Case Presentation: This is a 37 yo F with Latent TB who presents with five days of worsening right eye vision loss. On further workup was found to have a right sided chorioretinal mass along with retinal detachment. CT Chest revealed bilateral lower lobe pulmonary nodules, largest being 1.5 cm on the right side. CT Abdomen/Pelvis revealed three liver lesions with possible peritoneal implants along with T-10 and a right proximal femur lesion. MRI of the brain did not show any parenchymal brain lesions. There was an initial percutaneous liver biopsy which was non-diagnostic but a second liver biopsy revealed adenocarcinoma from a lung primary with echinoderm microtubule-associated protein-like 4-anaplastic lymphoma kinase (EML4-ALK) fusion. The patient was subsequently started on treatment with an ALK-inhibitor called Alectinib. Given the unclear intraocular penetration of Alectininb the patient was also referred for radiation treatment to the right eye.
Discussion: Metastatic carcinoma to the eye is a rare occurrence but when it occurs the choroid is the most commonly affected area. The most frequent sites of origin of choroidal metastasis are breast, lung, unknown primary and skin melanomas. Our decision making process for pathology had to be re evaluated after our initial biopsy was indeterminate. We made the decision to keep the patient inpatient while awaiting preliminary pathology results which turned out to the be the right decision given inadequate sampling on the first attempt. Lung adenocarcinoma is the most common pathology associated with non-smokers as in our patient
Approximately 5% of Non-small Cell Lung Cancer (NSCLC) patients have an inversion in chromosome 2 in the EML4 gene with the ALK gene. Those with this genetic abnormality have tumors that are highly sensitive to ALK tyrosine kinase inhibitors and therefore are preferred agents as initial therapy as in our patient.
Conclusions: This case demonstrates an atypical presentation of NSCLC cancer. Being aware of the most common primary sites of metastasis to the eye (choroid) helped the inpatient team with the differential diagnosis which was communicated with the pathologist to help make a diagnosis.