Pathwork Diagnostics

Initial presentation:
A 56 year old woman, otherwise healthy, presents with a large (approximately 10 cm) left inguinal mass on which an excisional biopsy is performed.

Work up:

Initial treatment for cancer of unknown primary:

• Carboplatin, Taxol®, and radiation

Pathwork® Tissue of Origin Test ordered.

Results - Tissue of Origin Test:
Interpretation from Pathwork Diagnostics’ pathologist: “The Tissue of Origin test indicates a Sarcoma origin in this case with HIGH PROBABILITY. The Tissue of Origin Test has effectively ruled out an origin from the 14 other tissue types whose scores ranged from 2.6 to 0.2. Similarity Scores below 5 indicate a greater than 99% probability of that tissue type not being the correct tissue of origin.

Follow Up:
The patient initially responded well to therapy, with a significant reduction in the size of the mass. However, 5 months later an excision and re-excision of the residual mass both showed positive margins. A PET/CT scan revealed a 7 cm mass with significant SUV in the muscle directly beneath the site of excision, consistent with sarcoma as the most likely primary.

“Without the clue from the Pathwork test, we would be unable to offer this kind of aggressive plan to the patient. We would be guessing on what to try next—tricky since the patient has a large open wound.”
-- Dr. Vinni Juneja, Bethesda, MD