Oncology and cancer diagnoses are a practice in repetition and nuance. We do many of the same tests and use the same treatments for many different types of neoplasia. When we hear certain symptoms combined with specific signalments, a differential list starts to form. Recommendations are made for additional diagnostics based on this list. Luckily, cancer tends to metastasize in patterns, even when it behaves just a bit differently. If it walks like a duck, talks like a duck, it’s has to be a duck, right? Not always. This presentation goes through 3 different cases that all present in a straightforward way with an obvious top differential for each one. As results come back and treatments initiated, we have to re-evaluate what we thought we knew.

The first case is a Boxer that presented with polycythemia and the primary vet noted a renal tumor. While not a common cancer, polycythemia is a well-documented paraneoplastic syndrome of malignant renal tumors, most notably renal carcinomas. Staging including thoracic radiographs and abdominal ultrasound were performed. Symptomatic treatment for the polycythemia was initiated to get her through to her nephrectomy. And yet…we end up with multiple myeloma.

The second case is a known lymphoma patient. He is a German Shepherd that successfully completed the CHOP protocol before returning shortly thereafter for a recheck with some lymph node enlargement and nasal congestion. An aspirate revealed that he was out of remission, and rescue protocols were initiated. While some response was noted, his congestion continued to get worse. Resistant lymphoma…and malignant melanoma.

The last case is an old cat with an oral mass under his tongue. Obviously, with no other symptoms and clean staging, it is a squamous cell carcinoma…or a pyogenic granuloma.

Diagnostics and staging for common cancers can reveal uncommon conditions that require a closer look.