Could it have been spirocercosis?

As a newly-minted veterinarian and aspirant pathologist, my first publication reported on an osteosarcoma at the thoracic inlet of a dog (Schröder 1976). The case was noteworthy because it was unusual for an osteosarcoma to originate on the axial skeleton, rather than on one of the long bones. Several years later, now wearing a parasitologist's hat, I have asked myself on numerous occasions if I might have missed an aetiological diagnosis of spirocercosis because I was too fixated on the neoplasm and its location. My only aide memoire is the paper from 1976, according to which I looked for and found metastases in the liver and lungs, but alas, no indication that I had also examined the oesophageal wall carefully.