Synchronous rectal cancer and extranodal NK/T-cell lymphoma, nasal type: A case report

Synchronous primary malignancies involving solid tumors and aggressive lymphomas, such as extranodal NK/T-cell lymphoma, nasal type (ENKTL-NT), are exceedingly rare and pose significant diagnostic and therapeutic challenges. To our knowledge, no previously reported case of synchronous rectal adenocarcinoma and ENKTL-NT has been identified in the available literature.

A 64-year-old man presented with malaise, loss of appetite, toothache, gingival swelling, and a persistent facial sinus with purulent discharge.

Colonoscopy and histopathological examination confirmed moderately differentiated rectal adenocarcinoma with liver and sacral bone metastases. Histopathological and immunohistochemical analysis of the facial tissue confirmed ENKTL-NT, which was positive for Epstein‑Barr virus‑encoded small RNA, CD3, CD56, and T‑cell intracellular antigen-1.

The patient received 2 cycles of CHOP (cyclophosphamide, hydroxydaunorubicin/doxorubicin, Oncovin/vincristine, and prednisone) chemotherapy before a definitive diagnosis was established. Owing to rapid disease progression and poor nutritional status, no further lymphoma-specific therapy was feasible.

The patient died 3 months after diagnosis, underscoring the aggressive nature of ENKTL-NT and the risks associated with empirical chemotherapy.

This case highlights the critical need for early and accurate histopathological diagnosis in suspected lymphoma cases and emphasizes a multidisciplinary strategy to optimize management when synchronous aggressive malignancies are present. Anthracycline-based regimens should be avoided in ENKTL-NT.