Diagnostic Dilemma: A 60 year old man with a lung mass: is this metastasized esophagus cancer or a new primary lung cancer? (LG01-01)

Patient History:

One year ago a 60 year old man was diagnosed with esophageal cancer. Recently a solitary lung nodule was found. A fine needle aspiration of the nodule showed cancer, compatible with either a new lung primary or a metastatic tumor from the esophagus.

Original Diagnosis:

The biopsy was indeterminate for metastatic disease. The esophagus cancer was a moderately-differentiated, invasive adencarcinoma. The fine needle aspiration from the lung is a non-small cell carcinoma. The clinician cannot rule out metastatic disease. A PathFinderTG mutational analysis was requested for a definitive diagnosis.

RedPath Diagnosis:

The lung tumor is a new primary cancer of the lung and is not a metastasis of the prior esophageal cancer. The esophageal cancer shows allelic imbalance mutations of 1p, 9p, and 17q, with focal mutation of 3p and 21q. In contrast, the lung tumor shows mutations of 3p and 9p with focal mutation of 17p, and a point mutation of the K-ras-2 gene. Although both tumors have mutations in a 9p locus, they are on opposite alleles and are not shared.

Generic sample of PathFinderTG® quantitative test results. NOTE: A diagnostic interpretation of the quantitative test results is provided by the RedPath Pathologist.
Click here for test result explanation

Clinical Impact:

By establishing the lung nodule as a solitary primary lung tumor, the PathFinderTG results will allow the patient to be treated for low-stage lung cancer with surgery that will likely prove curative. A definitive diagnosis of a primary lung cancer saved the patient more toxic cancer therapy (e.g., chemo and radiation therapy) that would have accompanied a diagnosis of metastatic esophageal carcinoma.