiple areas of FDG avidity in the lung, hilum, orbit, peritoneum, and bones.

Fig. 2.

Clinical photography of a patient with metastatic pulmonary adenocarcinoma to the choroid and orbit. Wide-field pseudo-color fundus image of the right eye. a An orange, leopard-spotted choroidal lesion occupies much of the nasal and inferonasal retina. Arrowheads denote a subtle color change from the border of subretinal fluid. Wide-field autofluoresence image of the right eye. b Areas of retinal pigment epithelial (RPE) hypertrophy are hyperfluorescent secondary to lipofuscin accumulation, alternating with hypofluoresence in areas of RPE loss. A subtle hyperfluoresence correlates with the presence of subretinal fluid (arrowheads). Wide-field fluorescein angiogram. c In the area of the tumor, there is a pinpoint and lobular hyperfluorescent pattern that remains constant from the mid-stage of the angiogram without change in later frames. In the periphery (arrows), vascular leakage secondary to ischemia from chronic serous retinal detachment can be seen. B-Scan. d Nasal transverse B-scan of the right eye. The curved arrow shows the retinal detachment. The two linear segments through the posterior eye wall into the orbit denote choroidal thickening (yellow), the sclera (purple), and intraconal mass (green). The arrowhead is at the 4:30 meridian, showing a discontinuity in the posterior sclera, possibly a dilated emissary vein.

Fig. 3.

Histopathologic and immunohistochemical features of metastatic lung adenocarcinoma to the choroid and orbit. a Patulous lumens are filled with mucus (M) as revealed in the orbital biopsy. b Small clusters of tumor cells with oval-to-round nuclei lacking pleomorphism possess a moderate amount of eosinophilic cytoplasm. Note the intervening fibrosclerotic stroma. c The Alcian blue stain highlights tumor cells with intracytoplasmic vacuoles containing mucus, as well as surrounding extracellular mucus. d Mucicarmine stain displaying intracytoplasmic red-staining mucus. e Cytokeratin 7 uniformly stains the tumor cells' cytoplasm. f Thyroid transcription factor 1 immunostains the nuclei of most of the tumor cells. a, b Hematoxylin and eosin, ×100, ×200. c Alcian blue, ×400. d Mucicarmine, ×600. e, f Immunoperoxidase reaction, diaminobenzine chromogen, hematoxylin counterstain, ×100, ×100.