Double Vision, Wrong Diagnosis
He walked into the clinic with double vision. His sinuses looked clear. His scans looked clean. His doctors treated him for a sinus infection and sent him home.
Weeks later, he was back — and losing his sight.
A Lymphoma That Hides in Plain Sight
Extranodal NK/T cell lymphoma, or ENKTL, is a rare type of non-Hodgkin lymphoma (a cancer of the lymph system that starts outside the lymph nodes). Unlike most blood cancers, ENKTL tends to grow in soft tissues of the face and upper airway — the nose, sinuses, and palate. It is strongly linked to the Epstein-Barr virus (EBV), the same virus that causes mono.
What makes ENKTL especially dangerous is how well it can disguise itself. Early in the disease, the tissue changes are subtle. Standard imaging — CT scans and MRIs — can look almost normal. And the symptoms? Facial swelling, nasal congestion, puffy eyes. The exact same things you'd see with a bad sinus infection.
When Scans Say One Thing and the Body Says Another
In this case, the patient's first nasal endoscopy (a camera inspection inside the nose) looked normal. His first MRI and CT showed no obvious mass. He was diagnosed with sinusitis and had surgery to open his sinuses — a common procedure called FESS (functional endoscopic sinus surgery).
But his condition worsened after surgery. A follow-up CT scan showed subtle changes near the muscle that controls downward eye movement. A suspicious area appeared near a gap in the bone at the base of the eye socket. Doctors now suspected orbital cellulitis — a bacterial infection of the tissue around the eye.
This doesn't mean ENKTL is always this hard to find, but when it mimics infection, multiple rounds of testing may be needed before the truth emerges.
The first tissue biopsy (removing a small piece of tissue for analysis) did not show cancer. It took a second biopsy. Then a third — samples taken from six different sites — combined with a test for Epstein-Barr virus, to finally confirm ENKTL.
How Tissue Testing Finally Cracked the Case
Think of cancer diagnosis like reading a hidden message — each biopsy gives you more letters. One sample from one location may not spell anything clear. But six samples from six sites, read alongside a positive EBV test, can finally reveal the word.
The EBV connection is key. ENKTL cells almost always carry traces of this virus, and detecting EBV in tissue is one of the most reliable ways to confirm the diagnosis when the standard cancer markers are ambiguous.
What They Found — and the Cost of Delay
By the time the diagnosis was confirmed, the patient had already lost vision in his right eye. Swelling from the growing lymphoma had pressed on the optic nerve long enough to cause permanent damage. Emergency surgery was performed to try to save his vision, but the window had already closed.
He then received chemotherapy — specifically a combination called GemOx (gemcitabine and oxaliplatin). After five rounds, his lymphoma went into remission (the cancer is no longer detectable). He remains in remission with no signs of recurrence.
That's Not the Full Story
The most important finding here is not the treatment — chemotherapy for ENKTL is not new. The real lesson is timing. Every week of misdiagnosis gave the tumor more time to press on the optic nerve. By the time the cancer was named, an irreversible outcome had already occurred.
Clinicians reviewing this case note that when facial swelling, eye symptoms, or tissue around the eye fails to respond to standard infection treatment, ENKTL should be on the radar — even if early scans look reassuring.
If you or someone you know has persistent swelling around the eyes, double vision, or facial puffiness that does not get better with antibiotics or sinus treatment, push for a specialist referral. Ask whether a tissue biopsy has been done — and if so, whether it was sent for both standard pathology and viral testing (specifically EBV).
This is rare, but it is not vanishingly rare. And it is treatable when caught early.
This is a single case report from one hospital. Case reports describe one patient's experience and cannot tell us how common a pattern is, or whether the same sequence would play out differently elsewhere. ENKTL is more prevalent in East Asia and Latin America than in Western countries, and the presentation described here — with purely eye-based symptoms at the start — is considered unusual even for this cancer.
This case adds to a small but growing body of literature urging clinicians to keep ENKTL on the differential (the list of possible diagnoses) whenever patients present with eye and facial symptoms that resist standard infection treatment. Researchers are working to identify biomarkers (measurable signals in blood or tissue) that could flag ENKTL earlier, before imaging and biopsies produce clear results. Faster, less invasive diagnostic tools could one day compress a months-long diagnostic journey into days.
