Choroidal metastasis of pancreatic adenocarcinoma: case report

Pancreatic ductal adenocarcinoma (PDAC) accounts for 90% of all pancreatic carcinomas. Prognosis is poor with a worldwide five-year survival rate of 2-9%. Extent of metastasis is a prognostic factor. Most common metastatic sites include the liver, peritoneum, lung, and bones. We report a case of distant metastasis of PDAC to the left choroid.

This patient is a 59-year-old Caucasian male who initially presented with right flank pain progressing to exercise and activity impairment. Abdominal computed tomography scan showed a pancreatic tail mass subsequently confirmed as PDAC via endoscopic ultrasound with fine needle aspiration. Prior to treatment initiation, patient was referred to ophthalmology for acute vision changes. Evaluation revealed left eye pigmentary changes overlying subretinal fluid (SRF) along with peripheral retinal depigmentation indicative of choroidal metastasis. As of this report submission, patient has completed his initial 6-month course of gemcitabine/paclitaxel protein-bound/cisplatin with partial response. He remains active on his second line of chemotherapy. Visual disturbances and evidence of choroidal metastasis continue to resolve.

PDAC is often identified at a late stage, with metastasis or local advancement identified in 80-85% of first diagnoses. This is thought to account for its poor median survival of two to eleven months. The retinal choroid is an extremely rare site of PDAC metastasis, with less than ten cases reported in literature. In this patient, the choroid was the first confirmed metastatic site and represented distant metastasis. Nevertheless, this patient continues to do well and is expected to exceed the upper bound median survival of 11 months following systemic chemotherapy. From this case, we note that distant metastasis prior to treatment initiation may not predict worse prognosis. Systemic chemotherapy was effective in both primary tumor shrinkage as well as regression of choroidal metastasis, leading to improvement in visual symptoms. This suggests that while choroidal metastasis should not be missed in patients with PDAC, systemic chemotherapy may be effective in mitigating collateral symptomatology and thus preserving quality of life.