Approach Considerations
Because NK/T-cell lymphoma (NKTCL) of the head and neck is an extremely rare malignancy, a standard treatment protocol has not yet been delineated. Treatment planning should include consultations with hematologists, oncologists, and radiation oncologists. [5, 25, 6, 28, 30, 7, 31, 32, 33, 34, 35]
Early stage, localized disease may be treated with local radiotherapy; however, monotherapy may result in high rates of local and distant recurrence (up to 49%). [6, 7] Currently recommended treatment includes CHOP (cyclophosphamide, doxorubicin, vincristine, prednisone) chemotherapy in conjunction with radiotherapy. The combination of treatments has yielded 5-year survival rates ranging from 20% to 80%. Unfortunately, disease progression commonly occurs despite treatment. [5, 25, 6, 28, 7, 31]
NKTCLs of the head and neck are associated with a high relapse rate, as well as a high degree of resistance to standard therapy. For these patients, alternative strategies have been investigated with some success. High-dose chemotherapy with or without total-body irradiation, followed by autologous stem cell rescue, has been used for patients with relapsing disease. In addition, treatments using the SMILE protocol (dexamethasone, methotrexate, ifosfamide, l-asparaginase, and etoposide) show promise, but adverse effects, including significant myelotoxicity, suggest that more research is needed to further develop this promising protocol. [32, 33, 34]
Takahara et al achieved good results with a treatment regimen for early stage nasal NKTL that included radiotherapy combined with infusion, through the superficial temporal artery, of ifosfamide, carboplatin, methotrexate, peplomycin, and etoposide. The study’s 12 patients achieved and maintained complete remission (observation period 39-111 mo), with copies of serum Epstein-Barr virus DNA dropping to undetectable levels in each patient. [36]
Surgical management of patients with NKTCL is limited to biopsy, stabilization of the airway if necessary, or debulking of disease.
Recent studies evaluating hematopoietic stem cell transplantation in patients with high-risk or refractory NKTCL show promise in select patients, but larger studies still need to be completed. [37] The presence of EBV in tumor cells may also prove to be an independent predictor of response to this and other therapies. [38]
Because of the relatively high mortality, low response rate, and high relapse rate after definitive treatment, patients should be regularly monitored by an otolaryngologist. The use of flexible nasopharyngoscopy is particularly important because of the high local recurrence rate for head and neck NKTCL.
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Coronal (left) and axial (right) CT scans of the sinus reveal severe pansinusitis with abnormal nasopharyngeal thickening, right facial edema and right temporal bone opacification.
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MRI revealed a low, non enhancing T1 signal in the right maxillary, ethmoid and sphenoid sinuses. (left) A high and inhomogeneous T2 signal suggested tumor involvement and destruction of the middle and inferior turbinates. (right)
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High-power photomicrograph of a nasopharyngeal mass that was diagnosed as natural killer (NK)–/T-cell lymphoma, nasal type. In this section stained with hematoxylin and eosin, a diffuse infiltrate of variably sized cells with irregularly shaped nuclei that contain coarsely granular chromatin is visible. In other areas of this tumor, necrosis and angiocentrism could be appreciated.
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In this photomicrograph, immunohistochemical staining shows neoplastic cells to be positive for the pan T-cell antigen CD3 (positive cells have a brown tinge).
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In this photomicrograph, immunohistochemical staining shows neoplastic cells to be positive for the natural killer (NK)–cell antigen CD56 (positive cells have a brown tinge).
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In this photomicrograph, immunohistochemical staining shows neoplastic cells to be focally positive for granzyme B (positive cells have a brown tinge).
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In this photomicrograph, in situ hybridization for Epstein-Barr virus RNA (EBER) shows positivity in neoplastic cells (positive cells have black nuclei).
