Sinonasal Non-Hodgkin Lymphoma

Michelle A. Michel, MD

Key Facts

Terminology

NHL-SN: Extranodal lymphoproliferative malignancy

Imaging

Appearance can mimic variety of neoplasms & aggressive inflammatory disorders
Predilection for nasal cavity > sinuses
CT: Homogeneous mass ± bone remodeling or destruction
- May be hyperdense due to high N:C ratio
MR: ↓ T2 signal
- Variable homogeneous enhancement
Imaging modality of choice: Multiplanar MR with post-contrast fat suppression

Top Differential Diagnoses

Sinonasal Wegener granulomatosis
Sinonasal adenocarcinoma
Esthesioneuroblastoma
Sinonasal squamous cell carcinoma

Pathology

3 pathologic subgroups
- B-cell (Western) phenotype
- T-cell (Asian) phenotype
- NKTL (Asian): Subtype of T cell

Clinical Issues

Male patient in 6th decade with nonspecific symptoms of nasal obstruction & discharge
Local radiotherapy (XRT) is primary treatment ± combination chemotherapy

Diagnostic Checklist

NHL could be included in DDx for almost any aggressive adult nasal soft tissue mass
Imaging clue to diagnosis: Presence of enlarged cervical nodes & Waldeyer lymphatic mass

Figure 1 (Left) Axial CECT shows a large NHL

centered in the nasal cavity with slightly heterogeneous enhancement. There is gross destruction of the nasal septum

. Obstructed secretions

are noted in both maxillary sinuses. (Right) Axial STIR MR shows a large lymphoma involving the nasal cavity and ethmoid sinuses. Hypointense long TR signal is characteristic of this tumor with high nuclear to cytoplasmic ratio. Note the involvement of the right orbit

with resulting proptosis.

Figure 2 (Left) Coronal bone CT shows the classic location of sinonasal non-Hodgkin lymphoma. The mass is centered around the nasal septum, and there is destruction of the septum

as well as multiple ethmoid septations

. (Right) Axial T1WI C+ FS MR demonstrates a large lymphoma filling the left nasal cavity. The septum is displaced

but not eroded. Homogeneous mild enhancement is present. Trapped secretions

are present in the left antrum.

TERMINOLOGY

Abbreviations

Sinonasal non-Hodgkin lymphoma (NHL-SN)
Diffuse large B-cell lymphoma (DLBCL)
Natural killer/T-cell lymphoma (NKTL)

Definitions

NHL-SN: Extranodal lymphoproliferative malignancy most often of B-cell, T-cell, or NK/T-cell origin
- NKTL: Subtype of peripheral T-cell lymphoma
  - NKTL previously called lethal midline granuloma, polymorphic reticulosis, angiocentric T-cell malignant lymphoma

IMAGING

General Features

Best diagnostic clue
- Homogeneous soft tissue mass with predilection for nasal cavity ± bone destruction
- Very nonspecific imaging features
  - NHL-SN can mimic variety of neoplasms & aggressive inflammatory disorders
Location
- Nasal cavity > maxillary > ethmoid > frontal sinuses
  - NKTL may have simultaneous involvement of nasopharynx & oropharynx in addition to sinonasal cavities
Size
- Usually between 2-5 cm
Morphology
- Variable: Diffusely infiltrative & ill-defined, nodular, or bulky mass