An older adult male presents with sudden onset of severe, tearing chest pain that radiates to the back. What is the most likely working diagnosis?

The most likely working diagnosis in this scenario is aortic dissection, primarily due to the description of the symptoms presented by the patient. Aortic dissection is characterized by sudden onset of severe, tearing chest pain, which can radiate to the back between the shoulder blades. This type of pain is often described as sharp or ripping and is only associated with aortic issues.

In aortic dissection, a tear in the inner layer of the aorta allows blood to flow between the layers of the arterial wall, which can lead to life-threatening complications. The typical presentation includes severe chest pain that can migrate, often described as coming in waves, and may be accompanied by other symptoms such as sweating, nausea, or a feeling of impending doom.

The other conditions listed do not typically present with the sudden, severe, tearing nature of the pain radiating to the back that is characteristic of an aortic dissection. Pulmonary embolism often presents with sudden onset of pleuritic chest pain, shortness of breath, and symptoms related to oxygen deprivation. A Pancoast tumor and spinal cancer would likely present with more chronic pain patterns and associated symptoms such as weight loss or neurological deficits rather than the acute and sharp description associated with aortic dissection