Extranodal nasal-type NK/T-cell lymphoma: computed tomography findings of head and neck involvement

Extranodal nasal-type natural killer (NK)/T-cell lymphoma (NKTL) is a rare, but distinct clinical entity in Asian populations. However, it is not uncommon for NKTL to be belatedly or postoperatively diagnosed because radiologists are not familiar with its radiological features.

To investigate the computed tomography (CT) findings in patients with extranodal nasal-type NKTL involving the head and neck.

Twenty-nine patients (18 male, 11 female; mean age 51.5 years) with pathologically proven extranodal nasal-type NKTL were enrolled in this study. Two head-and-neck radiologists retrospectively evaluated the CT scans with special attention to the primary site, the extent of involvement, and patterns of the lesions (i.e., morphologic features, ulceration or necrosis, and bone destruction).

The cases of nasal-type NKTL consisted of primary tumors arising from the sinonasal cavity in 13 patients (45%), the naso/oropharynx in three patients (10%), and simultaneous involvement in the nasal cavity and naso/oropharynx in 13 patients (45%). Fourteen patients (48%) showed tumor extension into adjacent structures. Of the 26 patients with involvement of the nasal cavity, 18 (69%) presented with an infiltrative pattern, seven (27%) with a polypoid pattern, and one (4%) with a combined pattern. Areas of necrosis within the tumor were observed in six patients (21%), bone destruction in five (17%), and regional lymphadenopathies in two (7%).

Extranodal NKTL may be initially suggested by CT findings in the head and neck. Clinicians should consider these findings indicative of the possibility of NKTL, and should perform a histopathologic confirmation to establish a diagnosis.