Doctors examined a 60-year-old woman with a severe fever that had no clear cause. She had extremely high levels of ferritin, lactate dehydrogenase, and the immune protein IL-10. These markers are often seen in serious inflammatory conditions, but in this case, they pointed to a rare form of blood cancer called intravascular large B-cell lymphoma.
Tissue samples confirmed the presence of cancer cells inside the blood vessels. The patient then received R-CHOP immunochemotherapy. Her symptoms improved quickly, and follow-up scans showed a complete metabolic response with no signs of the disease remaining.
This single case report highlights that a specific combination of lab results can serve as a useful diagnostic clue. However, because the patient also developed a secondary inflammatory condition, it is difficult to say for sure if the lab pattern alone caused the diagnosis. More research is needed to confirm these findings in other patients. When standard biopsies fail to find cancer, doctors should consider re-evaluating PET-CT scans and these specific lab markers to reach a definitive diagnosis.