Destructive sheets of malignant lymphoid cells are present.
The malignant lymphoid infiltrate surrounds residual submucosal glands which are withering as a result.
An angiodestructive lymphoid infiltrate is disrupting this sinonasal vessel.
The infiltrate is made up of a mixture of normal-appearing small lymphocytes and large atypical lymphoid cells.
The large cells have irregular shaped nuclei with prominent nucleoli.
Vascular occlusion frequently occurs, resulting in large zones of infarction and karyorrhectic debris.
A high Ki-67 is an expected finding.
CD3 is positive in a more cytoplasmic pattern. .
CD45 highlights the cells as well.
This neoplasm is rare in the US and Europe, as most cases are found in Asia and in some parts of South America. This may relate to the populations exposed to EBV at an early age, since this pathogenesis is related to EBV. EBV genomes are integrated into the majority of tumor cells.
These extranodal tumors most commonly affect the nasal cavity and paranasal sinuses, but may also affect the nasopharynx, palate, skin, soft tissues, orbit, gastrointestinal tract, and testes. Leukemic dissemination may also occur.
Can arise in any age, but average age of presentation is 60-70. Presenting signs are variable and include constitutional "B" symptoms as well as site specific signs such as epistaxis, facial or orbital swelling and/or pain, nasal obstruction, etc.
Unfortunately, these lymphomas have a tendency to be chemoresistent. Early stage, localized disease is thereofre often treated with local radiotherapy. However, because radiation alone is associated with a high local and distant recurrence rate, the addition of CHOP (cyclophosphamide, doxorubicin, vincristine, prednisone) chemotherapy is recommended.
Sinonasal T/NK lymphoma is an aggressive neoplasm which, compares to other lymphomas in the head and neck region, carries a much higher mortality rate and a decreased response to traditional chemotherapy and radiation therapy regimens. This lymphoma shows a higher relapse rate compared to T-cell lymphomas arising in the same region. Overall median survival is approximately 1 year, and shorter for those with leukemic dissemination of tumor cells.
One dreaded complication is hHemophagocytic syndrome, which is associated with fever, marked pancytopenia, hemophagocytic histiocytes in the bone marrow, and rapid liver function deterioration. This complication is higher in T/NK cell lymphoma than other lymphomas.