Genomic Profiling Reveals Medullary Thyroid Cancer Misdiagnosed as Lung Cancer

Mutations or other alterations in the RET gene have been implicated in a variety of malignancies – most commonly thyroid, but also chronic myelomonocytic leukemia, acute myeloid leukemia, and lung, breast, pancreatic, and colon cancers. Here we present a case of a gentlemen initially diagnosed with and treated for non-small cell lung adenocarcinoma. Genomic profiling of his tumor specimen revealed a RET point mutation with a known association with medullary thyroid cancer (MTC). Further pathological and molecular diagnostic evaluation confirmed a diagnosis of MTC, leading to a change in treatment from standard chemotherapy for non-small cell lung cancer to targeted therapy against RET and potential implications regarding inherited cancer risk for his offspring. The patient experienced a clinical response to treatment and several months of improved quality of life. This case illustrates the capacity of genomic profiling to uncover molecular drivers of disease and help ensure proper diagnosis and management of cancer.