Introduction and aim: Sinonasal malignant neoplasms are uncommon, with an annual incidence of less than 1/100,000. About 80% of these are squamous cell carcinoma. Adenocarcinoma and adenoid cystic carcinoma are next in frequency. Lymphoma of the nasal cavity, paranasal sinuses and nasopharynx are rare, constituting less than 5% of all extranodal lymphomas.
Case report: A 47-year-old man was referred to our hospital because of severe headache and progressive facial pain. He also complained of right-sided visual acuity. He had a manifest exopthalmia with disturbed eye movements. Nasoscopy showed a large mass with atypical appearance. CT and MRI showed a bilateral ethmoid mass invading the frontal sinuses, the right orbit, the lamina cribrosa and the right frontal cerebral region, and growing posteriorly through the choana. The first biopsies were inconclusive, showing only necrotic cells and purulent inflammation with epithelial elements. A larger biopsy demonstrated a high-grade malignant tumour with necrosis. The differential diagnosis of undifferentiated sinonasal carcinoma, undifferentiated neuro-endocrine tumour or T-cell lymphoma was suggested. In the meantime our patient developed high fever and sudden-onset pancytopenia. Bone marrow punction showed 65% blasts, leading to the diagnosis of AML type M2. He was immediately referred for chemotherapy, but died in intensive care before his first session. The biopsy of the sinonasal mass was diagnosed surprisingly as a natural killer cell lymphoma stage IVB.
Conclusions: Natural killer cell lymphoma is rare in Europe. The simultaneous appearance of a NK-cell lymphoma and acute myelogenous leukemia has, as far as we know, never been described in the English literature before.